How to make a foundation for a reinforced greenhouse c. We make the foundation for the greenhouse: the choice of material and construction technology
Today, a greenhouse or greenhouse can be found on almost any summer cottage and personal plot, and these are no longer homemade products from window frames, but quite worthy products from manufacturers, made of polycarbonate.
Most often, such structures are advised to be installed on the foundation, which causes some bewilderment among summer residents. Why is this needed? Isn't it easier to just assemble a greenhouse on bare ground without bothering yourself with extra work? Still, in order to make a foundation for a greenhouse with your own hands, you will have to spend some time and money.
Is it necessary to make a foundation for a greenhouse?
Polycarbonate greenhouses have a fairly tangible weight, therefore, for their installation, it is necessary to make a foundation. The fact is that a structure installed directly on the ground is not only susceptible to corrosion, at least its metal parts, it can still be washed away by groundwater or spring floods. And this leads to a distortion of the greenhouse and its subsequent destruction.
Another option does not save when it is dug into the ground. Winters in Russia are cold, which leads to deep freezing of the soil, which, under the influence of heaving forces, simply squeezes the supports of the structure out of the ground. Therefore, for a durable and reliable installation of a greenhouse, you just need to make a foundation for a greenhouse with your own hands, which will firmly fix the structure in a stable position.
What foundation is used for a polycarbonate greenhouse?
How to make a foundation for a greenhouse with your own hands depends, firstly, on the type of soil on which it is planned to install the greenhouse. Secondly, on the size, and to a greater extent - on the weight of the greenhouse.
Therefore, first of all, it is worth considering what, in principle, foundations are used for polycarbonate greenhouses, and then choose one of them. For all its dimensions, a greenhouse is considered not a particularly heavy and large structure, therefore, it is still not worth making a solid foundation for a greenhouse with your own hands, such as a monolithic one. Although in some cases it is also used, but more on that later. Basically, the following are made:
- Point foundation.
- From ready-made concrete blocks.
- Made of bricks.
- From a bar.
- Monolithic base.
These are the most common foundations, which are most often made as a foundation for a greenhouse with your own hands. A stable and even support is imperatively required under polycarbonate, since with distortions this material begins to crack and becomes unusable, and the above listed bases completely provide the necessary static.
Point foundation
This type of foundation cannot even be called a full-fledged foundation, rather, it is a props for the frame of the greenhouse, but it has every right to be used.
The main goal is to give stability to the frame - it does. Moreover, the material used to make the posts is selected depending on the weight of the greenhouse: the larger it is, the stronger the material should be. For small greenhouses, cuttings are used; for larger greenhouses, it is better to put concrete blocks.
Such a foundation for a polycarbonate greenhouse is made by hand only for use in the summer, since it does not retain heat. Another disadvantage is that insects, especially pests, do not encounter any obstacle on their way to cultivated plants.
But such a foundation can be made very simply and quickly: blocks or timber from which low hemp is cut are installed in the corners of the greenhouse and along the perimeter every meter. This type of foundation refers to a temporary foundation and can be easily dismantled when the greenhouse is moved.
The foundation is made of wooden beams
A base made of timber is another type of mobile foundation that can be easily disassembled, as a result of which the structure can be easily rearranged to another site. Therefore, they make a foundation from a bar for a polycarbonate greenhouse with their own hands in the event that a permanent place for the structure has not yet been chosen, and it will most likely be transferred. In addition, the base is quite inexpensive, and installation takes no more than one day.
In addition, the tree provides the correct microclimate in the greenhouse due to its ability to well absorb excess moisture from the air, and, if necessary, to give it away.
One of the disadvantages of using such a base is its fragility, since even a tree treated with an antiseptic and water-repellent agent is subject to destruction. For the manufacture of such a base, as a rule, 10x10 cm is used.
How to make a frame from a wooden bar?
Before installing the foundation for the greenhouse with your own hands, you must carefully level the surface of the site under the polycarbonate. To do this, remove the top layer of soil, level the site and cut a small ditch around the perimeter 10 cm deep and 20 cm wide.It is good if the greenhouse has already been purchased and you know its dimensions, otherwise it’s time to decide on the type of greenhouse.
A crushed stone pillow is poured at the bottom of the trench, which will drain excess water, or a layer of waterproofing is laid. They hammer the frame out of the timber, be sure to check the perpendicularity of the corners and the horizontalness of the surface. The corners are reinforced with a building corner.
The made frame is treated with an antiseptic and lowered into a trench, the free space is covered with soil.
A similar foundation for a greenhouse from a bar with your own hands can be made from a smaller material, for example, 50x50 mm bars or 50x150 mm boards, if the structure is not particularly large in size.
Concrete block base
This type of foundation is more solid and provides good waterproofing of the structure, which is very important for maintaining optimal humidity in the greenhouse.
Therefore, the most good option will make such a foundation for a greenhouse with his own hands on damp plots of land, on peat or swampy soils.
First of all, it is necessary to mark the plot of land on which the installation of the greenhouse will be carried out. To do this, we level the selected area and mark the perimeter of the structure with pegs and a rope.
Installing Blocks
After marking, it is necessary to dig a ditch 25 cm wide and 30-40 cm deep under the future foundation so that the marking cord runs exactly in the middle. At the bottom of the trench, a drainage backfill of crushed stone and sand 10 cm high is laid, which is carefully rammed. To do this, the top layer of sand is spilled with water, and the ramming takes place in a natural way.
A concrete solution is brought in and poured halfway into the ditch. Concrete blocks are laid around the perimeter, which must be leveled. Separate blocks are placed strictly in the corners. The remaining concrete is poured over and smoothed with a spatula.
Make this strip foundation under a greenhouse with your own hands it is quite possible in a few hours, and you can install a greenhouse in 2-3 days.
Concrete strip base
Another option for how to make a foundation for a greenhouse with your own hands in the form of a tape is to make it out of concrete. At the same time, to strengthen the structure during pouring, reinforcement in the form of metal rods is laid.
If the soil is dense and not prone to crumbling, the concrete solution can be poured directly into the ditch. In the case of loose and loose soil in the prepared trench, it is necessary to install formwork from boards. It is not difficult to assemble the device, the main thing is to observe the verticality of the walls. The size of the formwork depends on the height of the planned foundation: if it is planned to be raised above the ground, then the walls of the formwork must also be mounted at this height.
Concrete is poured into the formwork. If the prepared solution is not enough for one-step pouring, it is poured in layers. In doing so, try to lay the concrete as evenly as possible, as this will extend the life of the foundation. The last layer must be leveled with a spatula.
Concrete-brick foundation
With proper manufacture, this type of foundation is second only to a reinforced concrete foundation in terms of strength characteristics. At the same time, brick has the same properties as wood, it absorbs moisture well, and this guarantees an optimal microclimate for plants.
On the other hand, this material is quite expensive and it is advisable to make a foundation from fired brick only if there is an opportunity to purchase such products inexpensively.
For this, a concrete tape is made flush with the ground, as discussed above. When pouring, anchors or pieces of metal reinforcement are placed around the entire perimeter and wait for the concrete to set. After about a week, bricks can be laid on the tape, while the reinforcement should be inside the masonry seams.
Monolithic foundation
Another type of base can be poured from concrete, which is usually used to install large greenhouses, glass greenhouses, or if the soil on the site has increased heaving. This option is used only in exceptional cases, since making a foundation for a greenhouse from polycarbonate with your own hands in the form of a monolithic base is a rather costly event both in time and in money.
Preparing the area for pouring is the same as for any other base. It is cleared of the top fertile soil layer, after which a pit is dug under the foundation 30-40 cm deep, which is covered with geotextiles or any other waterproofing. If the soil contains a lot of water, you can do a little drainage system from trenches covered with pieces of roofing material, or lay drainage pipes.
Pouring concrete
Formwork is made of boards and a layer of crushed stone and sand with a total height of 10 cm is poured into the pit with a mandatory pouring for tamping. A reinforcing sheaf is placed in the formwork and poured with concrete. If necessary, insert reinforcing bars or anchors to secure the frame to the base.
It is possible to install a greenhouse on such a foundation only after the concrete has completely dried, which can last 21-28 days. At the same time, all the time while the solution is setting, its surface must be periodically moistened in order to avoid the appearance of cracks and violation of the integrity of the base.
Although such a foundation requires a lot of labor and considerable cash costs, its service life, which is about 50 years, more than compensates for everything.
In addition to these basic types of foundations, several other types of foundations are used, for example, from a metal profile or on screw piles... Some craftsmen combine the above installation methods, and especially inventive individuals can make a foundation for a greenhouse with their own hands from improvised material, for example, from glass bottles.
What foundation to use for a glass greenhouse?
We should also mention a glass greenhouse, which is also often used on summer cottages... Due to its characteristics, this structure is much more demanding both in terms of stability and protection from damage. Therefore, the do-it-yourself foundation is made mainly in the form of a concrete monolithic or strip base. Unlike the basement for a polycarbonate greenhouse, the base for a glass structure must be buried to the level of freezing of the ground.
If the greenhouse is small, it is permissible to use a metal or point foundation. However, such a foundation will not provide sufficient thermal insulation, therefore, the heat consumption in the greenhouse will increase. At the same time, it is not worth making a base from a wooden bar, and even more so of boards, for a greenhouse from glass, since wood will not provide sufficient immobility of the structure.
From all of the above, we can conclude: how long you make the right foundation for your greenhouse depends on how long it will last.
Greenhouses for growing greens and vegetables are made of lightweight materials. But, like other overall structures, they require the arrangement of a reliable and solid foundation, which will evenly distribute the load exerted on the support frame of the greenhouse.
Why do you need a foundation for a greenhouse
The foundation for the greenhouse plays the role of a supporting structure, which gives the supporting frame of the structure strength, reliability and safety. Plants planted in greenhouses built on different types foundation, are more protected from the destructive effects of moisture, insects and small rodents.
The presence of the foundation makes the greenhouse structure more stable and durable
In addition, having a foundation allows you to avoid problems such as:
- windage of the building - oversized greenhouses sheathed with polycarbonate and plastic wrap, with strong gusts of wind, they can shift relative to their original position. When installing the foundation, the greenhouse frame is attached to the strapping of the supporting base, which eliminates any displacement of the greenhouse;
- poor thermal insulation - a greenhouse built on a foundation will be located 15-30 cm above ground level. Even a slight rise helps to save up to 15% of thermal energy;
- short service life - the foundation insulates the support frame of the greenhouse and the covering material from contact with the ground. This reduces the risk of moisture absorption from the surface of the ground and the formation of rot on the wooden structures of the greenhouse, which in turn increases the life of the structure.
Despite the many clear advantages, the load-bearing base is not always made in the form of a foundation. For example, for greenhouses and small greenhouses made of plastic pipes, the construction of a foundation is unjustified. In the fall, these structures are easier to disassemble and put away for storage until next season.
In fact, the foundation for the greenhouse is erected only in cases where the structure is large and stationary. For polycarbonate greenhouses or old window frames, the construction of the foundation is mandatory, since these structures are large and cannot be disassembled for the winter. Without a reliable supporting base, the support frame of these greenhouses can be supported. Especially during the period of snow melting, when the soil is mobile and oversaturated with moisture.
Base types
Foundations for greenhouses of various designs practically does not differ from load-bearing foundations, which are used for the construction of low-rise residential buildings, small-sized residential buildings, technical premises, etc. The main difference between the foundation for a greenhouse is that its depth is much higher than the level of freezing of the soil.
Point type is a type of foundation made of bricks and beams
For the North-West region of Russia, the freezing depth varies from 100–130 cm, and the depth of foundations for greenhouses rarely exceeds 80 cm. This applies to both medium-sized structures for growing greenery and flowers, and large-sized polycarbonate greenhouses.
As a foundation for greenhouses, such types of bases are used as:
![](https://i1.wp.com/kakpostroit.su/wp-content/uploads/2017/07/uteplennyy-lentochnyy-fundament-dlya-teplicy.jpg)
For the construction of load-bearing foundations for greenhouses, similar materials are used, as well as for the construction of foundations for one- or two-story buildings. As a rule, wooden beams, concrete mix, bricks, foam blocks, steel posts are used.
When erecting strip and point types of foundations, both one material and a combination of several are used. For example, when constructing a columnar foundation made of reinforced concrete, a wooden beam of the corresponding section can be used for the construction of a grillage. When arranging a strip base, a strapping of a thick edged board or timber is very often used.
A monolithic foundation for a greenhouse is built quite rarely - it is expensive, time consuming and ineffective. A monolithic concrete slab completely covers the fertile soil layer, which is not suitable for the tasks for which greenhouses are built. Usually monolithic foundation It is used for flower greenhouses when the plants already have soil and are in free-standing boxes, baskets and racks.
What type of foundation to choose
The most popular type of greenhouse foundation is a strip foundation. But its use is not always rational, since different areas, even within the same dacha economy, may have a different type of soil and the level of groundwater occurrence.
When choosing a foundation for a greenhouse, you should take into account the type of soil and the level of occurrence of groundwater
Therefore, when choosing a foundation for a greenhouse, it should be borne in mind that:
- shallow strip foundation is used in conditions when the groundwater is low on the site. At the same time, the soil is not prone to heaving and is mostly represented by sand and gravel deposits, which quickly absorb and filter a large volume of storm water. If there is clay soil at the place where the greenhouse will be erected, then before the foundation it must be replaced with a sand and gravel cushion;
- columnar and pile foundations with a wooden grillage are erected in areas where there is a high level of groundwater and excess moisture in the soil. It is determined quite simply: if after precipitation there are puddles on the site for a long time, and water accumulates in the newly dug hole, then the soil is oversaturated with moisture. And also point types of bases are erected on heaving soils when it is planned to build an overall greenhouse. For example, on the site with clay soil when building a greenhouse 10 m long, 3 m wide and 2 m high;
- a monolithic or slab type of supporting base is constructed when building greenhouses on unstable types of soils. These types of soil include: loam, sandy loam, clay, peat. A heavy and monolithic base will dampen uneven heaving and soil mobility, keeping the support structure and greenhouse cladding intact.
From a financial point of view, the most affordable type of foundation is a columnar concrete base with a wooden grillage. If desired, concrete can be replaced with cobblestone or brick, but this will only increase the cost of the structure. In addition, working with a brick is somewhat more difficult than with a concrete mixture.
Concrete or block strip foundations are ideal in terms of price-performance ratio. When constructing small greenhouses, the concrete mixture or blocks can be replaced with a wooden beam treated with bitumen varnish or mastic.
A monolithic foundation is the most expensive, since a large amount of steel reinforcement is used for pouring it and concrete mix... If we take into account the pace of construction, then for a monolithic base it will also take more time - complete drying of the concrete mixture occurs after 28 days.
Polycarbonate greenhouse base
Polycarbonate greenhouses are a support frame made of a 20 × 20 or 25 × 25 mm galvanized pipe and a covering material in the form of cellular polycarbonate. Usually this type of greenhouse is made in the factory, but if desired, a polycarbonate greenhouse can be designed and built with your own hands. The weight of the structure and the choice of foundation directly depend on the size of the greenhouse.
Concrete strip base is the optimal type of foundation for polycarbonate greenhouses
For example, take a typical polycarbonate greenhouse from a random manufacturer. The weight of the greenhouse frame measuring 6 × 3 m, excluding polycarbonate, does not exceed 68 kg. A greenhouse of 8 × 3 m has a supporting structure weight of no more than 76 kg. The total weight of polycarbonate sheets for cladding, even taking into account the stock, will not exceed 20 kg.
From these data, we can conclude that for the construction of polycarbonate greenhouses, which will be erected in typical summer cottages, a columnar, block or strip foundation can be used. If the owner of the plot has sufficient funds, then it is possible to build a greenhouse on a pile foundation.
If it is necessary to save money, it is allowed to build a greenhouse on a shallow wooden belt made of a bar, treated with an antiseptic or hydrophobic composition.
Large-sized greenhouses with a length of more than 10 m are best erected on a tape insulated base, especially if artificial heating of the soil will be supplied for year-round use of the structure. To insulate the foundation, extruded polystyrene foam or foam of appropriate density is used.
Detailed instructions on how to equip a strip base under a polycarbonate greenhouse will be described in the section below.
From a bar
Greenhouses based on wooden frames made of edged boards or bar rarely have large sizes, therefore, a columnar base made of concrete, brick or foam block is used as a foundation.
For greenhouses made of window frames, it is better to use a point type of foundation with a timber strapping
The main task of the foundation in this case is to raise the grillage above ground level in order to protect the wooden frame from the harmful effects of moisture. The grillage, as a rule, is made from a bar of the corresponding section. For additional protection of the grillage and greenhouse frame, a wood preservative is used. If the size of the greenhouse exceeds 8 × 3 m, then it is better to fill in a shallow strip foundation 25-30 cm wide as a base.
If we are talking about greenhouses made of window frames, then it is better to use the simplest and most affordable types of foundation, which can be quickly built without significant financial costs. For example, for winter greenhouses made of frames, a columnar foundation made of bricks with timber strapping is ideal.
If the window frames are old, then even after restoration their service life will not exceed 3-5 years. In this case, it is recommended to completely abandon columnar base and build a greenhouse only on a wooden belt. This will be enough so that the structure of the greenhouse is not affected by dampness and moisture. The main thing is to prepare well the place on the site where the structure will be located.
How to make a foundation for greenhouses with your own hands
Before proceeding with the manufacture of the foundation and the construction of the greenhouse, preparatory work should be carried out. To do this, you need to do the following:
![](https://i1.wp.com/kakpostroit.su/wp-content/uploads/2017/07/proektirovanie-fundamenta-dlya-teplicy.jpg)
After carrying out preparatory activities, procurement and delivery of materials to the territory land plot, you can proceed to the construction of the foundation and the construction of the greenhouse.
The technology of installing a supporting base from a bar
For the manufacture of a wooden base, a beam of 20 × 20 or 20 × 25 cm will be used.As fasteners, it is better to use galvanized self-tapping screws 70 mm long, a reinforced corner 150x150x65 mm and reinforced plates 180 × 65. The thickness of the metal of the fasteners is at least 2 mm.
To make a point foundation for a greenhouse, you can use a wooden beam 20 × 20 cm
As a tool, you will need to prepare a hacksaw for wood, a screwdriver and a building level. If a columnar foundation is being built, then a bayonet shovel and a hand drill will be needed.
If you only need to make a wooden frame that will fit on a prepared plot of land, then for this you need to prepare 2 long and short blanks. The workpieces are fastened at the corners using self-tapping screws and reinforced corners.
For example, we will describe the technology for constructing a columnar foundation with a wooden frame made of a bar as a grillage. The technology for building a point foundation from a bar consists of the following:
- The marking of the prepared area is in progress. For this, wooden pegs and nylon thread are used. The pegs are driven in along the perimeter of the greenhouse, after which a thread is pulled between them.
- At the corners and the length of the greenhouse, the pit places for the supports are indicated. The step between the supports is 2 m. If necessary, a place is marked for the intermediate support along the width of the greenhouse on each side.
The depth of the holes for the installation of supports should be no more than 2/3 of the length of the support
- With the help of a drill and a shovel, a hole is formed under the supports at the corners and the length of the greenhouse. The depth of the pits should be equal to 2/3 of the length of the support to be buried. For example, for a support of 90 cm, the depth of the pit must be at least 60 cm.
- At the bottom of each pit, fine-grained sand with a layer of 7–10 cm is poured and compacted well to obtain a dense sand cushion. If necessary, the sand is slightly moistened.
A reinforced corner is used to assemble the grillage
- A support from a bar is installed in the pits, which are prepared in advance in the required quantity. The voids between the support and the pit walls are filled with sand, crushed stone or gravel. After installation, each support is level checked.
- U-shaped fasteners 160x70x160 mm are mounted on the end part of the supports to fix the grillage. After that, taking into account the size of the greenhouse, blanks are prepared from a bar for assembling a belt over point supports.
Wooden beams are connected using reinforced plates and self-tapping screws 70 mm long
- Prepared workpieces from a 20 × 20 mm bar are placed on supports and fixed with self-tapping screws 70 mm long. If it is necessary to connect the grillage by weight, then a reinforced plate or edged board 50-60 cm long is used. A reinforced corner is used to connect the timber at the corners.
At the end of the work, the assembled structure is checked by level. If there are any shortcomings, then they should be eliminated before the frame of the greenhouse is constructed. Before assembling the supporting frame of the greenhouse, the wooden foundation is treated with an antiseptic.
Concrete strip foundation pouring technology
For the construction of the strip foundation, ready-made concrete mix M300 is required. If you need to save money, you can use dry mixes from the manufacturer of the corresponding brand.
For mixing, it is better to use a concrete mixer or a construction mixer for concrete. In addition, you will need steel reinforcement with a cross section of 8–12 mm and a welding machine. For the assembly of the formwork, you can use an edged board. The main thing is that it is strong. Any nails or self-tapping screws with a length of 40-50 mm are suitable as fasteners.
The technology of pouring a strip foundation for a greenhouse consists of the following stages:
- A marking of the site for the construction of a greenhouse is carried out using pegs and a thread that is stretched between them. Taking into account the markings, a trench is dug up to a depth of 80 cm. The width of the trench is no more than 30 cm. The bottom of the trench is carefully leveled.
The depth of the trench for the greenhouse foundation can reach 60-80 cm
- At the bottom of the trench, 2 layers of roofing material are laid. Crushed stone of fraction 20-40 and fine-grained sand are poured onto the laid insulation. The thickness of each layer is no more than 10 cm. The sand and gravel cushion must be well tamped.
Reinforcement of the foundation will be performed using steel reinforcement with a cross section of up to 12 mm
- A reinforcing frame of steel reinforcement is formed, consisting of an upper, middle and lower belt with 2 rods in each. The distance between parallel rods is no more than 20 cm. To connect them, vertical ties are used, which are installed in increments of 30-50 cm. A detailed knitting scheme for the frame is shown in the photo above.
During installation, the formwork panels are pulled together using bars
- In a trench with a reinforcing belt, edged board shields are installed. If there is plywood or sheet metal, then they can also be used as formwork. On the outside of the boards, spacers are installed from a board or edged bar. When installing, it should be borne in mind that the foundation will rise 30-40 cm above the ground level.
25-28 days after pouring the foundation, you can start building a greenhouse
- They begin to prepare the concrete mixture and gradually pour it from any corner of the trench. After pouring 30–40 liters of concrete mixture, it is thoroughly rammed using a special tool or a reinforcement rod. Subsequent pouring then continues until all formwork segments have been filled.
When finished with pouring, the foundation is covered with plastic wrap and left to dry for 25-28 days. After 4 weeks, you can remove the formwork and prepare the supporting base for the construction of the greenhouse.
For this, the foundation is treated with bitumen mastic 2 times. If necessary, foam or expanded polystyrene is glued to the mastic, on top of which roofing material is glued. It is optimal if the joints between the sheets of roofing material are glued with mastic and heated with a blowtorch.
Video: point foundation for a greenhouse made of pipes
The foundation for a greenhouse allows not only to extend the service life of the structure, but also helps to avoid problems associated with the breakdown of the support frame due to its mobility under load. It does not matter what size of the greenhouse the foundation will be built under. Even a supporting base made of a bar, laid on the ground, will help to avoid many problems during the operation of the greenhouse.
Like any structure, a greenhouse must be a solid, stable and reliable structure in order to fully perform its functions. The foundation on which it is being built is responsible for their high-quality implementation. How to make a foundation for a greenhouse, and what type to choose in order to ensure the required operating conditions - frequent question owners of personal plots and private houses.
Why is a foundation for a greenhouse necessary?
A large stationary greenhouse, unlike small seasonal greenhouses and portable structures, requires installation on a stationary foundation, which is a solid and stable foundation. This need is due to the requirements for the reliability and safety of the structure:
- Large weight and height of the structure in the presence of strong gusts of wind can be subject to windage, in the absence of a reliable and stable support;
- The presence of the foundation assumes the independence of the structure from ground moisture and atmospheric precipitation;
- Reliable protection against weeds and ground animals and insects;
- Improving the energy efficiency of the building;
- Extension of the service life of the building, due to isolation from the earth's surface and susceptibility to destruction;
- Protects the crop from the penetration of cold and adverse weather conditions.
Most of all, polycarbonate greenhouses are in demand and widespread, which also require the installation of a foundation to improve the quality and strength of the structure. Seasonality, size and characteristics of the soil dictate their own conditions when the question arises of how to make a foundation for a greenhouse from polycarbonate.
Varieties of foundations
There are mainly two types of base structures used for polycarbonate greenhouses:
- Tape;
- Surface.
Their construction is almost the same, with the only difference that the construction of the strip foundation requires a deeper trench.
Depending on the materials used for the construction of the greenhouse base, the bases for their installation can be:
- lumber;
- block;
- concrete and brick;
- slab.
Which better foundation for a polycarbonate greenhouse, you can determine if you know the advantages and disadvantages of each type.
Lumber foundation
Wooden beams are the cheapest and most affordable material from which the base for a polycarbonate greenhouse can be made. This type of foundation is easy to install, and does not require special tools and specialized equipment. The timber construction is well suited to a lightweight polycarbonate greenhouse.
But such a foundation is susceptible to the destructive effects of moisture that is present in the soil and therefore requires frequent replacement. It can be operated for no more than 5-6 years, and then it must be replaced, since during this period it can begin to rot and have destruction from harmful insects.
To erect such a foundation, it is necessary to prepare a wooden beam, the side of which is at least 100 mm. At the site of the greenhouse installation, make markings for the foundation, observing strict geometry at the corners. Dig a trench according to the markings made and bury the timber in the soil by half its thickness. To protect against premature exposure to moisture, it is recommended to insulate the timber with roofing material or special moisture-proof mastic. The resulting structure at the joints can be fastened with iron staples for greater strength. For a visual reference, you can watch the video:
Block foundation
Such a base is both strong protection and copes well with the supporting function of the greenhouse structure. Such a foundation is especially optimal for soil with high moisture, due to its waterproofing properties.
The sequence of work when constructing a block foundation consists of the following works:
- at the first stage, the place for the foundation is marked;
- pegs are driven in at the places of the supposed corners, and the thread is pulled, for greater accuracy;
- a trench is dug with a depth of slightly more than the depth of freezing of the soil and a width of about 30 cm;
- the bottom of the trench is covered with a 10 cm layer of gravel;
- concrete mix is being poured;
- the blocks are installed in the uncured solution and they are aligned using the mounting level (if there are voids in the blocks, they are poured with concrete or compacted;
Important! The height of the foundation level must be level with the ground.
With the help of a trowel, the concrete surface of the base is cleaned and leveled, and concrete mortar is added to the seams.
Concrete-brick foundation
Bricks laid on a concrete base make the greenhouse structure even more stable and reliable. But this type of base is not applicable to year-round greenhouses, as it is a representative of a shallow type, not protecting from severe frosts and freezing of the soil.
Making such a foundation will not be difficult. To erect it, you will need a trench about 10 cm deep and no more than 20 cm wide. Further, a formwork is placed in this trench, which reliably protects it from debris. Concrete is poured into the installed formwork, the top layer of which must coincide with the ground plane. A wooden board is applied from above, at the level of which the entire perimeter of the foundation is leveled.
At the next stage, it is necessary to hammer in anchor bolts (diameter 12 mm) around the entire perimeter, which will strengthen the fastening of the frame. When the concrete mixture is completely dry (a week and a half), you can start laying the brick layer. In this case, it is worth observing the rule according to which the bolts should be located at the joints of the bricks, which are then sealed with cement mortar.
Slab foundation
It is the most difficult to install such a foundation, but at the same time it provides reliable isolation not only from water and pests, but also creates conditions for the long-term operation of the greenhouse. The presence of a drainage well helps to solve the problem of communications, ensuring that excess water is drained through the hole. Such a foundation requires a more serious approach and accurate calculations.
The rules for installing such a foundation consist in a certain sequence of actions:
- a place for the greenhouse is selected and its marking is done;
- a pit about 30 cm deep is pulled out over the entire area of the future structure;
- along the perimeter, the pit is fenced with formwork;
- the bottom of the pit is covered with a layer of wet sand, and gravel is poured on top. The poured mixture is tamped;
- reinforcement is done by installing a special mesh;
- after the inner space is concreted and its surface is leveled;
- anchor bolts are installed in the solidified base around the perimeter;
Important! For proper drying and preventing the top layer of the concrete mixture from drying out, it is recommended to periodically moisten it.
Point foundation
If necessary, installation small greenhouse seasonal use, making a durable and complex foundation is not always advisable. In this case, you can install the structure on a simpler base - a point foundation. It does not protect against weeds and pests, but it is done quickly and does not require special tools and time to work.
The installation procedure consists of the following actions:
- the territory of the proposed greenhouse is marked on the site;
- in the corners, 0.5 meter columns are driven into the ground, each of which has been pretreated with an antiseptic composition;
- wooden posts are placed around the entire perimeter at a distance of about 1 meter;
- a building corner is attached to wooden posts, on which the greenhouse frame will be installed.
Glass bottle foundation
In search of savings on building materials and while searching for a durable and strong material, some summer residents prefer to use a wide variety of materials for the foundation for the greenhouse. Such a base retains heat well and does not require large material costs. Glass base installation rules:
- along the perimeter of the future place for the greenhouse, a trench 30 cm wide is pulled out, to a depth slightly deeper than the soil freezes;
- the trench is poured with a small layer of concrete mix, into which glass bottles are installed in a horizontal position;
- another layer of concrete is poured on top and leveled;
- a formwork with a height of 30 cm is installed along the perimeter of the site;
- another layer of concrete mixture is poured into which glass bottles are installed again in a horizontal position, with the neck inside the future greenhouse house;
- concrete mixture is poured from above again;
- the alternating layers should be repeated until the height of the foundation is equal to the height of the formwork;
- with the last layer, concrete is poured and leveled.
Important! When laying the glass foundation, the container must be empty, and if a solution gets inside, then it must be removed.
Requirements for the foundation for a polycarbonate greenhouse
A polycarbonate greenhouse is a fairly light structure, but at the same time it requires a solid foundation. Therefore, when choosing the type of foundation, one should take into account such important factors as:
- the size of the greenhouse - the larger its area, the stronger the base should be;
- features of the soil on which it will be installed - the depth of freezing, the presence of groundwater, the type of soil.
The main functions of the foundation are to create reliable support and protection, which it can perform if it meets such requirements as:
- resistance to atmospheric phenomena;
- strength, for good and high-quality support of the frame of the greenhouse house;
- compliance with the dimensions of the building.
The resistance of the greenhouse to the influence of the environment and atmospheric phenomena is important during periods of spring thawing and rising groundwater levels. In such a situation, an incorrectly installed foundation can begin to stagger and lead to a violation of the geometry of the structure or its destruction. In terms of strength, it is important that the foundation is able to handle the weight of the building and does not fall apart. The size match is important not only in terms of aesthetics, but also improves the overall stability of the greenhouse.
A correctly chosen type of base will ensure the durability and stability of the polycarbonate greenhouse, protect the plants from bad weather and cold, and provide the correct microclimate inside. It is better to decide which foundation for a polycarbonate greenhouse should be installed in each specific case, taking into account the characteristics of the soil and the dimensions of the future building, as well as the material side of the issue. Without a good and high-quality foundation, even the best greenhouse will not perform its functions in full.
In the construction of a greenhouse, the structure of the aboveground part is of paramount importance. But the foundation must not be forgotten either. Otherwise, the work can go to dust. The base for the greenhouse can be made with your own hands from different materials.
Greenhouse foundation: purpose
In everyday life, a greenhouse is often called any structure that allows you to create a zone with an artificial climate on a garden plot. This is not entirely correct, since temporary objects of this type, consisting only of enclosing structures and used only for several months, are not greenhouses in the full sense of the word. These are greenhouses and cold nurseries, including the arched ones that are popular today, which may well do without a foundation. For stability, it is enough to attach them to pins driven into the ground and a heavy plank frame laid directly on the ground.
For a greenhouse of light construction, the foundation is optional.
A real greenhouse is also used in winter under much more severe conditions. The foundation is very desirable for her and here's why:
- Provides support on stable ground. Everyone has seen how the top layer of the soil, which seems so reliable and solid in the summer, turns into mush in the off-season due to rains or melting snow. It would be extremely unreasonable to install a greenhouse on such a treacherous base, burdened with insulation, heating and lighting. To prevent the structure from sagging, it is better to lean on the underlying soil layers, which are not affected by weather factors.
- Securely fixes the building on the ground. Equipped with the equipment already mentioned, a capital greenhouse, by definition, cannot be squat and streamlined, like, for example, an arched greenhouse, so the wind acts on it with much greater force. The consequences of the accident are also different: if the plastic "shell" of the cold nursery is carried away, nothing terrible will happen; if the greenhouse is overturned, then literally thousands of costs will fly away to the wind.
- Significantly reduces heat loss. In winter conditions, when the temperature difference inside and outside is large enough, any gap becomes the cause of colossal heat loss. If the greenhouse is simply placed on the ground, it will blow under the walls. If you equip the structure with a base, the walls are as if buried, which excludes blowing. Additionally, the foundation prevents heat leakage through the ground, which accounts for 10% of the total heat loss.
- Protects the interior from the penetration of pests living in the ground - a mole and a bear. And also the penetration of rhizomes growing around the weeds is excluded.
- Improves the operating conditions of the lower part of the greenhouse. Thanks to the foundation, it is raised above the ground, which means that it is less exposed to the moisture that saturates the top layer of the soil.
Capital greenhouse needs foundation
Varieties of foundations for greenhouses
The following types of foundations are erected under the greenhouses:
- Strip foundation. It is a frame on the crossbars (strips) of the greenhouse walls resting along the entire length. Such a foundation fulfills all the functions that were listed in the previous section.
The strip foundation is a reinforced concrete monolithic strip
- Plate. Such a foundation has to be erected in special conditions, when the soil is too weak or too saturated with water (swampy area). A monolithic reinforced concrete slab is poured under the entire structure, so that the bearing area becomes maximum, and the specific pressure on the ground, respectively, minimum. A significant drawback of the base is its high cost.
Foundation slab is a material-intensive and expensive structure
- Columnar or pile. This foundation is also called point. Instead of one continuous tape, several pillars are erected under the wall. Protection against heat loss and shrews is not provided with such a base, but it costs much less than a tape one. It is quite suitable for greenhouses that are operated only in the warm season - they do not need soil insulation.
Column foundation consists of concrete supports
Since the bearing area of the columnar / pile foundation less than that of the tape, the specific pressure on the ground increases greatly. Therefore, such structures can be erected only under relatively light frame greenhouses or built of foam blocks or a similar material (aerated concrete).
A columnar foundation differs from a pile foundation in a way of construction:
![](https://i1.wp.com/legkovmeste.ru/wp-content/uploads/2017/11/svaynyy-fundament.jpg)
The device of the pile foundation is unlikely to be up to the shoulder of an ordinary summer resident, since this requires special equipment - a diesel hammer (also called a pile driver). Another thing is the construction of bored piles. In fact, this is the same columnar foundation, but it is arranged much more in a simple way than the classic version. This explains its demand for individual construction.
A bored pile is arranged by drilling a well into which reinforcement cage and concrete is poured
Material selection
Foundations can be built from various materials: wood, concrete, brick, etc.
Wood
Someone, perhaps, the idea of building a foundation from a wooden beam will seem somewhat wild. Nevertheless, this option is resorted to quite often. There are reasons for this:
- such a base is extremely cheap;
- is built very quickly;
- It can be easily dismantled and reused, which is convenient if it is necessary to move the greenhouse to a new place (this is done if the soil in the old place has been depleted).
From wooden beams, you can build a foundation for a greenhouse
A wooden foundation will be especially appropriate for a greenhouse, which is supposed to be in operation for only a few years. Under such conditions, the main disadvantage of wood - a short service life - ceases to be of any importance.
The greenhouse on a timber foundation is easy to move to another place
Concrete
It would be more correct to say - reinforced concrete. The fact is that artificial stone, as concrete is also called, is extremely poorly holding tensile forces. Therefore, it is never used in its pure form, but only with steel bar reinforcement.
The construction of reinforced concrete structures is a very time-consuming process. But on the other hand, for any size and shape, they turn out to be monolithic, which means that they are as strong as possible.
Foundation blocks
These are ready-made reinforced concrete modules, from which it is much easier to build a foundation than from concrete in the form of a solution. In contrast to the monolithic, such a foundation is called precast.
Block foundation suitable for wet soils
The strip foundation does not have to be made in a monolithic design, pouring directly on the construction site. It is faster and easier to fold it from reinforced concrete foundation blocks produced by various companies. Before buying blocks, read the rules for their selection:
![](https://i2.wp.com/legkovmeste.ru/wp-content/uploads/2017/11/fundamentnye-bloki.jpeg)
The last parameter is indicated by two characteristics:
- strength grade: denoted by the letter "M" and a number indicating the ultimate load in kg / cm 2 (for example, M150);
- class: denoted by the letter "B" and a number indicating the ultimate load in MPa (megapascals).
Strength grade is a kind of "theoretical strength", which is determined based on the cement grade and the properties of other ingredients. The class is determined by testing an already cast sample. It characterizes the strength of concrete more objectively: concretes of the same brand and composition under different hardening conditions can acquire different strength classes.
Brick
Quite often, a columnar foundation is laid out from this material. Solid red fired brick should be used: it has good moisture resistance, and therefore high frost resistance. Silicate and hollow bricks are not suitable for such tasks.
Ceramic solid fired brick is required for the construction of the foundation
The disadvantage of brickwork is that, unlike reinforced concrete structures, it is not monolithic.
Natural stone
The advantage of the material lies in the combination of cheapness and such essential qualities in construction as strength and moisture resistance. From pieces of stone with interlayers of cement-sand mortar, a strip foundation is assembled, which is called rubble concrete (but it is precisely called pieces of stone).
A large stone of natural origin is used in the construction of rubble concrete foundations
Calculation of the base
When designing a foundation, attention should be paid to two parameters - the specific pressure on the ground and the depth of laying.
Specific ground pressure
Specific pressure is calculated according to the following formula: P = M / S, where: M is the mass of the entire structure, including the foundation itself, kg; S is the support area of the foundation, cm 2.
The P value should not exceed the P max value - the bearing capacity of the soil at the construction site. The latter should ideally be calculated by a licensed firm based on geological surveys, but such research is expensive and is usually ordered for the construction of large industrial greenhouses.
An ordinary summer resident who intends to build a greenhouse for his own needs can be guided by the experience of neighbors who once ordered a similar study when building a house.
Another way is to set the specific pressure P, which is guaranteed to be able to withstand any soil. This value is 1 kg / cm 2.
Depth of laying
In principle, to lean on a stable ground and securely fix the building, it is enough to deepen the foundation by 50 cm.But there is an important circumstance: if the temperature of the soil below the base of the foundation in extreme cold will drop below 0 ° C, and at the same time the soil will be saturated with water, then on the structure from below will be affected by the so-called frost heaving forces. They are due to the property of water to increase its volume when freezing. Even a heavy structure, heaving forces will be squeezed out without difficulty.
The forces of frost heaving are distributed unevenly, which can lead to cracking and even fracture of the foundation tape
Soils with well-pronounced drainage properties - sandy and stony - usually do not contain a lot of moisture (unless the groundwater is under the surface itself), so the owners of such plots during construction can safely deepen to the same 0.5 m. Another thing is clayey soils and loams, exhibiting waterproof properties and therefore retaining moisture: the forces of frost heaving are very characteristic for them. The owner of a plot with a similar soil should choose one of three options:
- To deepen the base of the foundation to the depth of freezing of the soil, typical for a given geographical latitude (preferably with a small margin of 15–20 cm).
- Surround the building with a semblance of a blind area made of insulation, thereby reducing the depth of freezing of the soil in this zone. Then the depth of the foundation can be reduced.
- Take the laying depth equal to 0.5 m, but remove the rest of the soil to the freezing depth and replace it with well-compacted sandy one. The width of the sand backfill should slightly exceed the width of the foundation.
Obviously, the forces of frost heaving act on the foundation from the outside, therefore, for its insulation, if such is planned, only fairly strong materials can be used. The best is extruded polystyrene foam, which has a scanty coefficient of thermal conductivity of 0.034 W / m * C and at the same time can withstand loads of 50 t / m2 (used as an insulating substrate for road surfaces).
Instruments
The builder must have:
- roulette;
- a set for marking: pegs or metal pins (often reinforcing rods are used) with a coil of cord or fishing line;
- shovels of two types: bayonet and shovel;
- plumb line and level;
- a hacksaw and an ax;
- hammer;
- grinder with a cutting disc for metal (for cutting reinforcement);
- hook for knitting a reinforcing cage;
- construction vibrator (for vibrating concrete).
If a decision is made to prepare concrete for the foundation on your own, you will need a concrete mixer with a drive (the solution mixed in the trough with a shovel will turn out to be half as strong).
Step-by-step instructions for building a foundation
Any construction begins with the marking of the territory. Pegs are driven into the ground, between which a cord is pulled, outlining the contours of the future greenhouse. In this process, there is only one subtlety: it is necessary to achieve equality of the diagonals of the marked 4-gon - this is a sign that all its corners are right.
Now let's take a closer look at the process of building some types of foundations.
Wooden base
A foundation from a bar is constructed in the following sequence:
- It is necessary to prepare a dried (moisture - 20–25%) timber with a section of 100x150 mm or 150x150 mm. Of the species, larch is the most preferred.
For the foundation, a beam with a section of 100x150 or 150x150 mm is used
- The timber is treated twice with an antiseptic, after which it is wrapped with glassine. The latter can be shot with a construction stapler.
Glassine provides waterproofing of the timber
- A trench is dug along the entire perimeter of the future greenhouse, somewhat larger in width than the timber.
The trench should be slightly wider than the timber to be laid
- The bottom and walls of the recess are covered with rolled waterproofing material - roofing felt or tar paper.
- The beams are laid in the trench. Between themselves, both in the corners and in straight sections, they are connected in a half-tree or in a thorn with fixation with long nails.
Half-tree connection is the easiest way
- For greater reliability in a wooden foundation, you can drill through vertical holes and "sew" it to the ground base with long metal pins (reinforcing rods are suitable).
- The space between the side edges of the timber and the walls of the trench is filled with sand.
The greenhouse frame is fastened to this base using corners and self-tapping screws.
Excellent material for wooden foundation decommissioned railway sleepers will serve. The construction of them is assembled in the same way as from a regular bar. Only during work should you be careful: the sleepers are impregnated with creosote, which, in contact with the skin of the hands, causes a burning sensation.
Video: construction of a wooden foundation for a polycarbonate greenhouse
Monolithic strip foundation
For the device of the tape base, you need to do the following:
- Dig a trench around the perimeter of a slightly wider width than the future foundation. The optimum width of the concrete tape is 35–40 cm.
- At the bottom of the excavation, arrange a sand backfill, which must be well compacted (for this, it must be watered). The thickness of the backfill after compaction should be approximately 10 cm.
- Lay a layer of crushed stone or gravel of the same thickness on top, followed by tamping.
Sand and crushed stone are filled up in layers with obligatory compaction
- From boards, thick plywood or chipboard, build a formwork - a form for a concrete tape. All elements are fastened securely, since the concrete solution is quite heavy. Between the walls of the trench and the formwork, it is necessary to install supporting bars that will not allow it to disperse. Above ground level, the formwork should rise by about 20 cm. It is advisable to set its upper edges strictly horizontally with the help of a level, in order to use it later as beacons when leveling concrete. It is better to wrap the formwork elements with polyethylene - then they will not be damaged by the moisture present in the solution and can be used later for other purposes.
Plywood sheets along the top must be tied with bars
- Install reinforcement and embedded parts in the formwork for fixing the greenhouse frame. For small buildings (up to 10 m 2), the reinforcement can be simplified: steel pins 60–70 cm long are driven into the ground at regular intervals. They must be driven in half the length. The pins are tied with thick wire. The sections should be used as long as possible so that the reinforcement is solid).
Reinforcing bars are tied with soft wire
- If the size of the greenhouse is larger, but its area does not exceed 15 m 2, you can apply the same reinforcement scheme, only the wire is tied in two rows.
- For larger buildings, a full-fledged frame is laid in the foundation: above and below - working belts of three longitudinal rows of reinforcing rods with a diameter of 10-12 mm, all this is connected by vertical and horizontal transverse reinforcement with a diameter of 6 mm. It is impossible to connect the elements of the frame by welding - the reinforcement in the zone of the welded seam loses its strength. They must be tied with annealed wire.
It is convenient to knit the reinforcement frame on the surface, and then lower it into the formwork
- The concrete cover on all sides of the frame must be 40 mm thick. To ensure the presence of such a layer from below, the frame is laid on special plastic bosses or suspended from a wire.
- Embeds should also be attached to the reinforcement, which will protrude from the concrete and be used to fasten the frame of the greenhouse.
- Pour concrete.
For pouring the concrete mixture, it is advisable to use a technique or a construction hose.
- Wait for the concrete to mature. This usually takes about 28 days. Concrete requires water to mature, so when it dries, it will not be able to gain sufficient strength. In hot weather, the structure should be kept under plastic wrap and periodically watered. The formwork can be dismantled 10 days after pouring.
- Perform foundation waterproofing works. The structure is pasted over with roofing material, bitumen mastic is used as an adhesive.
Roll material (roofing material), glued to the reinforced concrete tape by means of bitumen mastic
- Backfill the trench.
Concrete can be prepared independently according to the following recipe:
- cement grade M300 or M400: 1 mass part;
- sand: 3 parts;
- crushed stone: 4–5 pieces;
- water: 4-4.5 parts.
For self-preparation of the mixture, it is better to rent a small concrete mixer. An easier way is to order concrete at the factory, from where it will be delivered by an auto mixer.
It is very important when pouring concrete to ensure that air is released, otherwise voids will form in the body of the foundation.
The best effect is given by a special tool - a vibrating plate. In its absence, you can pierce the freshly poured mortar with a reinforcing bar or a shovel.
Video: pouring a strip foundation under a greenhouse
Bored pile foundation
As already mentioned, this is a type of columnar foundation, the piles of which are made in a very simple way:
- In the corners of the future building, as well as along its walls with a step of 1.5-2 m, wells are made with a garden drill to the depth of freezing.
- A sand and gravel pad is placed at the bottom of each well as described above.
Civil engineers call a pile placement drawing a pile field
- Further, large-diameter plastic pipes are inserted into the wells. They will simultaneously play the role of formwork for concrete and its waterproofing. The pipes should rise somewhat above the ground, while their tops should lie in the same horizontal plane.
- In each pipe, a reinforcing cage is suspended in the form of a trihedral parallelepiped, the vertical edges of which are represented by rods with a diameter of 10-12 mm (this is the working part of the frame), and the transverse links are thinner, 6 mm in diameter. Mortgages are attached to the frames.
With the help of umbrellas, additional fastening of polystyrene foam to concrete is performed
Foundation finishing
If the greenhouse owner wishes to veneer the above-ground part of the foundation, then basement siding can be used for this. In comparison with the wall, it is more durable.
The cheapest is vinyl plinth siding. Its advantage lies in a wide variety of colors and textures: you can find varieties that imitate brickwork, natural stone (including marble), wood, etc. Metal siding is more durable and reliable, but also more expensive.
Siding panels are attached to the crate from a special metal profile, but if you want to save money, you can also make it from wooden blocks.
The crate for the panels can be made of wood or metal.
Also, the cladding of the foundation can be made with slabs made of natural stone (a rather expensive option) or its artificial analogue. These materials are laid on mortar or glue.
There are a lot of varieties of foundations for a greenhouse. But none of them suggests insurmountable difficulties in construction. When choosing a foundation, it is necessary to take into account the material from which the greenhouse is made, its weight, as well as the type of soil. Follow the recommendations, and the design will be reliable and durable.
The foundation for the greenhouse is the foundation that will ensure the stability, integrity, strength of the building. Do you build with your own hands or is it possible to buy finished structure and perform independent installation on the site, the site must be equipped in accordance with the specifics of the structure.
In the article we will tell you why you need a base, what is the best foundation for a greenhouse made of polycarbonate, glass, with a frame made of timber, for metal structures, lightweight buildings made of boards, film, old window frames, etc. And we will give a detailed step by step instructions how to make a foundation for a polycarbonate greenhouse with your own hands.
Why does a greenhouse need a foundation
The foundation ensures the reliability, safety and stationarity of the building. But light structures on the site are of a temporary nature, so the question naturally arises: in general, in principle, do you need a foundation for a greenhouse made of polycarbonate or other materials and why? The answer is unequivocal - it is needed, it is a base that performs a number of important tasks:
- fixes the greenhouse frame, holds it in case of gusts of wind, heavy showers, flooding of the site and other atmospheric surprises;
- insulates the structure from contact with the ground, protects materials from the harmful effects of the soil, significantly extends the service life of the building;
- helps to keep up to 10% of heat inside, contributes to a favorable microclimate and saves on heating;
- prevents fog and cold air flows from entering the greenhouse;
- helps to protect the structure and crop from harmful insects and rodents.
How to make a foundation for a greenhouse with your own hands, a photo of a light structure on a tape
Types of foundations for greenhouses
There are 4 types of foundations in total, and each of them can be equipped as a greenhouse:
- tape;
- columnar;
- pile;
- slab.
The choice of the base depends on the specifics of the soil on the site, its relief features, the scale of the building, climatic conditions in the region, and many others. etc. Next, let's talk in detail about each type of foundation for a greenhouse and materials for its construction.
Tape
The strip foundation is the most demanded base for almost all types of buildings. According to the construction principle, it can be:
- not buried - lying on solid ground, it is enough to remove the upper, fertile layer, usually serves as a grillage for pile foundations;
- shallow - fits into a trench 700-800 mm deep, on a specially prepared pillow, such a device is not desirable if the area has high groundwater;
- buried - it is sunk 200-400 mm below the level of soil freezing, this parameter is individual, depends on the region, the average is 1200-1400 mm, the exact information can be seen from the table.
The foundation for a brick greenhouse, a diagram of the correct foundation
Optimal ratio, depth and height: 700: 300-400 mm. Before making a foundation for a greenhouse, you need to decide on the materials for the tape:
- Monolithic concrete, consisting of a reinforcing frame and filled with mortar.
- The base is made of special ready-made concrete blocks, connected with reinforcement.
- A rubble structure made of stones and clay.
- A tape made of bricks, foam blocks, it is still advisable to fill in a monolithic concrete base, build a basement on it.
- Construction of scrap materials: thick timber, bottles, logs, etc.
Shallow foundation for a greenhouse made of polycarbonate, from a bar on concrete supports
Good to know: It is faster and cheaper to make a foundation for a greenhouse from a bar with your own hands. But the tree does not tolerate physicochemical and biological influences, it is saturated with moisture in the soil, a fungus appears, signs of decay. To extend the service life, it is better to arrange the foundation for a greenhouse from a bar of hard wood, for example, larch, the frame must be impregnated with protective compounds, covered with bitumen mastic, machine oil, and pasted over with roofing material.One of the inexpensive ways to put a polycarbonate greenhouse on
Slab
A slab foundation is a solid, reliable foundation for construction in areas with high groundwater and unstable soil, the pyramids in the sand have just such a base. The greenhouse can be installed on a stove of two types:
- Floating - concrete site lies almost on the surface.
- The base with stiffening ribs is a combined structure made of concrete strips, a monolithic slab is tied to them on top. If the strip foundation must necessarily be closed along the contour, then in the case of a slab, this requirement is absent.
To organize the slab, a pit is dug with a depth of 300-700 mm, a sand-crushed stone pillow is laid on the bottom, covered with geotextiles, roofing felt, this helps to avoid silting. The optimal foundation thickness depends on the expected loads: for outbuildings and light greenhouses - 100 mm, for large stationary greenhouses, designed for the winter period, 200-250 mm.
As a rule, a slab foundation for a greenhouse is made of concrete, but tires filled with earth and other materials at hand can be used.
Scheme of arrangement of slab base
Columnar
A column foundation is a simple, inexpensive, fast way to set up a foundation. The pillars are deepened by 700-800 mm, for small buildings it may not be recessed into the ground. The optimal distance between the posts is 1.5-2.0 m.
Columnar foundation for a greenhouse can be made of materials:
- Bricklaying, rubble stone.
- Use ready-made T-shaped concrete pillars.
- Install, reinforce and fill with mortar metal, asbestos, roofing felt pipes.
- For the organization of an unsubmerged columnar foundation, foam blocks, flat rubble stones, even wooden stumps are suitable.
Diagram of the device of the pillars
A significant drawback of the columnar foundation for the greenhouse is the gap between the ground level and the base of the building, through which cold gets inside. Such conditions contradict the functionality of the building, so the perimeter should be insulated: make a brick strapping, sewn up with boards, etc.
The foundation for the greenhouse is made of foam blocks, the high base will protect the timber from harmful influences
Pile
A pile foundation is an ideal solution for building a greenhouse in a swampy or uneven area... It settles down below the level of soil freezing by 200-300 mm. There are 2 types of piles:
- driven - pipes, sleepers, channel;
- screw - pillars equipped with blades, which are immersed in the ground in a circular motion using a drill or special equipment.
The optimal installation of piles is 1.5 - 2.0 m from each other. After installation, the upper heads are sawn off to size and tied with a grillage, which ensures the integrity and strength of the structure. The grillage can be made of timber, sleepers or monolithic concrete.
Organization of a pile foundation for a greenhouse with a monolithic concrete grillage
Let's summarize
If you choose bases for glass structures, film structures, a base for structures made of old window frames, ready-made prefabricated metal structures, a foundation for a polycarbonate greenhouse, which one is better to say with some certainty is impossible. You should rely on geodetic studies, soil quality, dimensions and materials, the weight of the building, climatic conditions depend on them.
For capital warm buildings, it is recommended to make a strip foundation - this option is suitable for almost all conditions. Temporary and light greenhouses, in an effort to save money, can be safely installed on a point columnar base.
The inner structure of the tape base for the greenhouse
Polycarbonate greenhouse foundation - photo and step-by-step instructions
We will arrange a strip foundation for a greenhouse, size 3 * 6 m, with a high brick base and insulation around the perimeter.
Making a drawing
Before building a greenhouse, you should choose a project or make a drawing with your own hands, indicating the dimensions and main structural units. It also determines the materials, their quantity, the main stages of work. It is better to use a typical project and adapt it to your own conditions.
Typical Ergonomic Greenhouse Design
Choosing a place
The choice of location depends on the individual characteristics of the site. It is better to build a greenhouse from the southern and maximum windless side, behind the house. We clear the site from debris, tree roots, weeds. We fence off the perimeter with pegs, pull the rope, check the geometry. The diagonals must be equal. Remove the upper, soft layer of soil.
Foundation device
We dig a trench 800 mm deep around the perimeter. Align the bottom. We cover with roofing material for 2 layers, you can lay geotextiles. We fill in crushed stone, sandstone, layers of 100-200 mm, ram the pillow.
We install the reinforcing frame. There will be two horizontal belts, two parallel rods in each, vertical bundles every 300-500 mm. The reinforcement is corrugated, with a cross section of 8-12 mm. We put pebbles, 50 mm high, or stands on the bottom.
We put 2 lower horizontal rods, the distance between them is 200 mm, we lay smooth thin rods perpendicular to better preserve the shape of the frame. At the corners, we bend the reinforcement to the adjacent side, we go in 500 mm or more. Also, on the other hand, a double overlap is obtained to strengthen the structure. We drive in vertical rods, we tie the parts with wire. We mount the upper horizontal belt in the same way.
How to knit reinforcement correctly
The distance between the horizontal belts depends on the height of the greenhouse foundation. If the tape is 400 mm high, then there should be a distance of 300 mm between the upper and lower rods, +50 mm per concrete layer on each side. The width is calculated in the same way, if the overall dimension is 300 mm, then the frame is 200 mm. Remember, the height must be greater than the width of the tape.
We install formwork in the trench, it can be knocked-down boards from a board, moisture-resistant plywood, plastic durable panels. For the correct geometry, we make a bundle along the top of the lathing with bars, and on the outside we install spacers, they will hold the structure when poured with concrete.
For your information: In order to preserve heat in the greenhouse as much as possible, to protect the structure from harmful influences, the height of the foundation should be calculated in such a way that it rises 1/3 above ground level.The tape should be poured in at the same time, so that seams and cold bridges do not form. The proportions of the solution for the foundation for the greenhouse: cement (binder) - 1 part, sand - 3 parts, crushed stone, fraction up to 40 mm (preferably 10-20 mm) 4-5 parts, water 4-5 parts, until the consistency of thick sour cream. First, dry components are thoroughly mixed, then water is added.
In the photo, how to properly fill the base for a polycarbonate greenhouse with your own hands
Pour the mixture into the crate, ram it, remove the air. Bubbles in the hardened concrete will cause destruction. The solution must be hardened, until it is fully formed - 4 weeks, only then the foundation must be loaded.
We remove the formwork, glue the sides with roofing material or coat it with bitumen mastic for 2 layers, attach foam sheets on top, you can order insulation - PPU spraying. Cover the sheets with 2 layers of roofing material, overlap seams of 100-200 mm, seal with tape, weld with a blowtorch. Backfilling the soil. For horizontal waterproofing, roofing material is laid on top of the foundation under the greenhouse.
How to install a polycarbonate greenhouse on a foundation
On fresh concrete in the center of the tape, in the corners and every meter, it is recommended to install and release reinforcement for metal structures or special corners with welded anchors to the outside, for fixing the bars, the greenhouse frame will be attached to them. If the embeds were not provided during the pouring of the foundation for the greenhouse, then the frame can be fixed with anchor bolts.
Method of fastening the frame to the foundation
The installation of a polycarbonate greenhouse on the foundation has another important stage: in order to avoid drafts, ice, freezing, the gap formed when the base of the greenhouse adjoins the foundation is sealed with elastic sealants, a gasket with rubber edges is placed in the gap. This is especially important if the structure is insulated and it is planned to grow crops in it all year round. When equipping a winter greenhouse, do not forget about additional lighting and heating.