With this calculator determine the load on the foundation strip and the width of the foundation sole.
- dimensions of vertical and horizontal thermal insulation;
- soil pad thickness.
Initial data:
- As a heat insulator, we accept thermal insulation boards made of extruded polystyrene foam (XPS) grade 35;
- The material for the device of a soil cushion and backfilling of the sinuses of the pit is crushed stone with a density R=2040 kg/m3 and modulus of deformation E=65000 kPa.
- The base soils are represented by silty sands with a density R=1800 kg/m3 (18.0 kN/m3) and deformation modulus E= 18000 kPa.
Calculation sequence:
Step 1. Definition of MI. The specified parameter is found for the construction site (Smolensk) according to the schematic map of IM (see below). MI = 50000 degree hours.
Step 2. Determining the parameters of vertical and horizontal thermal insulation.
In table 1, the frost index IM=50000 degree hours corresponds to the following thermal insulation parameters:
- vertical insulation thickness by=0.06 m;
- thickness of horizontal thermal insulation along the perimeter of the building bh=0.061 m;
- thickness of horizontal thermal insulation at the corners of the building bc=0.075 m;
- skirt width Dh=0.6 m;
- length of sections near the corners of the building Lc=1.5 m.
Step 3. Calculation of the thickness of the soil cushion.
The thickness of the soil cushion for heated buildings with indoor air temperature in winter not lower than 17 ° C is taken to be at least 0.2 m.
Answer. Based on the calculation, we finally accept:
- the thickness of the vertical thermal insulation of the slabs by=0.06 m;
- thickness of horizontal thermal insulation along the perimeter of the building from slabs bh=0.061 m;
- thickness of horizontal insulation at the corners of a slab building bc=0.075 m;
- the width of the thermal insulation skirt Dh=0.6m;
- length of sections near the corners of the building with reinforced thermal insulation Lc=1.5 m;
- the thickness of the soil cushion is 0.2 m.
In this case, the depth of the pit under the TFMS will be: 0.4 m + 0.2 m = 0.6 m.
Frost index on the map
 |
| Fig.1. frost index |
Frost index (MI): the absolute value of negative degree hours of outdoor air with a 1% probability or an event with a probability of once in 100 years.
The frost index with such security is not used in construction practice on the territory of the Russian Federation. Such security is due to high requirements for the durability of foundations. With reduced requirements for the durability of the foundation, it is possible to take the value of the MI security of 2% (the occurrence of an event with a probability of once every 50 years).
The required IM values are obtained by special calculations. For approximate calculations, the value of MI can be taken from the schematic map shown on Rice. 1 Watch!- all polls
The thermal insulation of a dwelling must begin with the foundation, and the best material for this is polystyrene foam. Insulation of the foundation with polystyrene foam is a 100% proven option, + the video will help you master the technology. And although this method is not the cheapest, it is very effective, and also quite simple to perform.
Insulation of the foundation with polystyrene foam
Insulation characteristics
Sheet expanded polystyrene
Sheet expanded polystyrene has a large number of positive properties:
In addition, this material is easy to install and lasts about 40 years if the thermal insulation is made in accordance with all the rules. Expanded polystyrene also has disadvantages:
Solvent-based adhesives and hot mastic must not be used to fasten polystyrene foam sheets. To protect the insulation from damage, it must be transported and unloaded carefully, not thrown from a height, and after laying it must be covered with exterior finishes - tiles, siding, plaster, or at least cement mortar.
| Specifications of polystyrene sheet | Index |
|---|---|
| Temperature range of operation of sheets that do not experience mechanical loads (C °) | from -18 to +60 |
| Density (kg/m3) | 1040 — 1060 |
| Hardness (MPa) | 120 — 150 |
| Softening point (according to Vicat) in air (С°) | 85 |
| Softening point (according to Vicat) in a liquid medium (С °) | 70 |
| Tensile strength, MPa (kgf/cm2), not less than for sheets with nominal thickness up to 3.75 mm inclusive | 17,7 (180) |
| Tensile strength, MPa (kgf/cm2), not less than for sheets with nominal thickness over 3.75 mm | 16,7 (170) |
Preparatory stage
Expanded polystyrene PSB-S
First you need to calculate how many insulation boards you need for the foundation. The dimensions of a standard expanded polystyrene plate are 600x1200 mm, thickness is from 20 to 100 mm. For the foundation of a residential building, 50 mm thick slabs are usually used, laying them in two layers. To find out how many plates are needed, the total length of the foundation is multiplied by its height and divided by 0.72 - the area of \u200b\u200bone sheet of expanded polystyrene.
For example, if a foundation 2 m high is insulated in a house 10x8 m, the area of \u200b\u200bthermal insulation is 72 squares. Dividing it by 0.72, we get the number of sheets - 100 pieces. Since the insulation will be carried out in two layers, it is necessary to buy 200 plates with a thickness of 50 mm.
This, however, is a very average calculation, based on the fact that the thickness of the insulation will be exactly 100 mm. But this value can be more - it all depends on the climatic conditions of the region, and on the foundation material, and on the type of insulation.
There is a special system for calculating the thickness, for which you need to know the R indicator - this is the constant value of the required heat transfer resistance established by SNiP for each region. It can be clarified in the local department of architecture, or taken from the proposed table:
| City (region) | R is the required heat transfer resistance m2×°K/W |
|---|---|
| Moscow | 3.28 |
| Krasnodar | 2.44 |
| Sochi | 1.79 |
| Rostov-on-Don | 2.75 |
| St. Petersburg | 3.23 |
| Krasnoyarsk | 4.84 |
| Voronezh | 3.12 |
| Yakutsk | 5.28 |
| Irkutsk | 4.05 |
| Volgograd | 2.91 |
| Astrakhan | 2.76 |
| Yekaterinburg | 3.65 |
| Nizhny Novgorod | 3.36 |
| Vladivostok | 3.25 |
| Magadan | 4.33 |
| Chelyabinsk | 3.64 |
| Tver | 3.31 |
| Novosibirsk | 3.93 |
| Samara | 3.33 |
| Permian | 3.64 |
| Ufa | 3.48 |
| Kazan | 3.45 |
| Omsk | 3.82 |
In order not to bother the reader with calculation formulas, a special calculator is placed below, which will allow you to quickly and accurately find the required thickness of thermal insulation. The result obtained is rounded up, leading to the standard thickness of the panels of the selected insulation:
In addition to polystyrene foam, you will need:
When all the materials are prepared, a trench is dug around the perimeter of the foundation. You need to dig to the level of freezing, that is, to a depth of 1.5-2 m. In order to make it convenient to work in a trench, its width should be 0.8-1 m. Of course, excavation is done exclusively by hand, since equipment can damage the foundation. The walls of the base must be thoroughly cleaned of the ground, irregularities and cracks should be repaired with mortar.
Foundation insulation technology
House insulation
The process of insulation consists of the following stages: waterproofing the surface, fixing polystyrene foam, exterior finishing of the foundation. After excavating the earth, you need to wait until the base dries well, and only then proceed to insulate the walls.
Foundation waterproofing with liquid rubber
Coating waterproofing with a layer of 4 mm is applied to dry, even walls of the foundation. Mastic should be used without organic solvents, preferably on a polymer or water basis. The mixture is applied with a roller, trying to fill the pores and small cracks in the concrete well. You can use only roofing material for waterproofing or combine both materials: apply roofing material over the mastic and glue the joints with the same mixture.
Foundation waterproofing
Gluing waterproofing
Surface waterproofing
The moisture-proof layer must completely cover the entire surface of the base and the plinth and have no gaps.
When the mastic dries, you can proceed to the main stage. They take the first sheet of insulation and apply glue on the back side either in longitudinal stripes or pointwise, the main thing is that the glue is in the center of the sheet and along the edges. 1-2 minutes after application, the sheet is applied to the foundation, its position is checked by level and strongly pressed. The slabs are attached to the foundation only with glue so as not to violate the integrity of the base, and on the plinth the slabs are additionally strengthened with fungal dowels and.
Applying glue to polystyrene foam
Spot application of glue
Fungus dowel attachment
Fungus dowel attachment
Fastening polystyrene with dowels
The next sheet must be attached to the side close to the first, so that the joints are as tight as possible. Be sure to control the level of the location of each fragment - this will eliminate the formation of distortions. Laying is carried out from the bottom up, while vertical seams are recommended to be shifted half a sheet to the side. When the first layer is completely fixed, proceed to the second. Everything is repeated in exactly the same way, only the joints of the upper layer should not coincide with the joints of the lower one - the plates must be laid with an offset. In conclusion, they carefully examine the thermal insulation layer and, if cracks are found in the seams, blow them out with foam.
When insulating the basement, the sheets are laid immediately on the glue, and the dowels are used after 2-3 days, when the glue is already dry. Each plate is fixed in the corners and in the center; to save fasteners can be placed at the seams.
Foundation insulation
Foundation insulation
Foundation insulation
Step 3. Plastering the foundation
To protect the styrofoam boards, another layer, such as plaster, is needed. The basement can be covered with siding or lined with porcelain stoneware. First, a fiberglass mesh is fixed over the plates using dowels with large caps. At the joints, it is necessary to lay the reinforcing material with an overlap of 10 cm. It is recommended to stretch the mesh well so that wrinkles do not form, which will lead to cracking of the plaster layer.
Mesh attachment
Plastering on a reinforcing mesh
Surface leveling is carried out with a cement-sand mortar or acrylic adhesive. The first method is much cheaper, and therefore is used more often. The solution is made thick enough and applied with a wide spatula, firmly pressing the mixture into the cells of the grid. The layer of plaster must be of the same thickness over the entire area. The foundation is plastered to the level of backfilling, and the basement is finished a little later.
Plaster consumption
Step 4. Backfilling the foundation
It is impossible to fill up a trench until the plaster dries. First, a 10-cm layer of sand is poured onto the bottom, leveled and rammed, then a gravel cushion 20 cm thick is arranged. You can replace the gravel with expanded clay mixed with sand - this will increase the thermal insulation properties of the base. Next, the trench is covered with soil with mandatory compaction every 25-30 cm. When 40 cm remains to the top of the trench, a blind area should be made around the entire perimeter of the foundation.
Foundation backfill
Step 5. Making a blind area
Making slope markings
A layer of gravel about 10 cm across the width of the trench is poured over the soil, tightly rammed.
Packed gravel
We lay polystyrene foam, reinforcing mesh, install formwork and expansion joints
Filling the pavement with concrete
Ruberoid is spread over the gravel; at the joints, the material is overlapped by 12-15 cm and coated with bitumen. The next layer is expanded polystyrene: the plates are tightly laid in one row along the perimeter of the house. Further around the slabs, formwork is mounted from boards about 10 cm high. For strength, a metal grate with small cells is placed in the formwork. A thick cement mortar is prepared and poured so that a slight slope forms from the wall. The inclined surface facilitates the outflow of melt and rain water.
If desired, the blind area can be decorated with paving slabs
Step 6. Finishing the plinth
As soon as the blind area dries, you can begin the exterior decoration of the basement. Since this area rises above the ground and is clearly visible, the finish must be very neat and attractive. The easiest way is to plaster the surface and cover it with facade paint. Before applying the plaster, a reinforcing mesh is fixed on the polystyrene boards. If desired, you can give the surface a three-dimensional texture, or vice versa, make the wall absolutely smooth.
Finishing the plinth with stone
Plinth paneling
Most often, the plinth is finished with decorative stone or tile. To do this, the plastered surface is primed, dried, and then the finishing material is attached to the glue.
It is very important to seal the seams between the fragments so that moisture does not penetrate through them to the insulation.
On this, the thermal insulation of the foundation is considered completed. If all conditions are met, it will not take a very long time to change the insulation.
Video - Insulation of the foundation with polystyrene foam for a 100% proven option + video
When constructing a foundation, special attention should be paid to the issue of its thermal insulation, especially in regions with a harsh climate and deeply freezing soil.
About 80% of the territory of Russia is located in the zone of heaving soils, which pose a particular danger to foundations.
Heaving soils during seasonal or long-term freezing are able to increase in volume, which is accompanied by a rise in the soil surface. The rise of the soil surface during the winter can reach 0.35 m (15% of the depth of the freezing soil layer), which in some cases leads to deformation of the structure: freezing with the outer surface of the building envelope, the soil is able to lift it due to the tangential forces of frost heaving. When laying foundations above the freezing depth of heaving soils, or if the foundation slab was not insulated during construction in winter, normal frost heaving forces arise under its sole.
Horizontal thermal insulation of the foundation with cutting off the zone of frost heaving, allows you to reduce to zero the risks arising from the rise and thawing of heaving soils.
It has been established that the share of basement and basement foundations accounts for about 10-20% of all heat losses at home.
Insulation of buried structures reduces heat losses, protects the foundation structure from freezing, avoids condensation of water vapor on cold walls (associated with insufficient thermal insulation or ventilation in the room), and prevents dampness and mold development. At the same time, in country houses for summer living, the insulation of foundation and basement walls does not make sense, except when it is necessary to correct design flaws associated with the consequences of frost heaving of soils.
Thermal insulation requirements are not put forward for unheated basements.. However, it is necessary to insulate the walls at least in the basement area so that they do not freeze at the border of the ceiling between the unheated basement and the heated rooms on the first floor.
In addition, thermal insulation protection is an integral element of the waterproofing system: it protects the waterproofing coating from destruction and temperature aging.
Advantages
- eliminates or significantly reduces the impact on the foundation of the forces of frost heaving;
- reduces heat loss and reduces heating costs;
- provides the required and time-constant temperature inside the room;
- prevents formation of condensate on internal surfaces;
- protects waterproofing from mechanical damage;
- contributes to the extension of the durability of waterproofing.
Foundation insulation
Special requirements are imposed on the materials used to insulate the foundation from the outside:
- low water absorption;
- high compressive strength (with low thermal conductivity);
- resistance to aggressive underground waters;
- resistance to decay.
Mineral wool is not suitable due to compressibility when backfilled with soil and high water absorption.
Given the low water absorption (< 5%) and high strength ( 0.4-1.6 MPa), foam glass can be used for external vertical and horizontal thermal insulation. True, this option turns out to be several times more expensive.
Expanded polystyrene (styrofoam)
Low short-term compressive strength (
If ordinary foam is used to insulate foundations from the outside, then it is located under a waterproof layer (: foundation waterproofing - foam plastic - system waterproofing). Otherwise, a few years after installation, the foam will turn into a shapeless pile of balls. The moisture accumulated in the insulation, when frozen, will increase in volume and destroy its structure.
Under conditions of increased loads and humidity, the most optimal heat-insulating material is.
Due to the properties of the feedstock and the closed-cell structure, which makes it difficult for water to penetrate inside, extruded polystyrene foam has excellent technical characteristics and a long service life, which allows it to be used for foundation insulation.
EPPS has almost zero water absorption (no more than 0.4-0.5% by volume for 28 days and for the entire subsequent period of operation), so ground moisture does not accumulate in the thickness of the insulation, does not expand in volume under the influence of temperature changes and does not destroy the structure material throughout its service life (frost resistance more than 1000 freeze-thaw cycles).
Due to their strength, extruded polystyrene foam boards increase the service life of the waterproofing coating, protecting it from mechanical damage and providing a positive temperature regime.
Thus, the insulation of the foundation and basement of the house with extruded polystyrene foam extends the life of the foundation.
Advantages
- stability of thermal insulation properties throughout the entire service life;
- service life of at least 40 years;
- compressive strength is from 20 to 50 t/m 2 ;
- is not a breeding ground for rodents.
Calculation of the thickness of the insulation
The required insulation thickness for the basement wall located above ground level is taken equal to the thickness of the insulation for the outer wall and is calculated by the formula:
The required insulation thickness for a basement wall located below ground level is calculated by the formula:
- δ ut- insulation thickness, m;
- R 0 pref.- reduced resistance to heat transfer of the outer wall, taken depending on the value of the GSOP, m 2 ° C / W;
- δ - thickness of the bearing part of the wall, m;
- λ - coefficient of thermal conductivity of the material of the bearing part of the wall, W / (m ° C);
- λ ut- coefficient of thermal conductivity of the insulation, W / (m ° C).
The required thickness of insulation from extruded polystyrene foam boards in the basement walls for all regional and republican centers of the Russian Federation is shown in the table:
The range of XPS materials includes specially designed thermal insulation boards with milled grooves on the surface. This material, together with a geotextile fabric, successfully works as wall drainage, i.e. it performs three functions: insulation of the foundation, protection of the waterproofing from mechanical damage, and removal of water from the foundation in the drainage system.
How to insulate the foundation?
When insulating the vertical part of the foundation, expanded polystyrene is installed on soil freezing depth determined for each region individually. The effectiveness of insulation with a deeper installation is sharply reduced.
The thickness of the insulation in the corner areas should be increased by 1.5 times, at a distance of at least 1.5 m from the corner in both directions.
Insulation of the foundation from the outside is the most rational, provides a low level of heat loss.
Insulation of the foundation from the outside
Warming the soil around the perimeter of the house under allows you to reduce the depth of freezing along the walls and under the base of the foundation and keep the freezing boundary in a layer of non-porous soil - sand, gravel cushion or backfill soil. At the same time, extruded polystyrene foam must be laid with a predetermined blind area slope of ≥ 2% from the house.
Insulation width from extruded polystyrene foam around the perimeter should be at least the depth of seasonal freezing of the soil.
Thickness of horizontal thermal insulation must not be less than the thickness of the vertical thermal insulation of the foundation.
Insulation of the foundation from the inside
If it is impossible to insulate the foundation from the outside, thermal insulation from the inside of the room is allowed. The thermal insulation device on the side of the room is made either by gluing extruded polystyrene foam to the wall surface using solvent-free compositions (for example, cement-based), or by fixing the insulation boards mechanically, followed by the installation of a finishing layer.
At the same time, it is obligatory to check the walls of the insulated structure for the possibility of accumulation of condensation moisture in it.
In the construction of a wall with extruded polystyrene foam, it shows that such a construction is acceptable.
How to fix polystyrene foam
for foundation waterproofing
Insulation is placed along the leveled outer surface of the walls of the insulated structure after waterproofing has been performed on it.
When insulating the foundation from the outside, mechanical fixation of XPS boards is not allowed, since in this case the continuous waterproofing coating will be broken!
Extruded polystyrene foam is attached to the waterproofed surface of the walls with glue or by melting the bituminous layer of waterproofing at 5-6 points, followed by tight pressing of the plates.
Eps bonding should begin from below laying the plates horizontally in one row. The next row of plates is installed end-to-end to the already glued bottom row. It is not allowed to re-install the glued boards, as well as change the position of the insulation after a few minutes after gluing.
Thermal insulation boards must be of uniform thickness and fit snugly to each other and to the base. At the same time, they should be placed with offset joints (staggered). If the seams between the plates are more than 5 mm, they must be filled with mounting foam. It is better to use plates with a stepped edge. They are laid close to adjacent slabs so that parts of the L - shaped edges overlap each other. This installation eliminates the appearance of cold bridges. When installing thermal insulation from two or more layers of insulation, the seams between the plates are spaced apart.
The choice of adhesive depends on the waterproofing used. When applying waterproofing of a roll or mastic type on a bitumen basis, a special or is used. When choosing an adhesive, it must be ensured that it does not contain solvents and does not dissolve the styrofoam board when applied. For gluing plates to a vertical surface and for sealing joints, it is not recommended to use ordinary mounting foam, since due to the large volumetric expansion, “heaving” of the thermal insulation layer may occur, or the plates can be detached from the surface due to the occurrence of large stresses between them.
Below ground level, the adhesive layer can be applied with several points around the perimeter and in the center, so that the moisture that collects between the surface of the plate and the building base flows down unhindered.
It is forbidden to install insulation on bituminous waterproofing that has not yet dried for the following reasons:
- during the installation process, the waterproofing elements may "disperse", after which the tightness can no longer be guaranteed;
- cold bitumen based waterproofing agents may contain solvent particles which can damage the thermal insulation material. Therefore, when applying waterproofing from cold bitumen, before installing extruded polystyrene foam boards, it is recommended to allow the surface to dry for 7 days.
basement insulation
The plinth should be insulated around the perimeter to reduce thermal bridges and protect the foundation from frost damage and cracking due to thermal expansion.
The basement of the house is divided into two parts: above and below ground level and is in humid conditions, as it is in constant contact with the ground, moistened by rain, melt water and spray drops.
The facade insulation system based on a non-water-resistant heat-insulating material, such as expanded polystyrene or mineral wool, should be located at a distance of at least 30-40 cm from the top edge of the ground so as not to be exposed to rain and melt water.
To insulate the basement, it is necessary to use materials that have zero water absorption and do not change their thermal insulation properties in a humid environment. Such material is extruded polystyrene foam.
underground part
In the recessed part of the house, the use of dowels is not required, the filled soil presses the glued insulation.
Aboveground part
In the basement area (above the ground level), extruded polystyrene foam is attached to polymer cement glue, or any other adhesive that provides good adhesion to the base.
If in the underground part of the house the fastening of the XPS is possible only with the help of adhesives, then in the above-ground part of the base it is obligatory to install facade dowels at the rate of 4 dowels per slab.
As a heat-insulating layer above ground level, it is possible to use a special brand of extruded polystyrene foam with a milled surface, which provides better adhesion of adhesive compositions. It is also possible to use standard grades of extruded polystyrene foam with a smooth surface, in this case, to improve adhesion, the surface should be milled with a brush with metal bristles or a hacksaw with fine teeth.
- Fastening of the insulation (it is carried out similarly to fastening the insulation of the entire facade system to polymer cement glue)
- Installation of the first layer of reinforcing glass mesh
The prepared adhesive solution is applied with a long stainless steel trowel onto the plate vertically in the form of a strip. The thickness of the adhesive should be about 3 mm. The solution begins to be applied from the corner of the house. After applying the adhesive solution on a segment equal to the length of the prepared mesh, it is leveled with the notched side of the grater until the same thickness of the solution is obtained over the entire surface. On a fresh adhesive solution, you need to attach the prepared piece of mesh, pressing it in several places to the glue with the edge of a grater or fingers. It is necessary to remember that the mesh edge overlaps by 10 cm. With the smooth side of the grater, it is necessary to drown the mesh in the adhesive solution - first vertically from top to bottom, then diagonally from top to bottom.
- Doweling (performed through the first layer of reinforcing glass mesh)
- Installation of the second layer of reinforcing glass mesh (similar to the first)
- Plinth finish (possible options):
- decorative plaster;
- stone slabs (attached with special glue);
- ceramic tiles (mounted on a special adhesive for decorative tiles).
Insulation of the base plate
If it is necessary to insulate the foundation slab, the heat-insulating slabs are laid on the waterproofing. If knitted reinforcement is planned to be used to reinforce a reinforced concrete monolithic foundation slab or power floor, then it is enough to protect the insulation plates from the liquid components of concrete with a polyethylene film 0.15-0.2 mm thick laid in one layer. If welding is planned for reinforcing work, then a protective screed of low-grade concrete or cement-sand mortar must be made over the film. Sheets of film are laid with an overlap of 10-15 cm on double-sided tape.
When building a building, foundation insulation is often ignored, considering this type of work to be inappropriate. Why spend a lot of time, effort and money on insulating a part of a building that is not in a residential area. Despite this, there are significant reasons for performing these works:
- 30% of heat loss occurs through the floor;
- through the foundation, the cold rises into the premises;
- thermal insulation prevents condensation;
- frost adversely affects the design of the base;
- horizontal insulation prevents soil heaving;
- the sole of the foundation is arranged below the level of soil freezing and does not perceive the effects of low temperature. The supporting structure can be destroyed due to the temperature difference at the level of the sole, and in the base wall at the ground level.
Insulation provides a stable temperature of the entire structure.
Protecting the foundation from frost influences allows you to keep the heat in the room and significantly extend the life of the building.
To date, several methods of thermal insulation are used. One of the most effective ways is to insulate the foundation with foam plastic.
Technical characteristics of penoplex
Thermal insulation "Penoplex" is made on the basis of extruded polystyrene foam. The main properties are a low coefficient of thermal conductivity, this is the main requirement for a heat-insulating material.
Benefits of Penoplex:
- low coefficient of thermal conductivity from 0.001 to 0.003 W / m * C
- practically does not absorb water. For 10 days, 0.6% moisture is collected;
- has low vapor permeability;
- durability is more than 50 years;
- resistance to aggressive environment;
- does not change parameters even under the influence of load;
- simplicity and convenience of cutting and installation of heat-insulating material;
- meets all environmental requirements;
- resistance to the influence of chemically active substances (acids, alkalis, alcohols, lime, ammonia, oils and cement-sand mortar);
- biological resistance.
Penoplex is produced as an insulating material for various building structures. The base of the building is insulated with a special type of product - Penoplex Foundation. Such material allows you to solve all the necessary tasks assigned to the thermal insulation layer. Its density protects the material from damage during seasonal expansion of soil masses.
Location and calculation of insulation
Incorrect insulation device will be ineffective. The vertical and horizontal surfaces of the foundation should be insulated to provide effective frost protection. The insulating layer must be made with minimal gaps between the piits. Should not be interrupted in separate areas where cold air currents can penetrate.
Vertical insulation is mounted on the surface of the outer wall from the upper basement cut to the very bottom of the foundation. Horizontal insulation is arranged along the perimeter of the building. It is located at the level of the sole of the foundation, or above this mark. Deepening depends on the depth of soil freezing in a particular region. Often it is arranged directly under the concrete pavement of the building. Horizontal insulation prevents the process of heaving of the soil.
The thickness of the thermal insulation layer is calculated depending on the value of the "frost index". This indicator is determined by the number of cold days in a year and their temperature. Based on the obtained layer thickness, round up to a larger multiple of the thickness of the material used.
Algorithm for calculating the volume of insulation
To determine the amount of material needed:
- Calculate the area of work (vertical and horizontal insulation);
- The result obtained is divided by 0.72, since the area of one insulation plate is 1.2 m x 0.6 m = 0.72 m2. Thus, the number of plates is determined under the condition of insulation in one layer;
- If it is necessary to arrange several layers of the same thickness, then you need to multiply the number of plates by the number of layers. If the thickness varies, then the number of plates of the second layer will correspond to the first. The thickness of foam for insulation of the foundation is from 20 to 100 mm.
The choice of adhesive for mounting foam boards
Insulation is best done together with foundation waterproofing. Products must be arranged with a special adhesive for thermal insulation systems.
Types of adhesives:
- adhesive for thermal insulation systems in the form of a dry mortar. It must be proportionally diluted with water and kneaded to the desired consistency;
- ready glue. Sold in buckets or jars, pasty consistency, ready to use;
- bituminous mastic is also suitable as an adhesive, but only on a water-soluble basis;
- you can fix the foam boards with a cement-sand mortar.
The choice of adhesive type depends on:
- location of the construction site;
- time allotted for installation;
- site conditions;
- temperature at which heating is carried out.
Insulation of the foundation with foam. Work performance technology
Subsequence:
- Excavation;
- Preparatory work;
- Waterproofing the base of the building;
- Device plates Penoplex;
- Surface plastering.
The design of the heat-insulated strip foundation consists of:
- vertical wall of the foundation;
- waterproofing;
- thermal insulation Penoplex;
- cement-sand leveling layer;
- backfilling with soil;
- horizontally laid Penoplex;
- concrete pavement.
The design of the heat-insulated slab foundation consists of:
- sand cushion;
- insulation Penoplex;
- waterproofing layer;
- screeds;
- waterproofing of end faces;
- insulation of the end faces with Penoplex;
- horizontal thermal insulation;
- concrete pavement.
Excavation
Soil is being excavated in the form of a trench to the depth of freezing in this region. To drain groundwater, a drainage pipe is arranged. At the bottom of the trench, a sand cushion is laid and crushed stone or gravel is poured. Then, a geotextile is laid at the bottom of the trench, and its edges are wrapped onto the walls of the trench. A drainage pipe is laid on the geotextile at a slope of 2 cm per meter and covered with rubble.
Preparatory work
If the insulation of an already existing building is being carried out, then the walls of the foundation could lose their integrity. Protruding sharp protrusions or fittings can damage the waterproofing or thermal insulation. The broken structure is cleaned with a brush and the surface is plastered.
The sequence of preparatory work:
- installation of lighthouse guides. They are attached to the foundation, in increments of about a meter, to the entire height of the base with a ledge above the ground of 50 cm;
- if the leveling layer is more than 2.5 cm thick, then it is necessary to reinforce this section of the foundation with a chain-link mesh;
- a cement-sand mortar is mixed in a ratio of 1: 4 of the required consistency;
- the solution is thrown onto the foundation from the bottom up;
- using the rule, the excess solution is removed. The rule is drawn from top to bottom along the guide beacons;
- The leveling layer is applied immediately after the first layer has dried.
Subsequent work is carried out only after the leveling layer has dried.
Waterproofing works
There are several ways to waterproof a foundation. The most common are:
- Bituminous waterproofing.
Bitumen is heated to a liquid consistency and applied to the foundation with a brush. It is necessary to coat with bitumen in 2 or 3 layers. The resin penetrates into all pores and prevents moisture from entering. The operating time of bitumen insulation is very short, therefore, bitumen with polymer additives is used, which prolongs the life of the material; - Roll waterproofing.
For this type of waterproofing, roofing material, technonikol, hydrostekloizol, technoelast, etc. are used. The rolled material is not able to penetrate into the pores, so it is necessary to use mastic.
The resin is applied to the surface of the foundation. After that, the roofing material is heated by a burner and glued onto the foundation structure with an overlap of 15 cm. Mastic is applied on top of the roofing material and the next layer of roofing material is arranged; - Waterproofing with liquid rubber.
This material has good adhesion to the surface, long service life and no seams. Liquid rubber is applied to the surface of the foundation. After the first layer has dried (it takes about a day), a second layer of rubber is applied.
Installation of heat-insulating plates Penoplex
Penoplex is mounted in a vertical position from the bottom up. Plates are fastened with a special glue or bituminous mastic. The use of dowels is unacceptable, because they can break the waterproofing.
Additional fastening with plastic umbrellas is possible on the plinth. It is carried out after the glue has dried. Fixation occurs at the corners and in the center of each plate.
The adhesive is applied to the slab (about 40% of the surface), which is pressed against the foundation surface and held for about a minute. Then the next plate is mounted, which is installed in the groove to the first. The gaps between the plates are covered with glue. The second layer is applied in the same way, but with an offset so that the joints of the first layer overlap.
Surface leveling
A reinforcing mesh with an overlap is mounted on Penoplex to avoid cracking. After that, plastering is carried out with a cement-sand mortar or special plasters for outdoor use.
After completing the main work, the foundation is backfilled. But not completely. At a depth of about 30 cm, sand filling is performed and the soil is rammed. Then waterproofing is laid on the sand and a horizontal heat-insulating layer of foam plastic is laid on it.
After the device of the horizontal layer, it is possible to carry out a blind area around the perimeter of the structure. With this technology of insulation, the foundation of the building will be protected from excessive heat loss. Horizontal insulation under the blind area will be the key to protecting the base of the building from the seasonal movement of soil masses.
Topics dedicated to the construction of an energy-efficient home are always popular among users of our portal. But often a well-insulated frame house is understood as energy efficient, ignoring stone houses. This is due to the fact that novice developers rely on the construction of a stone house, while the issue of energy saving requires an integrated approach. In our today's material, we will fill this gap and tell you how to properly insulate a stone structure and what should be the thickness of the wall insulation.
From this article you will learn:
- What are the basic principles of building a warm stone house.
- Why is it necessary to eliminate cold bridges in a stone house.
- What are the advantages of a single-layer stone wall.
- In what cases is it advisable to build a multi-layer insulated stone wall.
- How to calculate the optimal thickness of insulation for a stone wall.
Energy Efficiency: Basic Principles
When it comes to building a stone house, the most frequently asked questions are: will it be warm in a house made of aerated concrete with a wall thickness of 40 cm or, if a house is built from warm ceramics, will it need to be additionally insulated. Let's see if this approach is justified.
It is important to understand that the concept of a warm house is very subjective. Someone wants the house to be really hot in winter, someone, if the temperature in the room drops below + 18 ° C, will simply put on a sweater, preferring cool air in the room to "Africa". Those. each person has his own concept of a warm, and therefore comfortable home. But there is a basic definition that will help us set a benchmark for the construction of a warm stone house.
An energy-efficient dwelling is a house in which all heat losses through building envelopes and the level of energy consumption (compared to a conventional house) are minimized. To do this, a closed thermal circuit is being built and all "cold bridges" are cut off.
Cold bridges in a stone house are structures that are not thermally insulated from the external environment. This is, first of all, the foundation, lintels, ends of floor slabs, etc.
During the construction of a stone house from small-piece materials - brick, gas and foam concrete, warm ceramics, also special attention should be paid to masonry seams. Because in terms of the total wall area, the total thickness of all masonry joints becomes a powerful "cold bridge", leading to heat loss. These heat losses increase even more, if the masonry (seams) is blown. Which negates all the advantages of the so-called. "warm" wall materials - aerated concrete and large-format porous ceramic blocks. To protect the masonry from blowing, it must be plastered.
The thinner the masonry joints, the less heat escapes through the stone wall.
One way to reduce heat loss through masonry joints is.
When erecting a stone house, one should not blindly increase the thickness of the walls, believing that the masonry half a meter wide will be warm.
It is necessary to take into account:
- climatic features in the region of residence,
- duration of the heating period,
- the availability of a particular type of fuel,
- an increase in energy prices, moreover, in the long term, because it is possible to maintain a comfortable temperature even in a poorly insulated house, with large heat losses through the building envelope.
The only question is how much you have to pay for the operation of the heating system that generates heat in such a house.
Our article tells.
In addition to walls, ceilings, windows and doors, ventilation and air conditioning systems are also responsible for the “energy efficiency” in the house, through which heat is also lost. The amount of heat loss is affected by the shape and architecture of the house (the presence of ledges, bay windows, etc.), the total area of the building, the area of \u200b\u200bglazing, the location of the building on the site relative to the north and south.
Dmitry Galajuda Consultant of the "Ventilation" section on FORUMHOUSE, (nickname on the forum - Gaser)
If you insulate the walls above the norms, but make insufficient insulation of the coating, “cold windows” and install an “energy NOT efficient” natural ventilation system, then you will waste your money. The house is a system where everything must be calculated and balanced.
Conclusion: a warm stone house is a combination of many factors, each of which should be considered individually.
An example of a simplified thermal calculation
Through the walls of the house, heat escapes to the outside. Our task is to create a "barrier" that will prevent the transfer of heat from a room with a higher temperature (out of the room) to an external environment with a lower temperature (outside). Those. we must increase the thermal resistance of the building envelope. This coefficient (R) varies by region and is measured in (m²*°C)/W. What does it mean how many watts of thermal energy passes through 1 sq.m. walls with a temperature difference on the surfaces of 1°C.
Move on. Each material has its own coefficient of thermal conductivity (λ) (the ability of a material to transfer energy from a warm part to a colder ) and is measured in W/(m*°C). The lower this coefficient, the lower the heat transfer and the higher the thermal resistance of the wall.
An important condition: the coefficient of thermal conductivity increases if the material is waterlogged. A good example is a wet mineral wool insulation, which in this case loses its heat-insulating properties.
Our task is to find out whether the wall made of conditional stone material corresponds to the basic values of the required heat transfer resistance of the enclosing structures. Let's do the necessary calculations. For a simplified example Let's take Moscow and the Moscow Region. Required normalized the value of the heat resistance of the walls is 3.0 (m²*°С)/W.
Note: for floors and coatings, the normalized thermal resistance has other values.
The walls of the conditional house, 38 cm thick, were built of solid ceramic bricks. Thermal conductivity coefficient of the material λ (we take the average value dry) – 0.56 W/(m*°С). The laying was carried out on a cement-sand mortar. To simplify the calculation, heat losses through masonry joints - "cold bridges" - are not taken into account, i.e. Brick wall - conditionally homogeneous.
Now we calculate the value of the heat resistance of this wall. You don't need a calculator for this, just substitute the values into the formula:
R= d/λ, where:
d is the thickness of the material;
λ - coefficient of thermal conductivity of the material.
Rf \u003d 0.38 / 0.56 \u003d 0.68 (m² * ° C) / W (rounded value).
Based on this value, we determine the difference between the normative and actual heat transfer resistance (Rt):
Rt \u003d Rn - Rf \u003d 3.0 - 0.68 \u003d 2.32 (m² * ° С) / W
Those. the wall does not "hold out" to the required normalized value.
Now we calculate the thickness of the wall insulation, which compensates for this difference. As a heater, we take expanded polystyrene (polystyrene), intended for facade insulation with subsequent plastering, the so-called. "wet façade"
Material thermal conductivity coefficient dry- 0.039 W / (m * ° С) (we take the average value). We put it in the following formula:
d = Rt * λ, where:
d is the thickness of the insulation;
Rt - resistance to heat transfer;
λ is the thermal conductivity of the insulation.
d = Rt * λ = 2.32 * 0.039 = 0.09 m
We translate into cm and get - 9 cm.
Conclusion: in order to insulate the wall and bring the value to the normalized heat resistance, a layer of insulation is needed (in this simplified example expanded polystyrene) with a thickness of 90 mm.
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