Sealing wooden houses: warm seam. How to make a deformation seam for an extension to a house Warm seam on a wooden house application technology

Sealant for wood "Warm joint" can become the basis of the thermal insulation protection of the building. Undoubtedly, there are other ways, but this one is the most convenient. If you have begun to think about the insulation of your home, then you should resort to this particular technology. Making a comparison with traditional system thermal insulation of interventional gaps, where hemp, jute or flax insulation is used, it is worth noting that filling the cracks in the interventional space with a sealant increases the thermal resistance of the walls and reduces heat loss. If we are talking about natural heaters, then they are able to pass inside cold air, which significantly reduces the heat resistance of log walls.

Consumer feedback on the effect

Sealant for wood "Warm seam" has many advantages. According to users, with its help you can get a comfortable indoor climate. Such thermal insulation makes the temperature and humidity conditions optimal, while saving energy, because there is no heat leakage from the interventional gaps. Home heating costs are minimal.

Owners of private wooden houses they say that after carrying out work on thermal insulation according to the described technology, drafts disappear, log walls are not blown through during cold and damp weather. You can count on the material not being damaged by bio-organisms. The gaps are maximally compacted, mold no longer forms in them, and insects do not penetrate inside.

If you use Warm Seam Wood Sealant, you can save money. According to buyers, you no longer have to invest them additionally, which is required with periodic caulking. Among other things, in the end you will get quite attractive walls, the seams of which will match the tone of the wood.

Reviews of the benefits of "Warm Seam" over caulking

Previously, the insulation of wooden houses was quite often carried out using the caulking method, today this technology replaced by a system called "Warm Seam". The latter technique has many advantages. For example, caulking walls is quite laborious, and it is necessary to start this no earlier than a year after the completion of construction. According to the owners of private houses, this cannot be called convenient. Among other things, it will be necessary to repeat the caulking process regularly, since flax and moss are pulled apart by birds, and the seams also increase under the influence of shrinkage. Modern consumers emphasize that appearance the log house after the completion of the caulking stage cannot be called attractive. Over time, the walls completely lose their aesthetic appearance.

Feedback on the characteristics of sealants for work on the "Warm seam" technology

Wood Sealant "Warm Seam" is chosen by customers for the reason that it has many advantages. According to home craftsmen, these compositions are not at all afraid of temperature changes, harmful microorganisms and mold do not appear and do not develop on their surface. As practice shows, the described sealants are not affected sun rays, and over time they do not lose their original color. According to buyers, sealants have high level adhesion to wood, they are characterized by elasticity, which is especially evident when compressing the interventional gaps. This allows you to complete these works and forget about them forever. Sealant "Warm Seam" for wood, reviews of which are only the most positive, you can apply at any time of the year. At the same time, residents will not experience inconveniences such as dust, smell or noise. The house can continue to operate. Using acrylic compounds, you can hide some and after the completion of the work, the house will acquire an aesthetic appearance.

With the use of acrylic sealants, the master has the opportunity to carry out work both outside and inside the building. According to users, the use of these compositions allows you to create original interior. This is also due to the fact that sealants can be found on sale. different shades. For example, in the assortment range you can find beige, cream, as well as white and brown shades. Sealant "Warm Seam" can be made on an acrylic-rubber base, with its help you can close the seams not only in wooden houses, but also in other places. After drying, such a composition lends itself to grinding several times, as well as subsequent staining.

Why else is it worth insulating a wooden house using the "Warm Seam" technology

If you decide to choose the Warm Seam sealant for thermal insulation work, it is recommended to read reviews about it before going to the store. This will allow you to understand that acrylic compounds can even interfere with the processes of wood decay, they will not let dampness into the house. According to users, using these formulations can be done in the shortest possible time. After applying this technique, there is no need to additionally seal the interventional seams, as well as eliminate cold bridges.

Features of the use of sealant "Neomid"

Sealant for wood "Warm seam" "Neomid" has gained popularity among consumers, its use requires compliance with certain rules. For example, before finishing application it is necessary to caulk the seams, for which jute or linen tow is used. Then, using a spatula, a sealant is applied to the surface, which makes it possible to insulate the resulting gaps in a combined way.

One of the advantages of private home ownership is the ability, if necessary, to increase usable area by attaching an additional one to the main structure. Thus, residential or utility rooms, to whom what functionality was not enough. In order for the extension to improve the living conditions of the owners, and not organize problems for them, it must be built according to existing technologies, and not on the principle of "somehow, if only it would be cheaper." Therefore, we will figure out how to properly settle down to the house, based on generally accepted methods and experience of FORUMHOUSE users.

Foundation

There are two types of foundation for an extension - a rigid hitch and an expansion joint.

rigid hitch
Such a connection is designed for non-rocky soil and is justified when erecting a heavy structure of two or more floors, but only if the main building has already settled and the village. The new foundation must be of the same type as the main one (tape, slab) and match in depth, taking into account possible shrinkage. A bunch of tapes is made by means of reinforcement, for which the foundation of the house is dug out to the full depth; in the working area, too much exposure is fraught with deformation.

Holes for reinforcement are drilled in a checkerboard pattern in the foundation web, on the basis that their length is 35 times the diameter of the rod, and the length of the reinforcement itself is twice as large as the depth of the holes. The reinforcement is driven into the holes, in the future the protruding part will be filled with concrete, a common monolith will be obtained. A bunch of plates is possible with a thickness of more than 40 cm and the presence of a protrusion of the main plate of 30 cm; for coupling, the reinforcement is beaten off and welded to the reinforcing cage of the new plate.

To perform a rigid hitch, it must be borne in mind that the flooded one, connected to the main one, must settle, ideally within a year. If it is not possible to withstand such a period, it is better to use another method.

Expansion joint
The most common type of bond is when a completely independent one is poured near the old foundation. Optimal for heaving soils for lightweight structures, the thickness of the seam is from 2 to 5 cm. In order to aesthetically connect the foundations, and
the seam at the junction remained the same along the entire length; boards pre-wrapped with polyethylene or roofing felt are used. Since the load on the base will be less, the drawdown will also be less, and the seam will allow the extension to “play” as planned without affecting the integrity of the house.

During the construction process, the joint between the walls is filled with insulation, and the seam itself is subsequently sealed with elastic means or closed with special flashings. One of the users found an interesting solution - overlays from of stainless steel, between which - a layer of corrugated rubber.

zhp FORUMHOUSE User

In principle, you can buy such a “closing” for an expansion joint, immediately insulate the distance between the walls normally, close it from the street with a “closing”, and if over time there is shrinkage, compression or stretching, the “closing” compensates for this moment. And in order to return the rubber to its previous shape, it will be possible to unscrew the screws from the left side and drill again, in new places in the bricks.

Since the foundations are not interconnected, any type can be chosen for the extension, based on the characteristics of the soil and the expected load. It can be slab (monolith or UWB), tape (MZF or to the freezing depth) or columnar (pile).

Portal users prefer joining foundations through expansion joints, as the most justified and safe way.

mfcn Moderator FORUMHOUSE

Whatever good (non-rocky) soil, if it is not a rock, then you should expect shrinkage of the foundation of the extension in relation to the main house. Accordingly, measures must be taken to ensure that these shrinkages are non-destructive to the structure and provide acceptable functional properties of the structure. Hence: annex - in fact new house next to the old lightweight design, whose walking is permissible, and violations of the horizontal floor and jamming of doors are permissible.

materials

Modern market building materials offers big choice for every taste and budget. Extensions made of foam concrete, aerated concrete, cinder block and similar large-format masonry varieties and frame structures. Frames are in the lead due to the speed of construction, relative accessibility and simplicity; in terms of energy efficiency, they are not inferior to stone buildings due to the use of heaters.

However, if possible, it is recommended to choose a material similar to the main one: wooden outbuilding to a wooden house, etc. This is especially true for houses that are not supposed to be sewn up with the same facade as the extension. If you plan to use siding or similar cladding, the choice is not limited.

Wall tie options

An extension to the house can have four walls or three, then the role of the fourth plays outer wall Houses. Four walls are relevant in extensions made of masonry materials, a bunch of walls is not required, and compliance with the masonry level gives even seam. The presence of a layer of insulation between the walls allows the use of thinner blocks for the adjoining wall. At frame construction sliding ligaments are used: two vertical beams are stuffed onto the wall, between which they start vertical bar extensions.

Connecting beams in the annex

When the extension is assembled from profiled or glued beams or logs, the walls are connected to the house either with metal brackets or with special galvanized corners with a shelf of 63 mm or more.
The corners are planted on self-tapping screws, leaving a small gap for shrinkage. The seam in both cases is closed with a flashing or platband. Also, the docking of the beams in the extension is carried out by means of a tenon-groove system, the grooves are selected in the load-bearing wall, the tenon is cut on the built-in segments.

Roof

The extension is being built under common roof when a rigid connection is made, if an expansion joint is selected, it is easier to cover the building separately, sealing the junction. Depending on the roofing material, the seam is closed with a stainless steel apron, 30 cm wide or with a special decorative element.

Rigid connection to the house from a bar.

mfcn

The shrinkage of the extension in relation to the main house imposes certain restrictions on the arrangement of the roof. Therefore, in practice, making an extension with a roof such as a continuation of the existing one should be deliberate and reasonable.

Functional

As with the construction of a house, before erecting an extension, it is necessary to determine in advance the functionality, since different purposes require appropriate construction manipulations. If it is supposed to make living rooms, enhanced insulation is necessary. For the boiler room, bathroom or kitchen, communications are immediately laid. It's easier to change your mind and close a couple plastic pipes into the wall than to decide that another bathroom is more needed and peck at a freshly built one.

Legalization

Before construction capital extension permission must be obtained. Within the city limits, this is done by the Department of Architecture and Urban Planning, in rural settlements- administration. You can build without papers, but then when you try to sell, bequeath or donate a house with an extension, you still have to draw up documents, but it’s more difficult, through the courts. In the event of a confrontation with the neighbors, they can sue the self-builder and insist on the demolition.

For anyone planning an extension, it is useful to study the topic on the forum. The user experience of our portal in the topic is also interesting. The article will help determine the type of foundation under future design. And our video will teach you

And everything would be fine, yeah "in a barrel of honey, there is a fly in the ointment" . And it is environmentally friendly, it is beautiful, and even warm. But, here are the seams ... Indeed, the seams - weakness in a wooden house. We have already spoken separately. But, in recent years, technology has been increasingly used warm seam for wooden houses made by hand. What is her role? Here's what experts from one company say:

« Proper insulation of the log house begins with caulking. Sealant is not a replacement for her, but only a good addition. The insulation must be laid flush, Valiterm laid, and then sealed. The goal during isolation is to fill the entire interventional space. But, it's important to do it right. The sealant must not come into contact with the insulation. Otherwise it will crack over time.

So, we have a few questions and the first of them: what is the Warm seam technology?

The usual methods of thermal insulation of seams in a wooden house have 3 significant drawbacks:

• Let moisture and insects into the room;
• Require regular replacement;
• Spread by birds.

How to improve the insulation system of intervention space? For this, the "Warm Seam" system was developed.

Its essence is that a special sealant is applied over the insulation and a special cord at the junction of the logs. It is beautifully smoothed and after painting (even colorless) it becomes invisible. However, it protects the seams well from blowing and moisture.

Required materials and choice of sealant

How much and what will it take to carry out such work with your own hands? Given the above quote, we will take into account that the initial insulation of the seams has already been made. So, from the materials we need:

• Acrylic sealant for wood;
• Heat insulating cord.

From tools:

• Pistol (manual, but better pneumatic);
• 2 spatulas (small - for the size of the seam and large for the convenience of removing excess from the first one);
• Brush (to remove excess);
• Possibly: sponge and spray bottle (water sprayer)

“If you work on large volumes (from 200 meters), use an air gun. The hand will get tired much less.

Arkady Krasnov, "Siberian wooden houses".

Now it remains only to choose a sealant. First of all, the sealant can be sold in buckets, usually 15-25 kg and tubes of 600 ml.

As you probably guessed, large volumes buying is always cheaper.

Like with Coca-Cola - than more bottle, the lower the price per liter.

Although, the use of buckets is not so convenient in the process of work, and, of course, longer.

The sealant also differs in color, you need to choose the right one for painting.

• Eurotex;
• neomid;
• Remmers.

There are many more options, but most people choose one of the three above. As usual, American or German ones are higher in quality and price than domestic ones.

Price

As already mentioned, the tuba is more expensive. One tube of 600 ml is enough, on average, for 4-6 linear meters. It depends, of course, on the thickness and unevenness of the seam, as well as the experience of the finisher. The cost of a German Remmers tube, for example, is 430 rubles. In this case, in the best scenario, the cost of 1 meter of the seam will be 72 rubles. A bucket of Eurotex 25 kg costs approximately 7,300 rubles. When using such a sealant, the cost of one meter will be 28 rubles.

By the way, a warm seam for wooden house can be ordered from a contractor. However, the price of such a service will cost 150-170 rubles per running meter. For a day, a novice specialist can do 50-200 meters. (Much depends on the size / evenness of the seams and personal abilities).

If you decide to apply it yourself or check the masters “for lice”, the sealant application technology is described below.

Application technology

The technology, in fact, consists of 6 main stages:

• Laying a heat-insulating cord. Its task is to fill the mezhventsovoe space. It is pointless to use a more expensive sealant for this, and it is rather problematic to fill the space with it. It is reasonable to use sealant as the top, fixing layer.

• Application of sealant with a gun. For this purpose, the tube is inserted into the cavity of the gun (or the sealant is drawn directly from the bucket). After that, the spout is cut off at 45 degrees, to the size of the seam. The sealant is then applied polyurethane foam. Some installers use adhesive tape, sticking it as a frame for the borders of the seam. This allows you not to stain the timber, and after application to collect the excess. Once applied, the adhesive peels off almost immediately. However, after gaining experience, you are unlikely to need such a procedure. Professionals apply "Warm Seam" without adhesive tape on a footage from 1.5 to 2 m in one pass and very evenly.

• If excess sealant gets on the crowns, immediately remove them with a damp cloth.

• Dampen a small brush and use it to smooth out the seam layer.

• If there is a lot of excess, a small spatula can be used to remove them.

• Now it remains only to walk along the seam with a slightly damp cloth for final alignment.

Some use a sponge and a sprayer for this purpose. In this case, the seam becomes glossy.

Corners and cuts

Difficulty, especially in the first experiment, is corners and overcuts. In fact, the sealing of such areas is carried out in the same way as smooth seams.

• Measure and cut in advance pieces of cord of the desired length;
• Lay the cord (you can use a spatula or brush to tuck it in);
• Apply sealant;
• Carry out the alignment procedure described above.

It can be seen that in general, the application process is not particularly complicated. Although, making a warm seam for wooden houses is a very tedious job. So be patient and / or reliable "Russian way".

Below in a series of photos you can see the whole process step by step.

And a step by step video:

Technology FAQ

But will the sealant be useful if it is applied to already caulked seams?

Certainly. The answer has already been given at the beginning of the article. Correct application warm seam and provides for caulking, laying Valiterm and cord. However, it is important that the insulation does not come into contact with the sealant.

Remove smudges immediately after leveling or after drying?

To avoid leaving traces, it is better to remove immediately, but carefully so as not to touch the sealant.
Which seal to choose, inside or outside?

The short answer is that both types are needed. Outdoor, protect the house from moisture, insects and blowing. External sealing also serves as waterproofing. However, you need to protect the seams inside. For example, from moisture formed in the room itself.

Can it be applied in winter?

It depends on the type of sealant. For example, Accent-136 can be used at temperatures from -10 degrees. There are also more "heat-loving" analogues.

Sealant is used for sealing built-in elements made of plastic, metal, wood, door jambs, joining joints of wood and plastic window frames, for sealing cracks up to 5 cm wide. Sealant is used both for external and for internal works. It can be used to repair the facade, masonry, as well as various wooden and plastered surfaces. It is mainly used for wooden houses. They can process materials with reduced strength, including foam concrete and materials on plaster base. The main scope of application is the Warm Seam technology. With the help of this technology, it is possible to effectively eliminate the heat loss of wooden houses by blocking the outflow of heat through cracks, cracks and gaps between the logs. The use of sealant for these purposes allows you to protect the house from drafts, cold, mold and other common problems.

Special sealants for wood of the Accent and Terma-Chink "Warm Seam" line are based on acrylic polymers, due to which they have higher performance than their counterparts. They have high elasticity, resilience, created on water based and do not contain solvents, so it can be used indoors. After drying, the surface can be painted with water-dispersion paints, enamels, wood varnishes. A guarantee of quality and durability is the use of a range of materials from one manufacturer.

Application temperature from +5°С to +35°С
Operating temperature from -40°С to +70°С

The sealant is not recommended for use at temperatures below +5°C and humidity over 80%, since the drying time of the sealant increases dramatically, and due to the evaporation of water from its surface, it cools below the ambient temperature and it will be subject to the problem of moisture condensation from the surrounding air on its surface, which can cause the unformed film to be washed off. It is also not recommended to apply the material in the rain (even drizzling). At high humidity, the drying time of the sealant increases, and drops of water can cause the unformed film to be washed off.

In hot and dry weather, it is worth paying attention to the contact of the sealant with the base (wood temperature can exceed + 35 ° C), which can be disturbed by the rapid drying of the material due to the absorption of water by the wall surface. Complete polymer film does not have time to form and the adhesion of the sealant to the surface is reduced. In this case, the base should be primed or moistened with water before processing to reduce the absorbency of the wall surface.

Do not apply in direct sunlight, use protective canopies. Direct sunlight accelerates the formation of a dense surface film and can cause the formation of bubbles and blisters on the surface due to the evaporation of water from the depth of the applied sealant layer or air trapped in the layer when sealant is taken from a bucket. A protective canopy is erected from the roof to the ground to shade the treated wall surface, leaving space for air to circulate freely along the wall. Wall shading time is 3-5 days.

If the house is very hot inside (heating) and not ventilated, then the air pressure inside the house is higher than outside, which can also lead to the formation of bubbles on the surface of the sealant applied from the outside.

Application technology

Before applying the sealant (the sealant is applied at a stable average daily temperature of at least +5 ° C), the surface should be cleaned of tar, dust, oils and other contaminants, it should be noted that it is better to apply the sealant a year and a half after the construction of the log house, when the house sags enough. Sealing inside the house under the same conditions, but the house must stand under heating for at least 2 months at sub-zero temperatures outside the house.

When applying in an older home, check the wood for signs of decay and rot. Remove or replace damaged wood. It is recommended to remove insufficiently bonded and fragile coatings, adhesion can be checked with a trellis notch. When testing coatings on wood or similar material, the notches are made at an angle of 45° to the grain direction of the material. The notch must completely cut through the coating to reach the base), the distance between parallel notches is 1-2 mm. Repeat this operation at an angle of 90° to the original cuts to obtain a lattice (at least 6x6 cuts). When testing coatings applied to hard and wood surfaces to be painted, a duct tape. To check the density of contact with the coating, press the tape with a fingertip or fingernail. The color of the coating seen through the tape is an indication of the full contact of the tape with the coating. 5 minutes after gluing the tape, it is removed by holding the free end and gently tearing it off in 0.5-1.0 s at an angle of approximately 60°. If the area of ​​delaminations (adhered to the adhesive layer of the tape) exceeds 10% of the grid area, the coating is considered unsuitable and must be removed. However, it should be noted that when applying sealant to old coatings from another manufacturer, we cannot guarantee the durability of such a combination.

Surfaces that absorb water quickly should be treated with a deep penetration primer to reduce/even out absorbency. The primer can also be prepared from sealant by diluting it with water in a ratio of 1:1.

The edges of the seam must be dried (small humidity is allowed) and dedusted. Too deep seams should be pre-laid with polyethylene foam cord high pressure, fixing it inside by caulking, special glue or nails. The polyethylene foam cord is used for the correct configuration of the warm seam. After drying, the sealant sticks to the top and bottom logs, but does not stick to the cord. As a result, an elastic membrane is formed.

Joints must be completely filled during application. The presence of voids is not allowed. The optimal layer thickness is 4-6 mm, it is not recommended to apply a thicker layer of 8-10 mm due to the long drying time (more than 4 weeks). After applying the sealant, it must be immediately (15-30 minutes from the moment of application) smoothed / leveled with a spatula, and smoothness of the resulting seam can be given with a spatula moistened with water or a wet brush with soft bristles.

Excess sealant, immediately after application, can be easily removed with a wet cloth. You can glue the edges of the seam with masking tape, which is removed after applying and leveling the sealant.

Until the sealant dries, the seam must be protected from water and direct sunlight. Complete polymerization occurs within a week (at a temperature of 20 ° C and a humidity of 60%), however, the sealant begins to perform its functions already in the course of solidification.

Good day. Need help with an extension. We started building the walls of the house from expanded clay concrete blocks, and realized that there was not enough space in the living room. There was an idea to add a warm extension and combine it with the room, but there are many nuances, since separate rooms It is possible to complete the principle if desired, but is it possible to unite the space? the existing foundation is a monolithic reinforced concrete with a plinth and a pillow. So far, I'm thinking about the pile-grillage foundation of the extension, not to connect it with the main one, to make an expansion joint. The walls are also from KBB, only 400mm. An extension with the letter P. But how much can a new foundation play relative to the old one? It turns out that you need to make two separate floor screeds in the old and new parts living room? How to perform a joint of two foundations and walls in this case? What other things might come up? I would appreciate your comments and help. I am attaching drawings to help you understand the situation.

For information: we did not do geology, but the soil is not problematic, the site is located on a hill, ground water deep. There are small layers of clay, but not much. Concerns about issues such as:
1. I plan to dock the foundations through an oil-filled board, but the question is that the blocks on the existing foundation lie with a protrusion of 10 cm outward, and if you dock a new grillage close to the foundation, will it damage these blocks in the spring if it suddenly starts to rise? How to perform insulation so that the floor at the junction of the foundations does not freeze through?
2. Is it enough for a U-shaped extension of the same U-shaped foundation, or is it necessary to fill in four walls? (deformation seam in this case?)
3. How to make a quality wall joint? Recommended tow, elastic sealant, regular foam pour .. What do you advise? Maxim.

Thanks for the detailed information, Max. Detailed presentation technical side The question was very helpful for our experts to make recommendations for you. We hope our answer is helpful.

In order:

1. "How to make a joint for joining two foundations?"

Let's start with the foundation design. There are two design options making additions to the house:

Option 1

Rigidly connect the extension to the main part of the building. For this, the foundation of the extension must have a structure similar to the existing one, that is, it must be tape with sufficient depth. At a minimum, the base pad of the new foundation should be located below the freezing depth of the soil. In this case, both the foundation and the walls can be connected to each other with reinforcement, having hammered it in advance drilled holes within existing walls. In this case, the expansion joint is not needed, the formwork for strip foundation can be installed close to the existing one, expanded clay concrete blocks lay end-to-end on the solution. It would be desirable to cut a recess in the existing blocks at least 10 cm in a couple of places along the height and lay the laying of new walls there. The difference in the height of both parts of the building is small, the loads will not differ very much. With a rigid docking of the extension with the house, it is necessary to pay maximum attention to the reliability of the foundation, to exclude its subsidence. You write that “the soil is not problematic”, this is good. Under the tape, you need to build a reinforced support pad about 20 cm high, 10-15 cm wider than the tape on both sides. The soil under the pillow must have its original density, bulk soil is not allowed. We recommend making a crushed stone (not gravel) bedding about 15 cm thick and compacting it properly. Such a solution will make it possible to make a general floor screed, without worrying about the expansion joint, there will also be no seams in the walls.

This video shows how to rigidly tie the parts of the foundation of a building that are being erected into different time

Option 2

The construction of the foundation of the extension differs markedly from the main volume; an expansion joint is made between them. Both parts of the building can have noticeably different shrinkage and this will not cause damage to the structure. This solution is optimal when constructing a pile-grillage foundation, which you probably chose because of its cost-effectiveness. Piles, having a smaller area of ​​support compared to the pillow of the tape, will sink deeper than the tape structure.

Please note: when building piles, try to ensure as much as possible large area their support on the ground, this minimizes the subsidence of the foundation of the extension. For drilling wells for piles, it is advisable to use a TISE drill, in many cities their rental is organized.

The “trick” of the TISE drill is that, having reached the ground support mark, you can expand additional blades and significantly increase the diameter of the well. Let's get support large area, the section of the pile itself does not increase.

How to fill the expansion joint in the foundation? Since the dimensions of the house are small, thermal deformations characteristic of large buildings, can be neglected. The house is small, with a well-made foundation of the extension, only its vertical displacement is possible. There is no need for a wide expansion joint, it is sedimentary, not temperature. If the formwork of the existing foundation is done carefully, its surface is even and strictly vertical, when topping up the foundation between the existing and new parts, you can lay any thin material, which will not interfere with vertical movement. For example, a strip of roll bituminous waterproofing: roofing felt or its modern counterpart.

In the sedimentary expansion joint of the foundation, in contrast to the temperature joint, only vertical displacements are possible. Its thickness does not matter, it is only necessary to ensure the possibility of settling part of the building. For this, an ordinary ruberoid is suitable.

If the surface of the existing foundation is uneven, it will be necessary to fill the seam with an elastic material, the thickness of which will be sufficient to compensate for the unevenness. Neither a tarred board nor tow should be used, because it is organic matter that will quickly collapse in the ground. In addition, the board will swell, jamming the seam. And how to fill the entire depth of the joint with tow, we can’t even imagine. Today there is a sufficient number of durable, non-rotten and non-absorbent sheet elastic materials. For example, foamed polyethylene. Or expanded polystyrene, on sale there are sheets with a thickness of 1 to 5 cm, the size is a multiple of a centimeter. The thickness should be chosen depending on the degree of unevenness of the foundation. If necessary, if there are significant irregularities on the existing foundation or the slope is large, the expanded polystyrene sheet can be cut with a knife or melted building hair dryer. The smooth side of the sheet should be turned towards the new foundation, trying to install it vertically.

One of the options for performing an expansion joint of the foundation and walls. The two parts of the building are separated from each other by a sheet thermal insulation material. In your case, it is enough to use polyethylene foam no thinner than 4 mm or extruded polystyrene foam 10 mm

Thus, the joint between the two parts of the foundation is filled with sheet or roll relatively soft material. The sealant that you are advised is to fill the outer part of the joint to a depth of 1-1.5 cm. The function of the sealant is to seal the joint, sorry for the tautology. If the gap is wide enough, it can be filled and construction foam. But after the excess foam is cut off, it should also be covered with a layer of sealant. Suitable for any type of foundation construction sealant other than acrylic.

1. “Is it enough ... a U-shaped foundation, or do you need to fill in four walls?”

Probably, you meant the following: is it enough to build a foundation only along the outer contour of the extension, or does it need to be closed, the bay also has a grillage around the entire perimeter, including near the existing part of the building? If we guessed the essence of the question, we answer: enough, not necessary. The foundation serves to support bearing walls, only under them it makes sense to build it. Your drawing shows a new pile-grillage foundation and, along the existing one, either a monolithic or a prefabricated reinforced concrete slab rests on it. But two hollow-core slabs with a length of 5380 mm can be perfectly supported on two short extension walls. And for monolithic floor make one or two intermediate pile supports instead of a full-fledged grillage.

Please note: the piles closest to the existing part of the building supporting the grillage should be located as close as possible to the old foundation. The distance is the minimum that the TISE drill will allow, taking into account its expansion under the support platform.

1. “How to make a high-quality wall joint?”

Let's rephrase your question: how to fill the expansion joint in the wall? We use the same principles as in the construction of the foundation: roll / sheet / slab material inside and sealant outside. We hope that the walls of the house are quite even, so thin (2-3 mm) polyethylene foam, cork sheet or other warm non-rotting material can be laid between the blocks. From the inside the seam "seal" acrylic sealant, plaster and putty will lie well on it. Outside, if you plaster the wall - also with acrylic, if you leave the blocks without finishing - with silicone, it can be matched to the color of the walls.

There are also a number of special materials for filling expansion joints. Among them, we especially note swelling cords made of hydrophilic rubber (for walls) and swelling bentonite profiles (for foundations). Cords are intended to fill the outer part of the joint, they are used instead of sealant. These are excellent professional materials, specially designed for sealing joints. However, they are quite expensive and are not sold in retail chains. You will have to look for a supplier company, but there are not so many of them. There will be an opportunity - use them, no - simpler and cheaper solutions described above are also suitable for your case. Another type of special materials for seams is overlays. They are useful if, as a result of deformations, the seam diverges. The patch closes the gap. In your case, we do not recommend installing such an overlay. If the seam still breaks, it is better to refill it with sealant.

You can (and would be nice) to use special cords and pads to fill the seams. But this is quite troublesome, expensive and certainly justifies itself in the construction of large buildings. Do you have small house and such a serious approach is optional

You write "blocks on an existing foundation lie with a protrusion of 10 cm outward." It's not a problem. Make a horizontal expansion joint on this 10 cm section. If you deepen the foundation of the extension, as expected, below the freezing depth, it will not rise after the winter. For the next season, check the condition of the seam, if necessary, renew the sealant, if a noticeable gap forms, fill it with construction foam.

It makes sense to take care to exclude horizontal displacement of the extension walls adjacent to the main building. The dimensions of the house are small, such deformation is unlikely to occur, but if you decide to give the structure additional reliability, you can reinforce them in the upper part of the wall joint. Fix the reinforcement rigidly in the existing wall, and place it in the extension in a vertical gate

When installing a block wall in one of the upper blocks, you can cut a vertical streak by inserting reinforcement there, which is rigidly fixed in the wall of the main building. This will eliminate horizontal displacements, but will not prevent vertical ones.

1. “So, you need to make two separate floor screeds in the old and new parts of the living room?”

If the foundation will be made according to option 1 (rigidly connected and without an expansion joint), and the floor in the extension is located on reinforced concrete slab, as in the main part of the house, there is no need for an expansion joint in the floor. You can monolithic a common screed. In other cases, an expansion joint should be made in the floor. And it doesn’t matter if the new floor rests on the slab, or you decide, having saved money, to build it on the ground, making a backfill in the extension. The seam must necessarily penetrate through the entire floor structure from top to bottom. Including coverage. If it is a tile, try to lay it out in such a way that the seams in the tile coincide with the deformation. It doesn’t work - you have to cut the seam right in the tile and fill it silicone sealant matched in color. AT massive parquet or floor boards, the seam can also be filled with sealant. In floating floors (laminate, parquet board) you will have to close the gap with an overlay strip.

There are also quite expensive special neat profiles for devices in floors. expansion joints. The illustration shows a profile for a tile, the middle part of which is made of a split elastic material.

1. "What other moments might come up?"

Be sure to "float" the roof. From below, the rafters will rest on the wall of the extension. And from above, based on the drawings you sent - on existing wall Houses. If you complete the foundation according to the second option, when the extension sags, the mark of the lower support will go down. If the rafter legs are fixed rigidly, with noticeable drawdowns, annoying troubles are possible: top mount or at the bottom the wall of the extension will be pulled inward. To avoid this, it is necessary to allow free movement of the lower support. This issue is completely solved by the sliding structure of supporting the rafter legs.

sliding support for rafter leg- a simple device that will allow you to articulate the rafters and avoid problems with the roof of the extension in the future