The foundation is the foundation of the house, the stability of the entire structure depends on its strength and reliability. For a long time to keep it from the effects of the external environment will allow warming in parallel with waterproofing. The available technology for installing heat-insulating materials allows you to do the work yourself.
A concrete or pile foundation is regularly exposed to moisture, low temperatures, dynamic loads of moving soil. Through it, the cold enters the basement and inside the house. External insulation of the foundation has advantages over internal:
- Eliminates the formation of condensation on the walls.
- The surface of the foundation is protected from moisture and heaving soil.
- External thermal insulation allows you to maintain a positive temperature in the basement and prevents the walls from freezing.
- The waterproofing layer protects the base from the penetration of groundwater.
- House heating costs are reduced.
Foundation insulation materials
Outdoor work requires special properties and characteristics from heat-insulating materials:
- moisture resistance;
- durability;
- low thermal conductivity;
- strength.
You can insulate the foundation of the house from the outside with polystyrene foam, extruded polystyrene foam, polyurethane foam and expanded clay.
Polyfoam - the material is popular for thermal insulation of the foundation at the initial stage of construction and when facing the finished building. Among its advantages: durability, low cost, moisture resistance, high degree of thermal insulation. The plates are easily fixed with a special glue, so installation is easy to do by hand.
Extruded polystyrene foam does not absorb moisture and is not afraid of frost, it is used in any climate. It is stronger than polystyrene, does not crumble when cutting, has a groove for a tight fit. A 5 cm thick slab is enough to provide effective thermal insulation. Expanded polystyrene is durable, resistant to external stress, and is not afraid of rodents.
Polyurethane foam is a two-component sprayed composition with high thermal insulation qualities. It creates a monolithic surface without joints and cold bridges. Special equipment is used to apply the mixture. Excellent moisture resistance does not require additional waterproofing of the base. Polyurethane foam is applied to any type of surface and creates a protective barrier for 30 years. The composition decomposes under the influence of UV rays, so it must be covered from radiation. The disadvantage of insulation is the high cost.
Expanded clay is an inexpensive bulk insulation that has been used for a long time to insulate the base. With all the positive properties, the material is sensitive to moisture, so careful waterproofing will be required. Unlike synthetic slabs 5-10 cm thick, expanded clay is poured into a trench up to 50 cm wide.
Exterior insulation technology with expanded polystyrene
- A trench is dug along the perimeter of the building to the depth of the base, its width is from 0.5 to 1 meter.
- The surface of the foundation is cleaned and inspected, the detected cracks are covered with cement mortar.
- The foundation is being waterproofed. For this, penetrating insulation, bituminous mastic and welded roll coating can be used. Liquid rubber is applied to the surface with a spatula, the rolled material is heated by a burner and glued to the foundation.
- For thermal insulation, foam or expanded polystyrene plates 5 cm thick are used. They are fixed on the waterproofing layer with mastic or polyurethane glue. Insulation cannot be attached to hot bitumen or solvents can be used as part of the adhesive. In order not to damage the tightness of the layer that protects against moisture, the plates are not additionally fixed with plastic dowels.
- The first row of polystyrene is laid from the corner of the house, the second and the following are mounted with an offset. The joints of the plates are closed with mounting foam. The thickness of the wall insulation is twice the size of the material for thermal insulation of the base, this forms a drip that protects the foundation from precipitation.
- The outer part of expanded polystyrene is covered with a layer of roofing material and geotextile. You can finish it with the glue used for fixing and the reinforcing mesh recessed into it.
- After the end of the thermal insulation, sand is poured into the bottom of the trench with a layer of 15-20 cm and gravel up to 50 cm, the excavated soil is poured to the top.
The described technology is the best option for thermal insulation of a strip foundation.
Device blind area for soil insulation
To prevent freezing of the soil near the house, a do-it-yourself formwork is installed for mounting a concrete blind area.
- A trench is dug from 60 to 100 cm wide and 15-20 cm deep.
- A layer of sand of 10-15 cm is poured on the bottom and rammed.
- Styrofoam boards are placed on top.
- The insulation is covered with a waterproofing sheet that extends 15 cm onto the plinth.
- The surface of the film is covered with a metal reinforcing mesh.
- The formwork from the boards is installed with a slope, at the house its height is 8-10 cm, and drops to the edge up to 5 cm.
- Concrete is poured and leveled.
- The junction of the wall and the blind area is closed with a second layer of basement insulation.
The use of expanded clay for thermal insulation
Warming with bulk material begins with earthworks. A trench is being prepared with a depth of at least 1 m and a width of up to 1.5 m. The base is waterproofed with bituminous mastic or liquid rubber. The surface of the trench is covered with plastic wrap or roofing felt, the ends of the canvas are brought up. Expanded clay is poured inside, insulation is wrapped on its surface. A concrete blind area is made over the trench, having a slope from the wall to the edge.
Spraying polyurethane foam on the foundation
The synthetic composition is suitable for warming any type of foundation: shallow, monolithic and tape. Polyurethane foam is applied to the surface in several layers until it reaches a thickness of 5 cm. When working with a toxic substance, a protective suit is required. Coating Benefits:
- lack of joints;
- moisture resistance;
- strength;
- application speed;
- durability.
The finished surface is treated with a special primer and plastered using a reinforcing mesh. After the finish has dried, the trench is covered with soil.
Warming of the columnar foundation
The construction of the base in the form of pillars or piles leaves free space between the soil and the foundation. The implementation of thermal insulation in this case has its own characteristics, it is necessary to make a pick-up.
- A trench 30-40 cm deep is dug between the supports.
- A pillow of crushed stone and sand is poured onto one third of the height.
- Bars are attached to the pillars, between which boards are stuffed. This is the pickup.
- Waterproofing and insulation are laid on the structure of the boards and the grillage. Decorative finishing is in progress.
- The lower part of the building is sprinkled with expanded clay.
Comprehensive insulation of the foundation and soil enhances the effectiveness of external thermal insulation.
The first steps:
- in the geological exploration service, specify the depth of soil freezing in this region. The foundation is insulated up to this mark;
- choose the type of insulation: outside or inside;
- specify the pros and cons of various heaters;
- before installing the heat-insulating layer on the outside of the building, carry out additional work;
- the creation of fences will close the gaps between the pillars of the foundation and prevent various precipitation from getting inside;
- before arranging external thermal insulation, check whether base waterproofing is needed.
Insulation of the foundation from the outside
Most builders believe that thermal insulation from the outside is preferable to warming the base from the inside. Weighty arguments:
- the heat-insulating layer outside retains the strength of concrete;
- regardless of the type of foundation and insulation, the cold does not penetrate inside the house;
- insulation outside the foundation provides reliable protection against moisture;
- temperature fluctuations are well “quenched” by the outer heat-insulating layer.
Internal insulation of the foundation
This method is rarely used. The thermal insulation layer inside has more negative sides than advantages. Study them.
Advantages:
- thermal insulation inside protects the basement walls from condensation;
- in the basement and in the house there will be a comfortable microclimate.
disadvantages much more serious:
- the foundation from the outside is defenseless against the effects of low temperatures;
- temperature drops and heaving of the soil quickly enough lead to deformation and the appearance of cracks in the base.
Foundation insulation materials
Thermal insulation layer can be done from:
- penoplex;
- polystyrene;
- polyurethane foam;
- extruded polystyrene foam.
When choosing a heater pay attention to the following characteristics:
- coefficient of thermal conductivity. The lower it is, the better the material retains heat;
- density. This factor affects the size of the load on the foundation;
- flammability of the material. High flammability class (G1) will provide reliable protection against fire;
- water absorption coefficient. The worse the material absorbs moisture, the less problems with dampness and mold on a wet base.
Do-it-yourself warming of the columnar foundation
Have you decided to carry out the thermal insulation of the base yourself? How to insulate a columnar foundation yourself? To do this, follow the order of the following steps.
Note! The process of warming the foundation of a brick and wooden house is carried out using the same technology.
Pickup device
The fence protects the foundation from precipitation. It plays the role of a plinth. High-quality insulation of the intake will save the house from drafts, provide a good microclimate and the absence of dampness.
Procedure:
- between the pillars, dig a trench with a depth of 20 to 40 cm;
- pour gravel and sand on 1/3;
- fix the bars with grooves for installing boards;
- with a vertical method of fastening the bars, one part is fastened in a trench, the other - in the lower part of the house;
- when the bars are placed horizontally, they are attached directly to the posts;
- insert boards with a thickness of 4 to 6 cm into the grooves of the bars and fasten them well;
- sprinkle with expanded clay the finished pick-up from the inside;
- now you can proceed to the device of the heat-insulating layer.
Foam base insulation
Any home craftsman can handle this job.:
- thoroughly clean the surface intended for insulation;
- seal all cracks and eliminate irregularities;
- start working from the bottom up;
- apply a suitable adhesive to the foam boards;
- glue the sheets to the base and fix with special plastic dowels;
- the next layer is a reinforcing mesh;
- further - putty;
- the last layer is the finishing putty.
Insulation with extruded polystyrene foam
This material is often used for arranging a heat-insulating layer. Expanded polystyrene prevents the appearance of dampness and the development of fungi. Retains heat well. Sheets are easily mounted using a special adhesive composition.
Installation is carried out without any difficulties:
- the first layer is waterproofing;
- foam polystyrene plates begin to fasten from the bottom, moving up;
- if the waterproofing is made of bituminous rolled material, simply heat the bitumen to 55 degrees, attach the plate and press it well;
- with other types of waterproofing substrate, the insulation is attached with a special mastic. It is applied to polystyrene foam in the form of strips;
- attach the plates to the waterproofing and press.
Thermal insulation of the foundation with polyurethane foam
A new word in construction practice. The material quickly gained popularity.
Durable, environmentally friendly, durable, fireproof polymer is applied from a special blowing machine. Just 5 cm of polyurethane foam - and your foundation is well insulated. The undoubted advantage is the high speed of work.
If you can rent a blowing machine - do the work yourself:
- clean the foundation from dust, debris, earth particles;
- apply insulation directly to the base. Foam will fill all the cracks, bumps. No voids or air pockets;
- adhesion is excellent. The material sets quickly;
- the result is a high-strength synthetic board.
Note! The material does not absorb moisture. For reliability, experts recommend that additionally, on top of the insulation layer, perform waterproofing from a water-repellent material: liquid rubber, polyurea and others.
If nothing works out with the rental of a machine for applying polyurethane foam, you will have to call the specialists of a construction company.
Insulation of the foundation with foam
Penoplex is made using a special technology from extruded polystyrene foam. The material has excellent performance:
- one of the most heat-resistant polymers;
- durable;
- durable;
- safe for humans;
- installation is quick and easy;
- a wide range of polymer plates (thickness from 20 to 100 mm) allows you to choose the right option and not overpay for the extra layer thickness.
Plate size: 60x240 and 60x120mm. There are three categories of insulation with different densities.
Note! The polymer is fairly flammable. Perhaps this is its only drawback. You can apply a layer of flame retardant. At the same time, environmental performance will decrease.
Procedure:
- cover the entire surface with a special adhesive mastic: from the sole to the grillage;
- to the zero level, simply press the plates against the wall;
- between the zero level and the grillage, additionally fix the penoplex with dowels-umbrellas;
- to attach heat-resistant dowels, drill holes in the base;
- most panels fit well into the groove. Check all seams. To be sure, insulate them with mounting foam.
Insulate the columnar foundation according to the technology corresponding to each type of heat-insulating material. Well-insulated base will serve as the basis for warmth and a comfortable microclimate throughout the house.
Foreword. How and with what to insulate the columnar foundation of the house with your own hands? Do I need to insulate the columnar foundation of the bath and the house? Proper insulation of the foundation pillars will help save heat and protect the structure from early destruction. We will consider in the article how to independently insulate the structure, what materials to use for thermal insulation, and also show a video on this topic at the end of the article.
The columnar foundation of a wooden house is used on complex and heaving soils. The pillars are placed in the corners of the house and at the intersection of the internal walls, as well as along the perimeter of the building through 1.5–2.5 meters and below the depth of soil freezing on the site. The pillars rise above the ground, usually by 0.25-1 meters. For structural rigidity, a strip foundation is poured along the top of the pillars or strapping beams are placed.
Do I need to insulate the columnar foundation of the house
A photo. Scheme of the device of the pillar foundation
If the columnar foundation of a wooden house is made of rubble or concrete, then after removing the formwork, the surface of the pillars is insulated with bituminous mastic in two layers. Instead of bitumen, penetron penetrating waterproofing can be used, which penetrates deep into the micropores of concrete. It is also necessary to process and independently insulate the strip foundation or strapping beams from moisture rising from the ground.
Self-insulation of the columnar foundation of the house outside is carried out using extruded polystyrene foam (foam or technoplex). You can also use a cheaper, but less durable plate material - polystyrene foam. In order to choose the right materials for thermal insulation, it is necessary to consider the most popular plate heaters, the technical characteristics of foam plastic and foam plastic.
How to insulate the columnar foundation of the house from the outside
A photo. Insulation between the ground and the wall of the house
Styrofoam suitable for both external and internal insulation of the columnar foundation of a bathhouse and a house. Many developers choose expanded polystyrene because of its low cost, but it is better to replace the foam with a more durable extruded polystyrene foam. Penoplex is a more expensive material, but it has high mechanical strength, thermal insulation boards are not afraid of high humidity and rodents, which is an advantage.
Penoplex, like other extruded styrenes (technoplex, ursa xps, etc.) is characterized by high strength, low vapor permeability and durability. The insulation is produced in plates with a thickness of 20 to 100 mm, the material is resistant to moisture, microorganisms, insects and rodents do not start in it. Penoplex is used today not only for thermal insulation of the foundation, but also for warming the blind area of the house around the perimeter.
Mineral wool, as well as basalt wool is supplied in rolls and slabs of various thicknesses. Despite the low thermal conductivity of URSA mineral wool, like mineral thermal insulation from other manufacturers, it has high water absorption. The use of mineral wool as a thermal insulation of the foundations of houses is not recommended. You should carefully protect the material from moisture, find out which side to lay the vapor barrier on the mineral wool on our website, so as not to make a mistake when waterproofing.
Expanded clay is an inexpensive insulation for a columnar foundation and is a time-tested material. Expanded clay for thermal insulation of the pillar foundation of a house or bath is used by developers as follows: on the inside of the foundation, formwork is erected from boards of 30-40 cm and expanded clay is poured into it. You can also fill the foundation inside the house with soil or the same expanded clay.
Scheme of insulation of the pillar foundation of the house
Independent thermal insulation of a columnar foundation with polystyrene foam or technoplex is similar to the insulation of a proper screw foundation, since the structures are largely similar. All work is carried out immediately after the waterproofing of the structure with the capture of the grillage (strapping beams) and part of the facade of the house by 25–0 cm. The foundation pillars are sheathed with bars and boards to the full depth to create a frame for thermal insulation.
How to insulate a columnar foundation with your own hands
How to insulate the columnar foundation of the house from the outside? To insulate the columnar foundation with foam, the sheets are fastened with dowels or fastened with glue for polystyrene foam to the prepared basement crate. Penoplex is durable, has high mechanical strength and retains its properties in wet soil. The seams between the thermal insulation plates are carefully sealed with mounting foam.
If there is no plinth between the foundation pillars, then only the grillage is insulated (insulation of the wooden floor from below), and a moisture-resistant slab insulation is laid on the ground inside the house. This work can be done independently, for this, an insulated floor made of mineral wool is installed, a similar technology is used when insulating the floor in an apartment on the ground floor or in the basement of a private house.
Video. How to insulate a columnar foundation from the outside
Insulation of the columnar foundation provides for a number of additional works on the installation of barrier fences, the purpose of which is to close the gaps between the pillars and protect them from the effects of precipitation.
Foundation insulation is an important component of foundation work. When constructing one or another type of foundation, this problem is solved in its own way and has its own initial data. Therefore, the insulation of the foundation must be carried out in the most efficient and economical way.
A columnar foundation is a complex of pillars dug in at all available corners of the building and in places of significant load under the bearing parts of the object. In order to ensure the coordinated functioning of the pillars as one structure and increase their stability in order to prevent horizontal tilt and overturning and to support the basement, the pillars are connected with a grillage (rand beams, strapping beams).
For a complete vision of the picture, criteria should be considered that indicate that it is better to build a columnar foundation:
- buildings are erected without basements, having walls with low weight (panel, frame, wooden);
- when a deep laying is necessary (20-30 centimeters below the seasonal freezing of the soil, 1.6-2.0 meters) under the brick material of the walls and the installation of a tape-type foundation is uneconomical;
- when the shrinkage of the foundation is much lower than this parameter for the tape;
- if the soils undergo a significant change under the influence of the forces of frost heaving: the pillars are less than others exposed to this effect.
Column foundation: device
Preparatory stage: clearing the construction area. The vegetation layer is cut off, a horizontal layout of the site is made. Irregularities are removed, earth is poured into the pits. Evenness is checked with a level.
Breakdown of the territory for the foundation: the scheme is transferred from drawings to nature by fixing the axes and dimensions of the object. Deepening the foundation from the zero mark of the house.
Digging holes for poles (20-30 cm below the laying):
- pits up to 1 meter deep are dug with vertical walls and without fasteners;
- more than 1 meter in depth - slopes are made on the walls, reinforced with boards and struts.
- Formwork installation. It is better to give preference to wooden materials than metal ones. This step can be omitted if the surface of the pits is dry and not crumbling.
- Installation of vertical reinforcement (d = 10-12 mm) on poles with clamps.
- Delivery and placement of concrete.
- The grillage device in the form of a monolithic or prefabricated reinforced concrete end beam.
- Pickup installation.
Its purpose is to insulate the space under the floor and protect it from dirt and debris.
Thermal insulation of the columnar foundation
It is possible to insulate a columnar foundation with the help of a pick-up and a number of other additional insulation works. Zabirka is a fencing wall located between the pillars. It can be built from various materials: wooden boards, bricks, stone. It is necessary to describe in more detail each type of pick-up from a particular material.
The degree of warmth and dryness of the floors in the house, its protection from the winds will depend on how technologically correctly the pick-up is performed.
Manufacturing technology of a wooden fence
There are several ways to insulate a columnar foundation with a wooden fence:
- Installation of boards vertically.
- Placement of boards in a horizontal direction.
- Making a fence from beams or logs.
It is possible to insulate a columnar foundation by mounting boards vertically in this way: in a trench 200-400 millimeters deep, dug between the pillars, fine gravel and sand are poured into about one third of it. A log with a groove is laid in the trench and a similar log is fixed to the grillage. Boards are alternately inserted into the grooves between the logs in a vertical position.
To make a fence with horizontal placement of boards and insulate the columnar foundation, you need to: dig a trench between the pillars like the previous option. Attach logs or beams with a groove to the posts. Boards (40-60 millimeters in thickness) are installed in the groove so that the very first bottom board is laid on the trench pillow, and all other boards are laid on top of it.
From the inside, a wooden fence made of boards is sprinkled with expanded clay, and it is insulated.
To insulate the foundation with a log fence, logs are laid horizontally between the posts, as in the construction of a log house.
It is possible to insulate the foundation with the help of brick and stone masonry. If a fence is being constructed from such materials, then you need to dig a trench, which will serve as a sole for laying brick or stone. The brick is laid on a concrete screed, fixed with reinforcement. The thickness of the stone walls of the fence is made within 30 millimeters, the brick is placed in 1-1.5 pieces. In order to avoid the occurrence of cracks and gaps between the pillars and the masonry, strong adhesion is not necessary.
In buildings where high poles are installed (from 0.7 meters), pickups are made of sheet insulation material. To insulate the foundation, a frame profile metal structure of the desired section is first attached to the pillars. Outside, sheets of corrugated board are hung on it, and from the inside they are insulated with sheets of foam (expanded polystyrene). The gap between the insulation sheets and the ground is sprinkled with heat-insulating backfill.
It is possible to insulate the finished construction of the intake for the foundation around the entire perimeter with plates of extruded polystyrene foam, which are attached outside the intake with special glue. At the same time, the foam boards are tightly adjacent to each other so that there are no gaps between them. Penoplex insulation is considered the most effective method that does not require waterproofing. However, in order to ensure reliable protection of the basement from moisture, it is desirable to provide the foundation structure with a waterproofing coating.
The heat loss of a building through the floor can reach 20% and depends on how well the insulation of both the floor itself and the entire base of the house is done. On normal soils, for the sake of economy, columnar foundations are often arranged. This type of foundation costs about 1.5-2 times cheaper than a strip one. With correct calculations, such a foundation is not inferior to a tape foundation in terms of strength and reliability, and sometimes even surpasses it.
Why insulate a columnar foundation?
Insulation of the columnar foundation has two goals. The first and most important goal is to protect the foundation itself from thermodynamic damage. The second is to reduce the overall heat loss of the house.
There is no universal formula for foundation insulation. In each case, the methods of insulation are selected individually. This is the work of an architect. Therefore, this article does not give step-by-step instructions for insulating a columnar foundation, but names the main factors influencing the decision.
First of all, it is worth dwelling in more detail on the question: do you need insulation for a columnar foundation at all? Surely there will be builders who are inclined to believe that the foundation may not be insulated. However, when such an opinion is expressed, it should be said what kind of foundation is being discussed, or rather, about the foundation of which house. If it is, then the answer is obvious.
So, back to our first question: why insulate a columnar foundation? When talking about the insulation of a columnar foundation, they mean the insulation of the resulting underground space. If left unprotected, the ground under the building will freeze. In the protected underground, even in the most severe winters, the ground temperature does not fall below 0°C. This has a positive effect not only on the energy efficiency of the cottage, but also on the foundation itself, because the soil at positive temperatures does not swell and does not squeeze out the columns.
By its design, the columnar foundation is very similar to the pile foundation. The difference is only in the depth of the supports. Piles, as a rule, are lowered to a great depth. The columns are installed on a sand cushion, which is located below the depth of freezing of the soil. Between the columns, as well as between the piles, there is a certain distance. Usually the posts are laid at the corners and intersection points of the walls, as well as at intermediate sections if the wall is heavy or long.
When the columnar foundation is ready and the builders move on to building the box of the house, the need to fill the space between the columns is visible. A house without such filling looks unfinished. In addition, garbage collects under it, the ground freezes, and the walking wind cools the floor, constantly taking heat away.
It is obvious that the insulation of the columnar foundation is simply necessary. Especially today, when energy efficiency is becoming the main condition of construction.
When is it worth doing the insulation of the columnar foundation
Under the insulation of the columnar foundation is meant both insulation using heat-insulating materials, and simple sealing of spans between the columns, i.e. pickup device. In the vast majority of cases, a house on a columnar foundation also has a fence. It is performed in different ways, depending on the material of the columns; their heights above the ground; from architectural preferences, after all.
An example of a pickup device.
Unfortunately, it should be noted that a modern energy-efficient house cannot be built on a columnar foundation. Such houses are placed on monolithic slabs, completely isolated from the ground with a thick layer of rigid insulation. All other types of foundations (including columnar ones) suggest the so-called cold bridges. If it were technically possible to establish an effective thermal break between the support and the wall, then the columnar foundation would be one of the most economical and energy efficient at the same time. However, none of the existing insulation today is able to withstand concentrated compressive loads, such a force exerted by the weight of the building.
Now let's make a small but important digression regarding the financial side. It is impossible to reduce the construction budget and increase the energy efficiency of the building at the same time. These articles are directly opposite in essence. Theoretically, it is possible to insulate all the enclosing structures of the house so qualitatively that several hundred watts will be enough for heating. But will there be any material benefit from this? Warming also costs money. In addition, it has its own lifespan. If a the payback period of insulation is equal to the period of its operation, then it is impossible to call such insulation profitable. Warming is considered appropriate if it pays off at least half of the time allotted to it.
However, there is another opinion. Some experts consider insulation as a kind of investment project. It is believed that young and energetic people have the opportunity to invest in serious insulation, and this will insure them against serious operating costs in old age, when they can no longer earn much.
Economists would consider this not the most profitable investment, because the funds can be put in the bank, and the interest will probably be enough to pay energy bills. Moreover, it will already be the so-called compound interest.
If you put $1,000 in a bank at 10% per annum, then in 20 years your account will have $6,727. This is taking into account the fact that interest on the deposit will be accrued on interest and on the condition that the deposit will not be withdrawn. And that's just a thousand. And when insulating a house with a layer of 10-15 cm, ten thousand may be needed. Accordingly, with the contribution of such an amount, the profit will increase by an order of magnitude.
In general, everything must be considered. True, there is one unknown in this task - the cost of energy carriers in the future. In addition, money depreciates, life becomes more expensive, there is no stability. So people come to the conclusion that it is better to warm up now than to pay fabulous bills all your life and at the same time heat the atmosphere for your hard-earned money.
How to insulate a columnar foundation
We return to the main topic. It is unlikely that anyone today will consider it a good idea to leave the columnar foundation completely open. Usually, at a minimum, a cold pickup is performed.
Zabirka- this is a fence that fills the gap between the corner supports of the columnar foundation. The construction standards describe in sufficient detail the design of the pick-up. In this case, first of all, they are guided by SNiP 2.02.01-83.
For the construction of the fence, various building materials are used. It can be brick, stone, cinder blocks, boards or beams, sheet materials (plywood, OSB). It is not recommended to use cellular concrete blocks and other materials with high water absorption for the construction of the intake. It is not difficult to guess why: the pick-up is subject to moisture (capillary, rain / snow). Since the pickup does not carry any loads other than from itself, there are no requirements for the strength of its material. The pick-up can be made from lightweight large-format ceramic blocks. Such a pick-up will be both durable and heat-insulating at the same time.
Brick fence. Often the fence is built of brick or stone. In this case, it requires a solid foundation under itself. Under a wooden house, the pick-up is deepened 20-30 cm into the ground. It is recommended to do this, first of all, if the house is built on heaving soils. Narrow trenches are dug under the pick-up, at the bottom of which it is necessary to cast screed on a sand cushion.
Sometimes a stone fence is erected directly on a sand cushion. But on the screed it will still be more correct, since it evenly distributes the load from the masonry. The screed in this case is a guarantee that the stacking masonry will not crack under its own weight.
Insulation of fences and blind areas. Now let's talk about whether it is worth additionally insulating the pick-up. The most authoritative experts strongly recommend doing this. Insulation of a columnar foundation, together with a pick-up, is relatively inexpensive, but provides many advantages. Insulated foundation guarantees a positive temperature in the underground; in addition, the columns themselves in the insulated form will not freeze through. If you also insulate the blind area, then the columns can be laid not to the depth of freezing of the soil, but half as fine. This will make you spend a little on insulation, but will save money on earthworks and on building material itself.
It is best to insulate a columnar foundation outside so that the posts themselves and the pick-up are isolated from the cold. Warming should be done in a continuous contour without breaks. Since both the foundation and the filling are in contact with the ground and are subject to moisture from capillary moisture and precipitation, it is necessary to choose materials with zero water absorption. These include extruded polystyrene foam, foam glass, foam propylene and other closed-cell polymer insulation.
Insulation of the columnar foundation with polystyrene with decorative paneling. The best option both in terms of quality and cost is, perhaps, extruded polystyrene foam (EPS). Unlike conventional foam, XPS does not absorb moisture and therefore does not accumulate it. Ordinary (non-extruded) polystyrene foam has significant water absorption, so it is not the best material for insulating the basement, and even more so the foundation. If you have a question about choosing a heater, the materials of the article can help:.
After the construction of the fence, the columnar foundation looks like a strip foundation. Accordingly, the issue of ventilation of the internal space becomes. As in the case of a strip foundation, you will need products. If the pick-up is constructed of brick or stone, then the air is left in the form of passes.
To protect against rodents and birds, the vents are covered with metal mesh. Air ducts should be located on each side of the base of the house. In brickwork it is more convenient to make square ducts. The recommended size is 10-15 cm. The products are distributed so that they are opposite each other. Their meaning is that the wind blows fresh air into the underground from whichever side it blows. Then "excess" air will come out from the rest of the vents. Thus, ventilation of the underground space is carried out.
Ordinary columnar foundations do not have a grillage in its technical sense. The pick-up is laid only on the outer contour. Inside the perimeter of the house, the columns are not connected by solid walls, so there is no need to make internal ventilation, as is the case with a tape-type foundation.
The number of products theoretically depends on the volume of the underground. If the height of the column above the ground is within 30-40 cm, then one air is enough for 3-4 m horizontally. These figures are taken from practice and they are most likely correct. If you make too many vents or their cross section is too large, then the underground begins to overcool. At the same time, no matter how many vents are made (within reason), the soil under the house will still not freeze. But everything needs a measure.
The lack of products is also bad. The soil contains moisture, and it eventually ends up in the insulated underground. There is no big trouble in this, especially if the posts and the fence are made of high-grade concrete. However, moisture always remains the enemy of any structure. Reinforcement in reinforced concrete columns from moisture strongly corrodes. Rust increases in volume and literally breaks concrete. And the weakening of the support of the building is an unpleasant thing.
Finally. Guided by the considerations expressed in this article, you can independently make decisions when developing the insulation of a columnar foundation. Understanding the principle of foundation insulation, knowledge of heat-insulating materials and makes it possible to find, based on building codes, the best way of thermal insulation.