Constructive solutions for insulation of external walls. Constructive solutions of buildings with stone walls. Coldest month

The share of wall materials in the price of a suburban real estate is 3-10%. At the same time, the effect of wall material on living comfort remains high. Even the vernacular name of the house is determined by the design of its walls.

Comfort in the house depends not only on what the walls are made of. There are a lot of factors affecting comfort. But the choice of wall material determines the basic characteristics of the house, which will forever remain with it and will not go anywhere either when replacing the heating system or repairing the roof. Even the oral definition of the house is based on the choice of wall material: stone, wooden, frame. The wall structure seems to be a fundamental characteristic of the structure even at the household level.

This article will not say a word about the advantages and disadvantages of various materials in terms of environmental friendliness, durability or the effect on the indoor climate. These issues deserve separate consideration. Our article focuses on another aspect of choice: the likelihood of hidden defects. It will be about how realistic it is to achieve the characteristics that are declared by manufacturers and are used in the calculations by designers, heat engineers and other specialists.

In general, a wall is:

1. Constructive solution of the wall (load-bearing, heat-insulating, steam-and-windproof, finishing, etc. layers);
2. A constructive solution of its individual nodes (installation of windows and doors, adjoining ceilings, roofs, partitions, laying communications and other heterogeneities);
3. Actual implementation of design decisions.

Project feasibility

There are no formal criteria for reliability and feasibility. We cannot evaluate the resistance to marriage based on standards. Therefore, we determine the feasibility of design decisions based on common sense considerations.

Resistance to marriage consists of two components:

1. The fundamental opportunity to allow accidental marriage in good faith work;
2. The ability to check the quality of the finished wall without disassembling, without the use of sophisticated equipment and at any time of the year.

Both of these components are equally important when choosing a constructive solution to the wall. And depending on whether construction is underway with your own hands or with the involvement of contractors, the emphasis when choosing a wall construct may shift from the probability of an accidental marriage to the possibility of a visual assessment of the quality of already completed work.

Brief classification of exterior walls

1. The supporting frame with filling. Example: power frame - boards or metal profile, sheathing and filling (from inside to outside) - GVL (GKL, OSB), plastic film, insulation, wind protection, lining.

2. Support wall with external insulation with separation of the carrier and heat-insulating functions between the layers. Example: a wall made of bricks, stones or blocks with an external insulation (expanded polystyrene or mineral wool board) and cladding (front brick, plaster, curtain wall with an air gap).

3. Single layer wall from a material that performs both the supporting and the insulating functions. Example: an unfinished log wall or a plastered brick wall.

4. Exotic systems with fixed formwork we will remove from consideration due to low prevalence.

Let's try to understand at what stages of construction work deviation from design decisions and the occurrence of marriage are possible.

Frame constructions

At the mention of frame buildings there is no need to give the palm in their invention to Canada. Shield houses appeared with us long before the fall of the Iron Curtain. Therefore, it is quite feasible for us to evaluate their reliability. Construct: vertical and horizontal power elements of the frame, braces or sheet sheathing, giving the structure rigidity.

There are no questions to the realizability of the framework itself - the assembled framework allows the simplest means to evaluate its quality. Visual evenness and verifiable stiffness when horizontal loads are applied are sufficient to take the frame into operation. Another thing is layers designed to provide thermal protection.

Insulation. Must densely fill all cavities formed by power elements. A task that is difficult to achieve with a step between the elements of the frame, which differs from the dimensions of the plate insulation. And it is almost not feasible in the presence of diagonal braces in the structure of the frame (of course, there are pouring and filling insulation, devoid of these shortcomings - here we are talking about the most common filling options).

Vapor barrier. Highly vapor permeable film layer. It must be installed with sealing joints, without weakening by perforation from mechanical fastening elements, with especially careful execution around window and door openings, as well as at the places where communications come out of the wall, hidden in the thickness of the insulation of electrical and other wiring, etc. In theory, vapor barrier can be done soundly and thoroughly. But in case you are a customer receiving a finished construction, the quality of the vapor barrier of the wall already sheathed from the inside is not checked.

Walls with external insulation

A constructive solution that has spread over the past twenty years, while tightening regulatory requirements for thermal protection and rising energy prices. The most common are two options:

• bearing stone wall (200-300 mm) + insulation + cladding in 1⁄2 brick (120 mm);
• supporting stone wall (200–300 mm) + insulation glued and fixed with dowels + reinforced plaster for insulation or air gap, wind protection and sheet cladding.

There are practically no questions to the bearing layer of the wall. If the wall is folded fairly evenly (without obvious deviations from the vertical), its bearing capacity will almost always be sufficient to perform its main - bearing - function. (In low-rise construction, the strength characteristics of wall materials are rarely used when fully used.)

Insulation. Glued to a load-bearing wall, mechanically fixed to it, sheltered by a layer of reinforced plaster, it does not cause problems. You can make a mistake in choosing glue, dowels, plaster composition - then after some time the layer of thermal insulation or finish begins to lag behind the wall. In general, the quality is checked by means of visual control, and the pop-up marriage is obvious.

The quality of work with a suspended facade with an air gap is not so obvious. To check the density of the insulation installation, dismantling of the cladding is necessary, installation of wind protection also requires intermediate acceptance.

When facing a brick with insulation, the quality of its installation cannot be checked even with a thermal imager. And marriage can be eliminated only after dismantling the cladding (read - demolition of a brick wall).

Single layer walls

A wall made of logs or beams, folded using a high-quality intervening seal and not lined with anything, is checked for compliance with the project by a simple inspection. Cracking of wood, reducing the reduced thickness of the log by 40-60%, and shrinkage of 6-8%, we will not consider here.

Hollow stones. These include hollow concrete blocks and multi-hollow large-format ceramics. Hollow blocks made of heavy concrete will not provide the required thermal resistance, and therefore can only act as part of the wall from the previous section. A single-layer wall made of large-format ceramic, plastered on both sides, is guaranteed to be protected from blowing. Its thin spots: angles other than 90 ̊ and masonry seams.

Processing brittle multi-slit blocks to create a non-right angle leads to the formation of an openwork abutting surface and a thick vertical mortar seam. But the horizontal masonry seams have a much greater influence on the deviation of the wall from the calculated characteristics. First, they themselves are already bridges of cold. Secondly, according to the rules, in order to avoid filling the voids with a solution, it is necessary to roll a fiberglass mesh with a cell of 5x5 mm on top of the stone before laying the solution. In this case, the mobility of the solution should be carefully monitored to prevent it from flowing through the mesh cells.

Thus, the occurrence of random marriage is possible even with conscientious work. When performing work by a contractor, there is no opportunity to evaluate the quality of masonry without using a thermal imager.

Corpulent stones. These include wall blocks made of cellular or lightweight concrete and solid brick. The quality of a solid brick wall can be evaluated from afar with the naked eye, so there is no reason to talk about hidden marriage in relation to such masonry. The disadvantage of solid brick, as well as concrete stones with high density, is the relatively high thermal conductivity. Such walls require additional thermal insulation, which returns us to the previous section, to walls with external insulation.

Cellular concrete blocks remain. At a density of more than 500 kg / m3, as well as when using a conventional cement-sand mortar with a joint thickness of more than 10 mm, it makes sense to additionally warm the wall, which deprives its design of elegant simplicity. And only cellular concrete with a density of up to 500 kg / m3, with high geometric accuracy of the blocks, which allows laying on thin-layer mortar, gives us a structure so simple that the appearance of hidden defects in it is simply impossible.

A single-layer wall made of aerated concrete of low density with adhesive joints 1-3 mm thick.

Spoiling it is not easy. For example, the blocks can be folded dry, without any bonding to each other, just like children's blocks. If then you plaster such a wall on both sides on a grid - it will fulfill all the tasks assigned to it by 100%. The thermal protection of a dry-folded structure (and stuccoed on both sides) of the structure will not decrease, but will even increase somewhat due to the absence of heat-conducting mortar layers. At the same time, the ability to absorb vertical loads, the general rigidity and stability of such a wall in the presence of a strapping belt at the level of overlap will not differ from the calculated ones.

The accuracy of the geometrical dimensions, the large format of the blocks and the thin-layer glue make it impossible in principle to stack the masonry with noticeable deviations from the vertical or any irregularities. The masonry automatically turns smooth even by an inexperienced mason. Angles other than 90 ̊ are made using a conventional hand saw. Preparation for finishing is done by simple puttying of seams, i.e. as easy as before plasterboard finishing.

There is no equal to the protection against hidden defects in a single-layer wall. In terms of protection against defects in general, both hidden and explicit, there is no equal to a single-layer wall of cellular concrete blocks with a density of up to 500 kg / m3. Only such a wall made in the material will be guaranteed to comply with the design decision.

It is known that single-layer building envelopes made of currently known building materials cannot provide the thermal protection of a building that is required by modern energy-saving standards, therefore, it is necessary to initially provide a multi-layer fence that has an effective insulation, and in some cases air-ventilated interlayer.

When developing a constructive solution for walls and coatings, we proceeded from the requirements for the design resistances of building envelopes at the third level of thermal protection [KMK].

In accordance with this regulatory document, it is prescribed to take the calculated heat transfer resistance depending on the degree-day of the heating period (GSOP), determined by the formula (2.6).

For the city of Tashkent, the parameters necessary for the calculation, determined by KMK 2.01.01-94, were:

• - the temperature of the coldest day with a security of 0.92 and five days with a security of 0.98 is tn \u003d - 160C;
• - average temperature of the heating period tot.per \u003d + 2.70 ° C;
• - the duration of the heating period Zot.per \u003d 129 days.

The air temperature inside the premises to ensure a sufficient level of comfort was taken equal to tv \u003d + 200C.

Then the GSOP \u003d (20 - 2.7) x129 \u003d 2232 degrees x days.

With such a value of the GSOP on change 1 to KMK 2.01.04-07 we accept:

• - for the walls of buildings, the calculated heat transfer resistance under winter operating conditions Rtr0 \u003d 2, 1 m2 · 0С / W;
• - for coatings Rtr0 \u003d 2.8 m2 · 0С / W.

Thermotechnical calculations were performed using the BASE software package (version 7.3).

The external walls for the calculation were taken of the following constructive solution (Fig. 3.12):

• - M50 cement-sand mortar, 20 mm thick;
• - ordinary clay brick M75 on cement-sand mortar brand M-50 with a thickness of 380 mm;
• - insulation made of polystyrene foam;
• - cement-sand mortar M50, 20 mm thick.

Fig. 3.12.

As a result of the calculation, the insulation thickness of 80 mm was adopted. Then, the adopted design was tested for heat resistance under summer operating conditions.

Calculation results

1. - Source data:

Type of building - Administrative.

Type of construction - WALL

Table 3.1

Feature fencing:

It is required to produce:

maximum 744 W / m2

average 275 W / m2

Exterior Finish: Cream cement plaster

The absorption coefficient of solar radiation 0.4

2. - Conclusions:

The required resistance of the heat transfer barrier is 2.1 m2 * deg / W

Actual (reduced) heat transfer resistance of the enclosure is 2.21 m2 * deg / W

Table 3.2

Actual air permeation resistance 656.45 m2 * h * Pa / kg

The amplitude of the temperature fluctuation of the inner surface of 0.04 degrees C.

Filling of window openings and glazing of greenhouses was taken without calculation, based on the range of products for this purpose available in Uzbekistan - single-chamber double-glazed windows in plastic bindings of ordinary glass with reduced heat transfer resistance equal to 0.36 m2 · 0С / W.

The constructive solution of the attic floor covering for calculation was the following (Fig. 3.13):

• - drywall with a thickness of 10 mm;
• - solid wood flooring 20 mm thick;
• - insulation from extruded polystyrene foam 40000С;
• - vapor barrier layer of roofing glaze 0.4 mm thick;
• - airspace 40 mm thick;
• - metal tile.

Fig. 3.13.

Insert heat transfer calculation printout

As a result of the calculation, the insulation thickness of 140 mm was adopted. Then, the adopted design was tested for heat resistance under summer operating conditions.

Calculation results

Thermotechnical calculation of enclosing structures

1. - Source data:

Type of building - Public, administrative, household

Type of construction - COATING

Fencing operating conditions:

Outside temperature -16 degrees.

The temperature of the internal air is 20 degrees.

The average temperature of the heating period is -2.7 degrees.

The duration of the heating period is 129 days

Table 3.3

Feature fencing:

Layer number	Thickness m	Name	Value	Units measuring	Layer material
		Thermal conductivity		W / (m * deg)	Drywall
		Thermal conductivity		W / (m * deg)	Pergamine
		Thermal conductivity		W / (m * deg)	Expanded polystyrene G \u003d 100kg / m3
		Thermal conductivity		W / (m * deg)	Pergamine
		Thermal conductivity		W / (m * deg)

The heat transfer coefficient of the inner surface of 8.7 W / (m2 * deg)

Heat transfer coefficient of the outer surface 23 W / (m2 * deg)

The operating mode of the building envelope:

Exploitation; room mode - Normal (55%); humidity zone - Normal

It is required to produce:

Checking the fencing for heat transfer resistance

Calculation of the building envelope for heat resistance

The calculation of the enclosing structure for breathability

The average monthly temperature in July is 27.1 degrees.

The amplitude of daily air fluctuations in July is 23.7 degrees.

The minimum wind speed in July is 1.4 m / s

The value of total solar radiation, for walls - as for vertical surfaces, for coatings - as for horizontal:

maximum 1022 W / m2

average 497 W / m2

Exterior Finish: Galvanized Steel Roofing

The absorption coefficient of solar radiation 0.65

Building height to the top of the exhaust shaft 11.7 m

The maximum wind speed in January 2.1 m / s

2. - Conclusions:

Enclosure resistance to heat transfer is SUFFICIENT

The required resistance of the fence to the heat transfer of 2.8 m2 * deg / W

Actual (reduced) heat transfer resistance of the enclosure 2.95 m2 * deg / W

Table 3.4

The temperature at the contact of the layers of the fence:

Actual air permeation resistance 130 100 160 m2 * h * Pa / kg

Normalized resistance to air permeation of 24.87 m2 * h * Pa / kg

Resistance to vapor permeability is SUFFICIENT.

The amplitude of the temperature fluctuations of the inner surface of 0.96 degrees C.

The normalized amplitude of surface temperature fluctuations is 1.89 degrees.

The heat resistance of the building envelope is SUFFICIENT.

Insert printout of calculation for heat resistance

No less importance is given in the practice of designing and insulating floors on the first floor of a building, since large heat losses pass through floors constructed without thermal insulation. In addition to reducing heat loss, floor insulation allows more efficient use of their heat capacity. The temperature of the floor surface is the main factor determining the degree of comfort of the premises. In our case, to insulate the floor of all rooms on the first floor, with the exception of the hall, a constructive decision was made, presented in Fig. 3.14.

Fig. 3.14.

A calculation was made to determine the thermal resistance of the insulated floor and the insulated floor of the hall.

Insert calculations

Thus, the calculated resistance of the insulated floor was Ro ut.p. \u003d 0.57 m2 · 0С / W; and the "cold" floor of the hall Ro hall .. p. \u003d 0.39 m2 · 0С / W;

In the end, the designed building envelope was checked for increased thermal protection according to formula (2.8).

In the designed building, the areas of enclosing structures were determined, which amounted to:

• - wall area - 652 m2;
• - roof area - 357 m2;
• - the area of \u200b\u200bthe insulated floor - 139 m2;
• - cold floor area - 104 m2;
• - glazing area - 166 m2;

Then the calculated resistance of the outer shell of the building will be: Rob \u003d (Rst Sst + RokSok + 0.8 RkrSkr + 0.5RosnSosn + 0.5Rab Sab) / Sob \u003d 2.21 * 485 + + 0.36 * 166 + 0.8 * 357 * 2.95 + 0.5 (0.57 * 139 + 104 * 0.39) \u003d 1.62 m2. 0С / W.

Since the obtained value is 45% higher than the required value, it is possible to reduce the thickness of the heat-insulating layer on the wall panels and the attic floor, and there is no need to warm the floors of the 1st floor.

We reduce the thickness of the insulation on the walls from 80 mm to 60 mm, while Rst \u003d 1.82 m2. 0С / W; we reduce the thickness of the insulation in the coating from 140 mm to 100 mm, while Rcr \u003d 2.15 m2. 0С / W. The calculated resistance of the entire floor surface of the 1st floor is taken Roc \u003d 0.39 m2. 0С / W. For this thermal protection solution:

Rob \u003d (Rst Sst + RokSok + 0.8 RcrScr + 0.5RosnSosn + 0.5Rab Sab) / Sob \u003d 1.82 * 485 + + 0.36 * 166 + 0.8 * 357 * 2.15 + 0, 5 (243 * 0.39) \u003d 1.23 m2. 0С / W.

Rob \u003d 1.23\u003e 1.21 m2. The 0С / W received solutions is the most economical, meets the European requirement for increased thermal protection of buildings.

Modern building standards require additional insulation of stone walls, because otherwise their thickness would be too large. But, if there are no technical issues when laying a thick wall, the multilayer structure, which includes insulation, poses these questions, and quite acutely. Errors made during insulation can be very expensive, and to avoid them, it is necessary to thoroughly study the theoretical part.

Frankly, the issue of insulation is one of the most difficult in construction. The main problem that has long haunted heat technicians is the moisture of the insulation. As you know, the more the heater is moistened, the worse it copes with its function.

The technology of warming the building envelopes depends on the materials from which they are built. In this article we will consider the main options for warming stone walls, i.e. made of various building stones, in particular, ceramic and silicate bricks, cellular concrete blocks, porous ceramics; and also from cast concrete.

There are three main ways to insulate stone walls:

• outside of the enclosing structure;
• in the thickness of the enclosing structure;
• from the inside of the building.

Of these, internal insulation is considered the worst option, since the masonry in this case is not protected from external factors. In addition, with internal insulation, high-performance ventilation of the premises is necessary, otherwise condensation will form on the walls. The savings in internal insulation are only apparent, but in reality they are not at all, given operational factors.

In cottage construction, external and layered (in the thickness of the wall) insulation is most often used. But they also have a number of drawbacks, which are necessary, if not eliminated, then minimized. Multilayer walls, in which the insulation is located between the supporting structure and the outer brick layer, is a very common solution. Such walls give the house a solid look and, as expected, do not need periodic updating of the facade.

As insulation use mineral wool or regular polystyrene foam, less often - extruded, due to its high cost. In puff walls, mineral wool, subject to a number of technological requirements for laying it, works better than other heaters. Its main advantage is the vapor permeability, which expanded polystyrene, especially extruded, is devoid of. However, this advantage can work against the wool itself and the wall structure as a whole, if you do not take into account the fact that the insulation is too wet.

It is very important to understand that the best option for warming residential buildings is one in which each subsequent layer is more vapor permeable than the previous one in the direction of diffusion of water vapor - from the inside out. If the mineral wool is clamped with two layers of brickwork, then it will quickly moisturize and lose the properties of the insulation. Water vapor traveling from inside the building to the outside, passing through the insulation, will abut the cold masonry and become absorbed by cotton. To combat this phenomenon is possible and necessary. For this, a 2 cm ventilated gap is left between the cotton and the outer layer, and ventilation holes in the form of unfilled vertical joints are made in the lower and upper rows of the masonry. Such a scheme is not a full-fledged ventilated facade, but significantly reduces the degree of moisture of the fibrous insulation. Condensate falls out on the inner surface of the outer layer, but does not come in contact with the cotton wool, but flows down and is partially discharged through the ventilation holes.

For the correct implementation of layered masonry with mineral wool insulation, it is necessary to use embedded parts that will connect both layers of the wall. It can be special flexible connections from steel with a corrosion-resistant coating, fiberglass or basalt plastic. They are installed in increments of 60 cm horizontally and 50 cm vertically. Communications also perform the function of fastener insulation.

Expanded polystyrene is four times cheaper than mineral wool and is not inferior to it in terms of resistance to heat transfer. It is the cheapness of expanded polystyrene that makes it the most common heater in puff walls. However, the problem associated with its low vapor permeability does not allow calling this material ideal for use in layered masonry. Obviously, the issue of vapor diffusion is not the easiest for non-specialists to understand, and therefore many customers choose expanded polystyrene, especially since the builders do not strongly dissuade them from this. The consequences of low vapor permeability of the insulation do not appear immediately, but when the problems become obvious, it will be quite difficult to make a complaint. And the consequences are as follows: the bearing layer of the wall can be waterlogged; in a room where there is no enhanced ventilation, a characteristic odor of mold may appear, interior decoration, etc., may be disturbed.

Expanded polystyrene is a combustible material, and therefore it cannot be left open and, of course, no vented gaps can be used. In addition, according to the requirements of SP 23-101-2004 “Design of thermal protection of buildings”, when using foams for insulation, window and other openings must be framed around the perimeter with mineral wool strips.

As we can see, polystyrene foam and mineral wool have flaws in the structure of puff walls. Cotton wool gets wet, and expanded polystyrene does not let steam through. If you insulate the mineral wool insulation from the inside, then the vapors will not penetrate into its thickness, but forced ventilation will be necessary to remove them. The problem of moistening the cotton wool is removed if you leave a ventilation gap between it and the facade layer. In the case of expanded polystyrene, only intensive ventilation can help.

It should be noted that the efficiency of the heat insulators in the layered masonry and the durability of the layered enclosing structure as a whole largely depends on the quality of installation. If mistakes were made, then they can no longer be corrected.

Exterior insulation with plaster

This method of insulation is better known as "wet facade" or "facade insulation". External insulation is less expensive than layered; Moreover, an indirect cost reduction arises due to the less powerful foundation, which is not loaded with a stone facade layer. The bearing part of the wall is completely protected from all external factors that could shorten its service life. In addition, external insulation does not allow water vapor to condense in the thickness of the wall, so that it does not damp. True, this happens only with the high-quality performance of all technological layers; with their correct calculation and location.

In external insulation systems both mineral wool and facade polystyrene foam (grade 25F) are used. The plaster layers that form the external finish can be thin-layer (7–9 mm) and thick-layer (30–40 mm). Fine stucco on a warm facade is the most common. Regardless of the type of insulation, its plates are mounted to the wall with glue and plate dowels (5 pcs / m²), the main bearing function being the glue and the dowels help to cope with the wind load.

The standard facade insulation system, starting from the wall, consists of:

• penetrating primer;
• adhesive layer;
• thermal insulation (calculated based on the lack of resistance to heat transfer);
• alkali-resistant fiberglass mesh enclosed in a layer of adhesive solution;
• quartz primer;
• plaster layer.

At the ground floor level, the plaster layer is made twice as thick to withstand possible shock loads.

Warming of the cottage from the outside is usually carried out by a hired team, since it is quite difficult to cope with a large amount of work on your own, and most importantly for a long time. And when mineral wool boards are used as insulation, it is necessary to finish them as soon as possible so that the rain does not wet them. Expanded polystyrene is also not recommended to be left without finishing for a long time, as it is rapidly destroyed by solar ultraviolet radiation.

It is best to use proprietary facade insulation systems, as this eliminates material selection errors. With self-selection, there is a risk that some technological layers will begin to conflict with each other, which will entail their detachment up to the collapse of the facade.

Warm facades with the use of combustible heaters, in particular expanded polystyrene, need fire cuts - dividing 15 cm strips of stone wool into floors and framing the same strips of window openings, as well as arranging balconies and loggias over the entire area.

The durability of external facade insulation systems is estimated for decades, but only if the technology is carefully observed. So, when using mineral wool for insulation, it is important to use vapor-permeable plaster, otherwise the fibrous insulation will accumulate moisture diffusing from the rooms and abut against a pan-tight layer of acrylic plaster.

[ outdoor house walls, technology, classification, mason, design and laying of load-bearing walls]

Fast passage:

• Shrink and sedimentary joints
• Exterior Wall Classification
• Single and multi-layer wall structures
• Panel concrete walls and their elements
• Design of panels of load-bearing and self-supporting single-layer walls
• Three-layer concrete panels
• Methods for solving the main problems of designing walls in concrete panel structures
• Vertical joints and Connections of external wall panels with internal
• Heat and insulation ability of joints, types of joints
• Compositional and decorative features of panel walls

The designs of the exterior walls are extremely diverse; they are determined by the building's building system, wall material and their static function.

General requirements and classification of structures

Fig. 2: Expansion joints

Fig. 3: Details of the structure of temperature seams in brick and panel buildings

Shrink joints suit in order to avoid the formation of cracks and distortions caused by the concentration of forces from exposure to variable temperatures and shrinkage of the material (masonry, monolithic or prefabricated concrete structures, etc.). Shrink joints cut through the structure of only the ground part of the building. Distances between heat-shrinkable joints are assigned in accordance with climatic conditions and physicomechanical properties of wall materials. For clay brick exterior walls with M50 brand mortar and more, distances between heat-shrinkable joints of 40-100 m are taken according to SNiP “Stone and stone-stone structures”, for exterior walls of concrete panels 75-150 m according to BCN32-77, Gosgrazhdanstroy “Instruction on the design of structures of panel residential buildings. " At the same time, the smallest distances belong to the most severe climatic conditions.

In buildings with longitudinal load-bearing walls, seams are arranged in the area adjacent to the transverse walls or partitions, in buildings with transverse load-bearing walls, seams are often arranged in the form of two paired walls. The smallest joint width is 20 mm. Seams must be protected from blowing, freezing and through leaks with the help of metal expansion joints, sealing, insulating liners. Examples of structural solutions for heat-shrink joints in brick and panel walls are given in Fig. 3.

Sedimentary seams it should be provided in places of sharp changes in the number of storeys of the building (sedimentary seams of the first type), as well as with significant unevenness of deformations of the base along the length of the building caused by the specifics of the geological structure of the base (sedimentary seams of the second type). Sedimentary joints of the first type are used to compensate for differences in the vertical deformations of the ground structures of the high and low parts of the building, in connection with which they are arranged similarly to temperature-shrinkage only in ground structures. The design of the seam in frameless buildings provides for a sliding seam in the area of \u200b\u200bsupporting the overlap of the low-rise part of the building on the walls of the multi-storey building, in frame structures - hinged support of the crossbars of the low-rise part on the multi-storey columns. Sedimentary seams of the second type cut the building to the entire height - from the ridge to the base of the foundation. Such joints in frameless buildings are designed in the form of paired transverse walls, in frame - paired frames. The nominal width of the sedimentary joints of the first and second types is 20 mm. The design features of an earthquake-resistant building, as well as buildings constructed on subsidence, undermining and permafrost soils, are considered in a separate section.

Figure 4: Exterior Wall Views

Exterior Wall Structures classified by signs:

• the static function of the wall, determined by its role in the structural system of the building;
• material and construction technology, shared by the building's building system;
• constructive solutions - in the form of a single-layer or layered enclosing structure.

According to the static function, the bearing, self-supporting or non-bearing wall structures are distinguished (Fig. 4).

Bearing walls, in addition to perceiving the vertical load from their own mass, transmit to the foundations loads from adjacent structures: ceilings, partitions, roofs, etc.

Self-supporting the walls perceive the vertical load only from their own mass (including the load from balconies, bay windows, parapets and other wall elements) and transfer it to the foundations directly or through basement panels, randbalks, grillage or other structures.

Table 1 Detection Wall Designs

1 - brick; 2 - small block; 3, 4 - insulation and air gap; 5 - lightweight concrete; 6 - autoclaved cellular concrete; 7 - structural heavy or lightweight concrete; 8 - log; 9 - caulking; 10 - timber; 11 - a wooden frame; 12 - vapor barrier; 13 - airtight layer; 14 - a covering from boards, waterproof plywood, chipboard or others; 15 - lining of inorganic sheet materials; 16 - metal or asbestos-cement frame; 17 - ventilated air gap

Exterior walls may be single layer or layered designs. Single layer walls erected from panels, concrete or stone blocks, monolithic concrete, stone, brick, wooden logs or beams. In laminated walls, various functions are assigned to various materials. Strength functions are provided by concrete, stone, wood; longevity functions - concrete, stone, wood or sheet material (aluminum alloys, enameled steel, asbestos cement, etc.); insulation functions - effective heaters (mineral wool boards, fiberboard, expanded polystyrene, etc.); vapor barrier functions - rolled materials (cushioning ruberoid, foil, etc.), dense concrete or mastics; Decorative functions - various facing materials. Among the layers of such an enclosing structure, an air gap may be included. Closed - to increase its resistance to heat transfer, ventilated - to protect the room from radiation overheating or to reduce deformations of the outer facing wall.

Single and multi-layer wall structures can be made prefabricated or in traditional technology.

The main types of structures of external walls and their application are shown in Table. 1.

The purpose of the static function of the outer wall, the choice of materials and structures is carried out taking into account the requirements of SNiP "Fire safety standards for the design of buildings and structures." According to these standards, load-bearing walls, as a rule, should be fireproof. The use of hard-burning load-bearing walls (for example, wooden plastered) with a fire resistance of at least 0.5 hours is allowed only in one-two-story houses. The fire resistance of non-combustible wall structures should be at least 2 hours, and therefore they must be made of stone or concrete materials. High requirements for fire resistance of load-bearing walls, as well as columns and pillars, are due to their role in the safety of a building or structure. Damage during a fire to vertical load-bearing structures can lead to the collapse of all structures and the building as a whole.

Non-load-bearing exterior walls are designed to be fireproof or hardly combustible with significantly lower fire resistance limits (0.25-0.5 hours), since the destruction of these structures from the effects of fire leads only to local damage to the building.

Non-combustible non-bearing external walls should be used in residential buildings above 9 floors, with a lower number of floors, the use of hardly combustible structures is allowed.

The thickness of the outer walls is selected according to the largest of the values \u200b\u200bobtained as a result of static and thermotechnical calculations, and is assigned in accordance with the structural and thermotechnical features of the enclosing structure.

In prefabricated concrete housing construction, the calculated thickness of the outer wall is linked to the nearest larger value from the unified series of thicknesses of the outer walls adopted for the centralized manufacture of molding equipment of 250, 300, 350, 400 mm for panel and 300, 400, 500 mm for large-block buildings.

The estimated thickness of the stone walls is consistent with the dimensions of the brick or stone and taken equal to the nearest larger structural thickness obtained during masonry. With a brick size of 250X120X65 or 250X X 120x88 mm (modular brick), the thickness of the walls of continuous masonry is 1; 1 1/2; 2; 2 1/2 and 3 bricks (taking into account vertical joints of 10 mm between individual stones) is 250, 380, 510, 640 and 770 mm.

The structural thickness of the wall made of sawn stone or lightweight concrete small blocks, the unified dimensions of which are 390X190X188 mm, when laying in one stone is 390 and in 1/2 g - 490 mm.

In some cases, the thickness of walls made of non-concrete materials with effective heat insulation materials is greater than that obtained by the thermotechnical calculation due to design requirements: increasing the wall cross-section may be necessary for reliable insulation of joints and joints with filling openings.

The construction of the walls is based on the comprehensive use of the properties of the materials used and solves the problem of creating the necessary level of strength, stability, durability, insulation and architectural and decorative qualities.

4

4.1. abouttweet: Yes (file address Block 3)

Your answer is correct, because walls are bearing only when they perceive the load from their own weight and from other structural elements of the building.

Go to question 4.2.

.1.answer: yes

4

4.1. abouttweet: NO (file address Block 3)

Your answer is incorrect, because YOU did not take into account that walls that do not accept the load from other elements of the building belong to the categories of either self-supporting or non-bearing.

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.1.answer: NO

Wall construction solutions

The thickness of the outer walls is selected according to the largest of the values \u200b\u200bobtained as a result of static and thermotechnical calculations, and is assigned in accordance with the structural and thermotechnical features of the enclosing structure.

In prefabricated concrete housing construction, the calculated thickness of the outer wall is linked to the nearest larger value from the unified series of thicknesses of the outer walls adopted for the centralized manufacture of molding equipment of 250, 300, 350, 400 mm for panel and 300, 400, 500 mm for large-block buildings.

The estimated thickness of the stone walls is consistent with the dimensions of the brick or stone and taken equal to the nearest larger structural thickness obtained during masonry. With a brick size of 250 × 120 × 65 or 250 × 120 × 88 mm (modular brick), the thickness of the walls of continuous masonry is 1; 1.5; 2; 2.5 and 3 bricks (including vertical joints of 10 mm between the individual stones) are 250, 380, 510, 640, and 770 mm.

The structural thickness of the wall of sawn stone or lightweight concrete small blocks, the unified dimensions of which are 390 × 190 × 188 mm, when laying in one stone is 390 and 1.5 - 490 mm.

Wall construction is based on the comprehensive use of the properties of the materials used and solves the problem of creating the necessary level of strength, stability, durability, insulation and architectural and decorative qualities.

In accordance with modern requirements for the economical use of materials, they try to use the maximum amount of local building materials when designing low-rise residential buildings with stone walls. For example, in areas remote from highways, small stones of local production or monolithic concrete in combination with local insulation and local aggregates, for which only imported cement is required, are used for walling. In the villages located near the industrial centers, they design houses with walls from large blocks or panels manufactured at the enterprises of this region. Currently, stone materials are gaining widespread use in the construction of houses in garden plots.

When designing low-rise houses, two schemes of constructive solutions of external walls are usually used - solid walls of homogeneous material and lightweight multilayer walls of materials of different densities. For the construction of internal walls use only solid masonry. When designing external walls according to the continuous masonry scheme, less dense materials are preferred. This technique allows you to achieve the minimum wall thickness in terms of thermal conductivity and more fully use the carrying capacity of the material. It is advantageous to use high-density building materials in combination with low-density materials (lightweight walls). The principle of lightweight walls is based on the fact that the layer (s) of high-density materials (γ\u003e 1600 kg / m 3) perform the supporting functions, and the low-density material serves as a heat insulator. For example, instead of a solid outer wall of clay brick with a thickness of 64 cm, you can use a lightweight wall structure of a layer of the same brick with a thickness of 24 cm, with a 10 cm thick fiberglass insulation. Such a replacement leads to a decrease in wall weight by 2.3 times.

For the manufacture of walls of low-rise buildings, artificial and natural small stones are used. Currently, artificial calcining stones are used in construction (clay brick is solid, hollow, porous and ceramic blocks); non-fired stones (silicate brick, hollow blocks made of heavy concrete and solid blocks made of light concrete); natural small stones - ragged boot, sawn stones (tuff, pumice, limestone, sandstone, shell rock, etc.).

The size and weight of the stones are designed in accordance with the technology of manual masonry and taking into account the maximum mechanization of work. The walls are laid out of stones with filling the gap between them with a solution. More often use cement-sand mortars. For laying internal walls using ordinary sand, and for external walls, low-density sand (perlite, etc.). Masonry walls are subject to compliance suture dressings (4.6) in series.

As already noted, the width of the wall masonry is always a multiple of the number of halves of the brick. The rows facing the front surface of the masonry are called front verst, and facing the inside - inner verst. The rows of masonry between the inner and front verst are called clouding. Bricks laid long side along the wall form spoon rowand the walls laid across tychkovy row. Masonry system (4.7) is formed by a specific arrangement of stones in the wall.

The row of masonry is determined by the number of spoon and bonder rows. With a uniform alternation of spoon and poke rows, a two-row (chain) masonry system is obtained (Fig. 4.5b). A less labor-consuming multi-row masonry system, in which a single row of bricks binds five spoon rows (Fig. 4.5a). In the walls of small blocks erected according to a multi-row system, a single row of rows connects two spoonful rows of masonry (Fig. 4.5c).

Fig.4.5. Types of masonry walls: a) - multi-row brickwork; b) - chain brickwork; c) - multirow masonry; d) - chain masonry

Solid masonry of high-density stones is used only for the construction of internal walls and pillars and external walls of unheated rooms (Fig. 4.6a-g). In some cases, this masonry is used for the construction of external walls according to a multi-row system (Fig. 4.6a-c, e). A two-row stone masonry system is used only when necessary. For example, in ceramic stones, cracks of voids are recommended to be placed across the heat flux in order to reduce the thermal conductivity of the wall. This is achieved with a chain masonry system.

Lightweight external walls are designed in two types - with a heater between two walls of a continuous masonry or with an air gap (Fig. 4.6i-m) and with a lining of a heater with a wall of a continuous masonry (Fig. 4.6n, o). In the first case, there are three main structural options for walls - walls with horizontal outlets of anchor stones, walls with vertical diaphragms made of stones (well masonry) and walls with horizontal diaphragms. The first option is used only in cases where light concrete is used as insulation, which monolizes anchor stones. The second option is acceptable for insulation in the form of pouring light concrete and laying thermal liners (Fig.4.6k). The third option is used for insulation from bulk materials (Fig.4.6l) or from lightweight concrete stones. Continuous masonry of walls with an air gap (Fig. 4.6m) also belongs to the category of lightweight walls, since a closed air gap serves as a layer of insulation. The thickness of the interlayers should be taken equal to 2 cm. An increase in the interlayer practically does not increase its thermal resistance, and a decrease sharply reduces the effectiveness of such thermal insulation. More often, the air gap is used in combination with insulation plates (Fig.4.6k, o).

Fig. 4, 6, Options for manual masonry of the walls of low-rise residential buildings: a), b) - solid external walls of brick; c) - continuous internal brick wall; d), g) - continuous external walls of stones; d), e) - continuous internal walls of stones; i) -m) - lightweight walls with internal insulation; m), o) - lightweight walls with external insulation; 1 - brick; 2 - plaster or cladding with sheets; 3 - artificial stone; 4 - plate insulation; 5 - air gap; 6 - vapor barrier; 7 - wooden antiseptic rail; 8 - filling; 9 - solution diaphragm; 10 - lightweight concrete; 11 - natural frost-resistant stone

To insulate stone walls from the street, a rigid slab insulation made of light concrete, foam glass, fiberboard in combination with weather-resistant and durable cladding (asbestos cement sheets, boards, etc.) is used. The option of wall insulation from the outside is effective only if there is no access of cold air to the contact zone of the bearing layer with the insulation layer. To insulate the external walls from the side of the room, use a semi-rigid plate insulation (reed, straw, mineral wool, etc.), which is located close to the surface of the first or with the formation of an air layer, a thickness of 16 - 25 mm - "relative". Plates "on the relate" are attached to the wall with metal zigzag brackets or nailed to wooden antiseptic slats. The open surface of the insulation layer is covered with sheets of dry plaster. Between them and the insulation layer, a vapor barrier layer of glassine, plastic film, metal foil, etc.

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