House on stilts foundation insulation. Ways of insulating a pile foundation in wooden houses. How to insulate a pile screw foundation with your own hands

In modern construction, there are many types of foundations. Each of them has its own characteristics and basic functions. But the most versatile foundation, suitable for almost any climatic conditions the pile-screw type is considered. This foundation is a metal, pile-and-beam structure. It protects the structure from groundwater, soil deformation and transfers the load to dense soil layers.

Why insulate a pile foundation

In areas with problem soil, where there are areas with floating soil layers, the optimal solution for building a house would be pile screw foundation... It will provide reliability in places with a high level of groundwater, in contrast to strip monolithic or prefabricated foundations.

The pile-and-beam structure and dynamic loads are not terrible. It is very durable and resistant to the process of soil heaving. Also, he is not afraid of the destructive effect of groundwater, since the screw piles are made of anti-corrosion steel.

Another advantage of this type of foundation is the relatively low cost, as well as the speed and ease of construction. The installation of one pile foundation will take only one working day for a team of experienced specialists.

But, despite a number of positive qualities, the pile-screw foundation has a number of negative features. A house built on piles does not have a basement and also has poor thermal insulation parameters.

There is a space between the floor and the ground that can be easily blown through. It is because of what the precious warmth leaves the house very quickly. This is especially noticeable with the onset of cold weather. Radiators don't do their job as warm air always goes up and the floors stay cold.

To solve this problem, you need to think about it even at the stage of designing a house - thermal insulation. Insulation of the pile-screw foundation occurs at the stage of working with the grillage in order to completely isolate it from external air flows. Ready houses can also be insulated, but it will not be as effective as thermal insulation during the construction phase.

Also, for high-quality and effective insulation of the pile-screw foundation, it is necessary to install a false base. It must exclude wind and precipitation from entering the free space between the soil and the house.

Materials for insulation of the foundation

When insulating the pile-screw foundation, it is necessary to pay attention to the false base and the grillage. These elements come into contact with the surface of the house and, when frozen, can transfer a low temperature to it. The screw piles themselves, immersed in the ground, do not need to be insulated.

When insulating a false base, it is necessary to choose a material that is not afraid of water and retains its thermal insulation properties even in a wet state. After all, a large amount of moisture emanates from the ground, which means that the insulation will be in a very humid environment. It must also be resistant to various salts and minerals in the soil. It is better to use high-density sheet materials or a liquid heat-insulating mixture when insulating a pile-screw foundation.

The most popular materials for insulating a pile-screw foundation are:

Styrofoam;
liquid penoizol;
foamed glass blocks;
extruded polystyrene foam or foam.

Penoplex and polystyrene have the same thermal conductivity, and also do not allow vapors to pass through. Penoizol also has a similar thermal conductivity, but allows moisture to pass through. It is better not to use mineral wool and basalt insulation, as they are not very convenient for installation.

Do-it-yourself pile-screw foundation insulation

It is necessary to start warming the foundation only after the grillage of the house has been waterproofed. Waterproofing membranes are perfect for this. The most budgetary option may be roofing felt or similar materials on a bitumen basis.

Attention! It is necessary to cover with waterproofing not only the upper surface of the grillage on which the walls of the house will be erected, but also all its other parts, together with the pile heads.

For the self-made construction and insulation of the false base, the following tools are required:

welding machine;
trowel, spatula, hammer, tape measure, knife;
low speed drill or screwdriver;
concrete mixer.

The false base of the pile-screw foundation does not bear any load, since its main task is to isolate the free space under the house from external factors.
The first option is to build a brick wall under the grillage. Its thickness should be half a brick. The second option is to close the free space with decorative panels that are attached to the grillage.

Creating a brick plinth

This option is more labor-intensive, but the efforts made will not be in vain. Since the brick base is as reliable as possible and has greater durability, while the decorative alternative is easily damaged.

Before erecting and insulating the basement, it is necessary to dig a trench around the house under the grillage. The depth of the trench should be 20-30 centimeters, and the width should be slightly larger than the brick.

The trench should be filled with concrete and allowed to harden. This will be a kind of foundation on which the brick base will be laid. Due to the shallow depth of the concrete, reinforcement with a reinforcement diameter of 10-12 mm should be used.

After the concrete has completely set and hardened, you can start building the walls of the brick basement. It should be laid in small sections 1-2 meters long. This is necessary in order to simplify the insulation on the surface of the base.

To fix the material selected for insulation, you will need specialized adhesives, which should not contain organic solvents.

Advice! A good option Ceresit CT83 glue will be used to fix the material on the base / plinth surface.

After insulating the basement, you need to close the brick wall with a decorative plug. The choice of materials is huge, suitable for everyone's preferences. You can also use plaster.

Creating a plinth with decorative panels

A much simpler way to erect and insulate a false base, as opposed to erecting a brick partition, is to install decorative panels. If you approach this issue seriously and competently, then this method will provide durable and reliable insulation of the pile-screw foundation.

To begin with, you should start choosing the supporting structure, on which the decorative panel of the false base and the material selected for insulation will actually be installed.

Advice! A good option when erecting a false base will be a frame made of a metal profile welded to the screw piles of the foundation.

The distance between the track profiles depends on the height of the free space between the floor of the house and the ground. Usually two or three longitudinal profile frames are enough.

A wooden beam will also cope well with the task of the frame, only it must be pre-treated with an antiseptic or mastic. The main thing is to protect the tree from rotting and insects.

Further, the cavity of the frame is filled with insulation. Styrofoam, penoplex or any other insulation. Do not forget about the thickness of the plates if penoplex is used for insulation. If it goes beyond the grillage, it will greatly complicate the installation of decorative panels.

After installing the thermal insulation material, a decorative fill should be installed on the grillage of the building using an adhesive mixture. The size of the decorative panels is also an important aspect. To ensure reliable fixation, it is necessary that the lower part goes into the ground to a depth of about 5 centimeters, and the upper part fits snugly against the grillage. In the place where the lower part of the panel is in contact with the ground, you need to dig a small ditch 10-15 centimeters deep and fill it with expanded clay.

Expanded clay filler has low thermal conductivity, which excludes the possibility of freezing of the structure at negative temperatures. Therefore, it will also help to reduce the heat loss of the building floor.

The choice of this option for a false base for a pile-screw foundation with vapor barrier materials (penoplex) implies the presence of natural ventilation. It is needed so that moisture does not accumulate in the internal space. Because of it, condensation will settle on the inside of the floor of the house, which can negatively affect the wooden structure. In order to allow air to circulate freely, special ventilation holes must be made. With the onset of cold weather, the holes should be closed with a plug or any heat-insulating material.

Minus of such a foundation- cold floor due to large open space under the house and soil. The only solution to this problem will be to insulate the pile foundation, which will allow not only to get a warmer house, but also an additional room under the house for household needs.

How to insulate a pile-screw foundation?

Before insulating the foundation on screw piles, it is worth considering a number of features of the building, its location, the height of the pile posts above the ground and the material from which they are made. Based on these conditions, insulation can be done in several ways:

Outside around the perimeter of the house.

Consists in the construction of the basement frame from the ground to the beginning of the walls of the house along the entire perimeter. Then, depending on the climate and financial capacity owners, it is insulated and cladding from the outside. This method is the only correct one when the floor is low from the ground.

Outside from the floor.

In some cases, when it is not possible to insulate the foundation in the first way (very high location of the floor from ground level due to the peculiarities of the location), only the outer side of the floor is insulated.

Complete.

It is an ideal method and consists in insulating the basement frame both outside and inside. This method of insulation can be broken down into several stages:

works on waterproofing the grillage and the metal piles themselves;
erection of the basement frame;
installation of insulation inside the basement;
fixing decorative panels to the plinth;
insulation of the inner side of the basement with expanded clay or soil;
floor insulation from the side of the basement.

Waterproofing works

Waterproofing works carried out in order to prevent moisture from entering the joints of the grillage and piles. If this is not done, then the metal elements of the structure will corrode over time, and the wooden ones will rot, which will lead to the destruction of the whole house. For this, a waterproofing material, for example roofing material, is placed at the point where the ends of the piles meet with the grillage and on the upper edges of the grillage itself at the point of contact with the wall.

Then a special mastic is applied to the entire metal structure of the foundation, and the tree is treated with impregnation with antiseptics. After the mastic and impregnation are completely dry (about 6-7 days), you can proceed directly to the insulation of the pile foundation.

Warming

Base / plinth of the pile-screw foundation

The basement frame can be erected and insulated at the same time two ways:

Erection of a wall of bricks.

For such a basement, a small, shallow reinforced foundation made of cement mortar, which in itself will be an additional insulation of the base. After the foundation has completely dried, a light wall is laid out in half a brick.

Installing metal rails for fastening decorative panels.

Metal guides are bolted or welded to the foundation piles, on which decorative panels, siding or corrugated board are then hung. The panels are also fixed with special fasteners or tile glue, depending on the design and material of the panels. In the corners, elements and drips covering the joints of the panels are installed.

With any method of insulation don't forget about the ventilation holes, which will prevent the accumulation of moisture inside the foundation space. The holes are recommended to be located on opposite sides of the plinth.

Styrofoam

Extruded polystyrene foam, due to its heat-insulating and noise-absorbing characteristics, is most preferable for insulating various foundations, especially pile foundations. And the small thickness of the sheet (3 cm) allows you to save the internal space of the basement floor.

Insulation of the pile foundation with expanded polystyrene is carried out as follows:

On the surface of the basement wall, if it is a brick wall or concrete, all cracks are eliminated. After that, the wall is treated with a primer for better fixing of the insulation sheets.
The polystyrene foam sheets are glued from the inside of the basement wall using glue-foam or adhesive composition. When using glue-foam, polystyrene foam is fixed for a while with special umbrellas in order to exclude deformation of the sheet when the foam swells.
The joints of the sheets are carefully foamed to exclude the "bridges" of cold.
For better insulation of the foundation, the sheets are glued in two layers.
To protect sheets of expanded polystyrene from mice and rats, a special metal mesh is installed on them.
In order to finally eliminate the possibility of blowing through the space under the house, it is advisable to add a little expanded clay or soil to the inside of the insulated basement.

Paul

Insulation of the floor on a pile foundation directly under the house inside the basement space produced in several stages:

a vapor barrier material is fixed to the floor from the outside of the house over the entire area;
a heater is installed on the vapor barrier, for example, expanded polystyrene;
the insulation is covered with plank sheathing.

Such a floor can be used both as a ready-made basement ceiling, as well as the only option for warming the pile-screw foundation if it is impossible to use other methods.

Thus, by thoroughly insulating the pile-grillage foundation, you will finally eliminate the problem of cold floors and significantly save on heating. And the correct observance of the stages of work and the accurate installation of insulation will help significantly increase the reliability and durability of your home.

The foundation on screw piles deserves more and more popularity when erecting support foundations in problem soils (heaving and deep-freezing soils; high groundwater level at the building site). Houses on screw piles can last for a long time, however, a distinctive feature of pile-type foundations is the reduced thermal insulation characteristics of the building being erected.

To improve the thermal insulation of the pile foundation, it is necessary to equip a basement fence, which reliably insulates the space between the building and the soil.

Basement insulation: technology and methods of work

The open space between the soil surface and the grillage significantly impairs the technical characteristics of the premises on the first floor of the house on piles: there is a significant decrease in temperature in winter; cold air masses contribute to the occurrence of drafts and condensation on the structures of a residential building, and the cost of heating the building increases.

Base / plinth erection technology

According to the technology of performing work on the insulation of pile-screw foundations, first you should erect a basement, and then proceed to the implementation of insulation by any of the existing methods.

The device of the basement of a house built on a pile-screw foundation can be performed in certain ways:

To begin with, it is necessary to lay the walls, covering the row of mounted screw piles, with a height from the line of the existing blind area to the lower chord of the house strapping.
Arrange a pick-up (false plinth) on a frame basis with an external cladding.

Basement belt masonry

Red brick is most suitable for the basement belt

For the masonry of the basement, only red ceramic bricks are used, which are most resistant to high humidity.

The masonry is carried out in half a brick, first you should prepare the foundation, for which they dig a trench along the perimeter of the building of the following dimensions:

Depth - 0.30 m.
Width - 0.250 m.

The bottom of the trench is carefully leveled, the excavation is filled with coarse sand to a height of about 0.10 m, after which the sand mixture is compacted with periodic moistening. A narrow reinforcing cage (mesh) of longitudinal and transverse rods is laid on a carefully rammed base, after which the structure is poured with a concrete mixture.

It is important to complete the concrete work within 1 day, which will ensure the strength of the structure without the formation of rough seams.

After the concrete mortar has completely hardened and sufficient strength has been gained, they begin to erect brick walls.

Zabirka: we build correctly

The pick-up on the pile-screw foundation is arranged as follows: first, metal rods are welded to the pile heads, which will serve as guides for fastening the panels. The next stage of work is welding of the vertical strips of the pick-up frame. Then, the foundation cladding shields are attached to the slats. It is very important to ensure that the lower edge of the cladding boards does not come into contact with the ground surface. Coarse sand is poured under the lower edge, while a slope from the house is provided to drain rain and snow water.

The foundation of a house on piles should be protected by laying a roll of waterproofing along a pick-up, while a protective roll carpet, when glued, should have a lower outlet, which is inserted into a sand bed, and then closed with a paved blind area.

The ways

Houses on screw piles necessarily require reliable insulation of the foundation. To ensure a comfortable microclimate inside the building on screw piles, it is necessary to perform a number of technological operations that improve the heat-saving characteristics of the screw-pile foundation.

Insulation of a pile foundation made of screw piles can be performed in the following ways:

Thermal protection device for the basement along the outer perimeter of the building.
Internal insulation of the building's basement on a foundation made of screw piles along the perimeter.
Insulation of ground floor structures.

Technology of external insulation of the base

Penoplex for external insulation of the basement

If it is necessary to insulate the base from the outside, proceed as follows:

Outdoor brick walls leveled, treated with a deep penetration primer for better adhesion to the insulation.

For insulation, plate materials are used, the best of which are expanded polystyrene and penoplex. Penoplex, unlike ordinary expanded polystyrene, has increased technical characteristics in terms of resistance to excessive moisture. The material is characterized by low flammability, does not deteriorate from low temperatures in winter, does not cause allergies and other diseases, and provides high rates of heat conservation.

The board insulation is strengthened with a special adhesive. The joints between the individual slabs are sealed with special care with polyurethane foam.

If the smallest gaps and cracks remain between the slabs, this will facilitate the penetration of moisture into the structures, cause condensation, rotting and the development of mold.

Reinforcing mesh is reinforced along the laid layer of slabs, the plinth is plastered, after which finishing is carried out in any way that will match the style of finishing the outer facade of the building.

Internal insulation technology of the base

Expanded clay - material for internal insulation

The basement floor of the pile-screw foundation is allowed to be insulated from the inside, for which the following technology is used:

Brick walls are insulated from the inside in the same way as outside, only they do without finishing the base of the pile-screw foundation base. Insulation is considered complete after laying the metal mesh over the insulation layer. It is very important to lay a protective layer from the inside of the basement, which is poured onto the basement. The basement of the pile-screw foundation can be insulated with sand or expanded clay, in this case expanded clay is a more reliable insulation for the basement of the pile-screw foundation.

Insulation of the floors of the first floor

It is possible to insulate the floors of the first floor in a house with a base of screw piles by arranging several layers of waterproofing and insulation using the following technology: cranial bars are laid on both sides of the lag, on which the subfloor is laid from the boards. Wooden products should be treated with an antiseptic. A layer of waterproofing, vapor barrier, insulation is laid on the rough floor, another protective layer is soundproofing and a finishing floor made of boards. On top of the boards, it is allowed to arrange a finishing coating of finishing materials for the floor. Insulation of the floors of the first floor is considered the most reliable type of insulation of buildings on pile foundations made of screw piles. Watch the video on what mistakes to avoid when insulating the floor.

In conclusion, I would like to note one nuance of performing the insulation of the foundation belt from the piles - in the basement it is necessary to provide holes in the opposite walls for airing the basement floor.

This is necessary to prevent the accumulation of vapors and condensation in the basement. Natural ventilation of the basement will reduce the risk of premature corrosion of piles and other metal structures, as well as reduce the risk of the spread of mold and mildew, which greatly damage the wood flooring.

The network contains a lot of materials about the cheapest type of foundation for a house - a pile-screw. You can find a detailed description of its properties and construction technology. There are articles containing such detailed step by step instructions on the installation of screw piles, that on the basis of the information given, even a "teapot" with a certain diligence and the availability of equipment will be able to install "screws" into the ground. Or competently supervise the actions of hired builders. However, almost few of the authors pay due attention to the question of how to properly insulate the pile-screw foundation. We will try to fill this gap.

Features of the pile-screw foundation

The pile-screw foundation is suitable for light buildings: frame, log and squared timber, from SIP panels. Supports - steel piles - are installed under the walls with a step of several meters. The support is a pipe with a sharp tip and a helical blade at the end. The screw pile resembles a screw both in shape and in the installation technology: it is literally screwed into the ground. It is advisable to connect the installed piles to each other with a metal corner on top, this will prevent their possible displacement. Often, in order to save money, the corner is not set, in this case the piles are connected by the support board of the frame or the lower crown of the log house installed directly on them.

Options for the device of pile-screw foundations. The most budgetary (top right) is the most common and is used in the construction of light houses

A properly constructed screw-pile foundation can withstand severe frosts, an unfinished and unused building can be safely left for the winter without being insulated. The foundation is practically not subject to the forces of frost heaving: the helical blades lie below the freezing depth, and insidious along the smooth pipes of the piles heaving ground slides without causing any damage to the building.

A seasonal dacha "on screws" does not need to be heat insulated at all. You can also leave the base open, leave it open. But if they live in the house all year round, you will need effective insulation of the pile foundation from the outside. Thermal insulation is needed in order to minimize heat loss through the floor of the first floor and thereby reduce heating costs. And also, in order to prevent freezing of communications introduced into the house in the basement. It is necessary to take into account a number of features of the screw design:

The initial absence of a vertical outer perimeter fence. You have to build it.

Initially, the basement of the house on stilts is open to all winds.

Often, screw foundations are erected on problem heaving soils.

The presence of free space between the ground and the overlap of the first floor.

As a rule, the soil under the house is damp.

In view of the above, there are three problems that will have to be solved when insulating a pile foundation: moisture in the underground, heaving of the soil and its freezing:

How to remove excess moisture from a subfloor

It is possible to completely waterproof the soil under the house. But this is economically unjustified, since we are talking about cheap construction. You can, of course, lay a plastic wrap on the ground, but this is a half measure. Moisture from the soil will inevitably flow into the space limited along the perimeter under the overlap of the first floor, if the house is not built in an arid area.

Inevitably, the question arises of protecting the structure of the first floor overlap from water. The vapor barrier of the floor is mandatory, and it must be made from below, from the subfloor. Therefore, when building a screw foundation, it is worth choosing such a height of piles so that a person can move and work in the underground. Otherwise, you will have to mount the lower vapor barrier, being above the frame, which is not very convenient. And if necessary, it will be impossible to repair or replace the insulation without opening the floor.

To remove excess moisture in the outer fence of the foundation, you will have to make ventilation holes. Air vents should be located on all four sides of the building; for a large house, it is desirable to have two pieces on each side, closer to the corners of the building.

To remove moisture from the subfloor, ventilation holes are made in the fencing of the basement of the pile foundation

The hole should be covered with a grill to prevent rodents and wasps from entering the subfloor. As for the size of the holes: SNiP recommends taking the total area of all holes in the base, equal to 1/400 total area the floor of the first floor of the house. For example, for a house of 8x8 m, eight air ducts with a diameter of 8 cm each will be required. The ventilation of the subfloor will be even better if the exhaust duct is brought out to the roof.

The air temperature in the underground in winter will be positive, but it will definitely not be hot there. This must be taken into account when arranging the overlap of the first floor, the layer of insulation must be sufficient, at least 15 cm. It is imperative to insulate the water supply and sewerage inlets.

How to avoid deformations from heaving effects of the soil

Fluffy soil (clay, loam) increases in volume during freezing, in winter its level rises. Jammed gates and rickety fences are the result of this very process. Arranging an external vertical fence and insulation of the base of the pile screw foundation, we are unlikely to bury it below the depth of soil freezing. Typically, the fence is lowered just below ground level. But in cold weather, heaving soil will rise and begin to put pressure on the foundation fence. The result will be deformation.

In order not to repair the fencing of the basement every spring, the heaving soil under it should be replaced with non-heaving soil: remove the clay and fill the coarse river sand into the trench. For central regions It is enough for Russia to make a replacement to a depth of 60 cm. It will also not be superfluous to lay a damper strip of foam plastic or other non-rotting material that can compress under load in the ground between the ground and the outer fence.

Under the basement fence, heaving soil should be replaced with sand

How to prevent freezing of soil under the foundation

Having made the vertical insulation of the foundation from screw piles only up to the ground level, we still will not achieve proper thermal insulation of the building. Wet winter soil is an excellent conductor of cold, frost will inevitably "make its way" under the house horizontally. The soil will freeze under the vertical fence, bypassing the insulated, but not recessed wall from below. It is possible to prevent soil freezing under the foundation by arranging the so-called "insulated blind area". Under the covering of the blind area (concrete, tiles, gravel, lawn) at a depth of 10-30 cm, a layer of thermal insulation must be laid horizontally. Extruded polystyrene foam is best suited for these purposes. It is necessary to make sure that the vertical and horizontal thermal insulation are connected without leaving a cold bridge for cold penetration into the subfloor.

How and how to close the basement of a house with a pile-screw foundation

The thermal insulation material needs to be placed somewhere, it needs a base. First of all, it is necessary to close the subfloor. What will be the insulation of the foundation on screw piles is primarily determined by the design of the outer fence of the basement. How to close the pile-screw foundation?

Fencing of the basement with brickwork

You can find a recommendation to make a screw foundation fence made of brick or rubble. Some developers do just that. However, you need to understand that for a brick wall it will not work (more precisely, it is irrational) to arrange a sufficiently reliable support and the strength of the structure is not guaranteed.

If the soil is heaving, in the place where the wall is supported, it should be removed to a depth of at least 80 cm, replacing it with sand. And to support the masonry, embed a reinforced mini-foundation with a cross section of at least 20x20 cm. Between the concrete and the brick, as well as the wooden support bar of the house box and the brick, it is necessary to lay a layer of roll waterproofing. The insulation will have to be placed on the inside of the subfloor during the masonry process. If the subfloor is high enough, it makes sense to make a hatch-manhole in it, then the insulation can be laid after the completion of the construction of the brick structure.

When installing a basement fence and a subfloor height that allows a person to move there, it is worth making a hatch-manhole

We do not consider the solution with a brick base to be rational. Having built the foundation and the house using the cheapest and "fastest" technology, it is illogical then to get involved in a long and rather expensive job with a stone fence. It is easier to build a lightweight subfloor fence along the frame.

If you make a brick fence of the screw foundation "for centuries", you will need a deep and expensive foundation for masonry. And if you save money, the strength of the structure is not guaranteed.

Base / plinth fencing with light stitching along the frame

How and from what to make a frame on screw piles?

You can make a metal frame - it is more reliable, more durable, but more complicated and more expensive. It is easier and more convenient to use a corner, with a pile pitch of 2 m, a 40x40 mm profile is sufficient. Having placed the corners horizontally with the shelf down, support them with wooden blocks, to which it will be easy to attach the skin. How to connect metal parts by welding or hardware is a matter of taste and availability of equipment. For fire safety purposes, welding work should be carried out before the installation of wooden structures on the supports.

Pile-screw foundation reinforced with an I-beam. The steel profile can serve as the basis for the frame, the bottom shelf of the profile will serve as a support for a wooden bar

It is easier and cheaper to make a wooden frame, from bars or boards. The wood must be pre-antiseptic, because it is wet in the subfield. It is better to fix the bars to steel pipes not with self-tapping screws, but with long bolts or ties. Under the heads of the bolts in the wood, you will have to drill a recess in order to place the fastener in a recessed position.

If it is not possible to drill steel piles, the wooden frame can be fixed to the pipes using a mounting strip. The metal tape must be tightened with effort and fixed to the frame element

Having built the frame, we will get a more or less solid base for attaching the sheathing and laying the basement insulation. As a cladding, you can use any moisture-resistant and not very heavy sheet material. Flat asbestos-cement sheets are very strong, durable and relatively inexpensive. Plastic siding, designed for sewing a basement, looks great. Even a "fence" metal profile and ordinary galvanized sheet steel will do.

Very lightweight plastic siding designed for plinth cladding very convincingly imitates natural stone or rustic brick

How and how to insulate the pile-screw foundation

How to choose a heater? First of all, it must be moisture resistant. Well suited hydrophobic synthetic materials: foam, EPS, polyethylene foam, etc. Of the mineral insulation, only foam glass is suitable, mineral (basalt and glass) wool - in no case. No organic thermal insulation materials will work. The final choice of thermal insulation material depends on where it is placed.

How to insulate the pile foundation along the frame, where to place the insulation? It is clear that from the inside of the underground, but here there are options:

Placement of the thermal insulation layer behind the sheathing frame

At first glance, the easiest way is to first fix the plinth plating directly to the frame, and then lay the insulation behind the frame. It is behind the frame, and not between its elements. So that there are no cold bridges. But in this case, the question arises of its reliable fixation. You can, of course, fix the insulation sheets on the back of the frame. But it will be inconvenient to carry out such an installation with a low base. Access from the back side is difficult, but you need to fix the fixing elements and fill the cracks with construction foam.

The cracks between the sheets of insulation located behind the frame were filled with construction foam. The frame for light siding was assembled from metal profiles for drywall

And, most likely, in locations steel piles the thermal insulation will not fit or its layer will be thinner. These are the disadvantages of this method. Pros: You can use any insulation, in particular inexpensive and easy-to-cut foam of the lowest density. Due to the low price, you can increase its thickness. And the screw piles can be additionally insulated from three sides from the inside of the subfloor.

In the photo, the finishing panels are attached to the plinth sheathing frame, and a roll of insulation made of expanded polyethylene is located behind. Attach it with a stapler to the wooden elements from the inside

Installation of insulation in front of the sheathing frame

Another option for insulating the pile foundation is to first fix the insulation on the frame, and then on top of it - the sheathing. The advantage of this method is the convenience of work. With due diligence, the fixing of the insulation will be as reliable as possible. It is not difficult to seal all existing cracks with construction foam.
If, before installing the sheets of thermal insulation on the frame, fasten a steel fine mesh mesh, the thermal insulation will be reliably protected from rodents, even if they penetrate into the subfloor. As a heater, you will have to use a fairly rigid material, extruded polystyrene foam (EPS) is ideal. The sheathing is fixed on top of the insulation sheets.

The option, when first a heater is attached to the frame, and already a cladding on it, is preferable from the point of view of thermal insulation. There are no cold bridges

But EPS can be finished in other ways. The first, cheap option: plaster with a thin layer of facade plaster on a polymer mesh. The second method is more expensive, but for many it is more beautiful and unambiguously more prestigious: to cover the thermal insulation boards with light facade tiles that imitate brick.

If the thermal insulation and plinth plating protrude beyond the walls of the first floor, they must be protected from above from precipitation by low tide

We talked only about the most available methods of thermal insulation of the basement subfloor on screw piles. There are other methods, for example, cladding with double heat-insulated finishing panels or the installation of a basement wall made of polystyrene blocks of the system " Warm house". But, no matter what technical solutions for the construction and arrangement of your own home you decide to use, we recommend before starting construction works consult with experts on all important issues.

A feature of the pile-screw foundation is the formation of a free, unheated space between the floor and the ground surface. Consequently, it becomes necessary to perform thermal insulation of the base, which can be performed different ways and materials.

The need to insulate the pile-screw foundation

It is imperative to perform thermal insulation of the screw base, for this there are a number of good reasons:

First, the floor in the house will be warmer.
Secondly, the communications under the floor will be protected from freezing.
Thirdly, the pick-up will prevent precipitation from entering under the structure.
Fourth, wooden house with a fitted plinth has a more attractive and complete appearance.

Materials for insulation of the screw foundation

It is quite possible to carry out thermal insulation of the foundation on screw piles with your own hands, the main thing is to choose the right material. Due to the large assortment of products for thermal insulation, problems with the choice of insulation for the basement should not arise.

It is recommended to choose the following options from the whole variety of thermal insulation materials for the protection of the screw foundation:

Liquid polyurethane foam. To use this material, it is necessary to create a crate, placing the boards very close so that there are no gaps. Thermal insulation is applied by spray from cylinders using special equipment. When the foam solidifies, a continuous coating forms on the surface, which does not form cold bridges.
Extruded polystyrene foam. The material is characterized by high thermal insulation properties, good moisture resistance and reasonable cost. The combination of these characteristics gives EPPS a great advantage over other options for thermal insulation materials. Fastening of the insulation can be carried out on a sparse crate or on a solid base.
Facade thermal panels. This option can be called the most profitable of all modern materials that can be used to insulate a screw foundation. wooden house... The advantage of thermal panels lies in the combination of heat-insulating and finishing materials, however, in this regard, the cost of this type of insulation increases.
Foam glass blocks.
Brickwork is one of the most effective and at the same time expensive options (read more about). If you masonry with ordinary bricks, then you will need an additional plinth cladding. The use of facing bricks avoids the finishing step and slightly reduces costs. However, it should be understood that the pile foundation is most often erected on weak unstable soils, which can cause the destruction of brickwork.

It is not recommended to use polystyrene foam for thermal insulation of the screw foundation of a wooden house. The structure of the material promotes the accumulation of moisture between the styrene balls, which, when frozen, exerts high pressure on the particles of the material. This causes the destruction of the foam at low air temperatures.

Do-it-yourself screw foundation insulation

Insulated brick base

The insulation technology is as follows:

Under the grillage around the perimeter of a wooden house, they dig a trench slightly larger than the size of a brick and a depth of up to 30 cm.The bottom of the trench is compacted and poured with concrete mortar (we have already considered it earlier). Additionally, to strengthen the base, you can lay several rods of reinforcement with a diameter of 10-12 mm. The structure is left until the concrete has completely hardened. The result is a kind of foundation for a brick base.
After the concrete has set the required strength, they begin to lay the bricks. The construction of a brick basement is carried out in small areas. In this case, you can additionally insulate the inner wall of the basement.
The final stage is the decorative finish of the brick base. For this purpose, different materials can be used, which simultaneously decorate and protect the free space between the supports of the screw foundation.

Insulation of the screw foundation using decorative panels

It is much easier to mount panels than to make brickwork, however, despite the simple work, the correct arrangement allows you to get a reliable and durable structure. Before starting work, it will be useful to read,.

Thermal insulation of the screw foundation of a wooden house using decorative panels is performed according to a certain scheme:

Pile waterproofing

At the first stage, the foundation screw supports are waterproofed. Regardless of the material of manufacture, all piles need protection, in particular, we are talking about protection from the aggressive effects of moisture. For metal screw piles, a special primer or bitumen mastic is used, in any case, the protective agent is applied to all open areas of the structure. The waterproofing layer must dry completely, for this it is enough to wait about a week.

Blind area manufacturing

Further actions involve the manufacture of a blind area around the perimeter of a wooden house (find out more information about). In this case, the bottom part of the false base will touch the blind area, and not the freezing soil. Arrangement of the blind area is performed as follows:

Soil is removed along the perimeter of the building to a depth of 0.4 meters, the width of the recess can reach 1 meter.
A layer of sand with a height of about 0.2 meters is poured onto the bottom of the trench and carefully tamped.
The next layer is crushed stone, its height can be about 5 cm. Crushed stone is also well leveled and tamped.
Next, lay the waterproofing material and thermal insulation.
Drainage is arranged along the outer edge of the blind area.
Work with this structure will continue after the basement of the foundation is insulated.

Manufacturing of lathing

Next, you need to create a supporting structure, on which the decorative panel will be attached in the future. For this, metal guides are welded to the trunks of the screw supports, which are pre-protected from moisture. The number of profiles depends on the height of the screw foundation, but in most cases their number is limited to three pieces. Wooden blocks pretreated with antiseptic compounds can be used as frame guides. For fastening wooden elements to the piles, metal plates with bolt holes are welded.

Warming

At the next stage, a small groove is made around the perimeter of the frame, removing the soil by about 10 cm. More than half of the resulting depression is covered with expanded clay sand, the low thermal conductivity of which will prevent freezing of the hinged structure in the cold season.

Next, the plates of suitable thermal insulation material are installed and fixed. Most often, the consumer prefers penoplex or extruded polystyrene foam. The thickness of the insulation is selected so that the material does not protrude beyond the grillage. Otherwise, fixing the decorative panel can cause certain difficulties. Installation of a heat-insulating layer depends on the type of insulation.

Now you need to fill the blind area with a concrete mixture and wait for it to solidify completely.

Installation of decorative panels

The next step is the installation of the decorative panel. Its upper edge should be glued to the grillage using a special adhesive for secure fixation. The lower part should be immersed in a groove with a layer of expanded clay sand.

In the finished pick-up of the screw foundation of a wooden house in mandatory make ventilation holes that will provide an appropriate level of humidity in the space under the house on a screw foundation. In this case, the risk of mold and rot is reduced, therefore, the service life of the entire structure is increased.

Do not forget about additional structural elements, therefore, at the end, ebb and corners are installed.

The process of insulating the screw foundation of a wooden house is not particularly difficult. The main condition is compliance with the recommendations of experienced builders. With the correct installation of the frame and the location of the thermal insulation material, you can independently make a reliable and durable structure.