How to make an extension to a house without a foundation. Wouldn't an extension be possible without a foundation? If the house is made of brick or wood

Is it true that the foundation for an extension differs from the main one, what are its features? Many people are looking for the answer to this question, because when adding additional rooms to an existing house, you want these rooms to also have a reliable foundation. The most important tips and we have collected instructions in this article.

Everyone knows what role the skeleton plays in the human body; similar functions are assigned to the foundation. In fact, this is the basis that is responsible for the reliability and durability of the building. Also, it is the foundation that ensures warmth and dryness in the room. If the base is of poor quality or does not suit specific conditions, then dampness will appear inside, the floors may become deformed and completely deteriorate. It also levels the ground level and prevents carcinogenic gas from entering the living room from the soil.

Extension base

The choice of foundation should be treated with particular care. After all, it is necessary that it can easily withstand loads and correspond to the type of soil. At the same time, there is no need to overdo it, for example, if you can pour a strip or column foundation, then there is no point in replacing these more simple options complex monolithic base. Firstly, it is too expensive and not worth the investment. Secondly, the first ones are much easier to perform and you can do them with your own hands even without outside help, but to lay concrete slab There is no way you can do it on your own.

It is mainly built from stone or concrete, but there are also wooden structures. If the construction is lightweight, then you can give preference to a shallow foundation located above the freezing point. But most often its depth should be below this level. According to its purpose, it is divided into load-bearing and combined. The latter, in addition to standard load-bearing functions, must also provide seismic protection. There is also a special type, which includes “swinging” and “floating” foundations, their pressure corresponds to the pressure of the excavated soil.

Which types of base to choose from?

In this paragraph, we will consider what types the foundation for an extension is divided into. Tape can rightfully be called universal, because it is perfect for both heavy and lightweight structures. It is located only under external and external load-bearing walls. It is mainly poured from concrete; to make the structure more reliable, it should be reinforced with iron rods. If you are going to make this type of base with your own hands, then it is better to give preference to the prefabricated version. The disadvantages include high cost.

Universal strip foundation

But the columnar one, on the contrary, refers to budget options. But it is advisable to use it only if we are talking about lightweight structures, for example, you need to tie a frame extension to wooden house. The supports are special pillars located at intervals of 1.5 to 3 meters. These pillars must be placed at the intersection load-bearing walls. It is best to make such elements from brick or reinforced concrete, but larch beams can also be used. However, such supports are expensive, and wood is not durable.

If you are going to build a rather massive building, and weak soil predominates, then you should give preference to the pile type of foundation. This design consists of supports connected by means of a strapping beam.

How can two foundations be connected?

The foundation for the extension can be rigidly adjacent to the base of the housing, resulting in the formation of a single structure. This solution is relevant if the site has a weak or non-heaving type of soil. You should also give preference to this option when you are going to make an extension of several floors and want to connect it with the main housing through one roof.

If the base is a slab, then additional housing should also be poured monolithic foundation. In this case, it is necessary that its thickness is at least 400 mm or that the base of the residential building has protrusions. In this case, you can weld the slab reinforcement to the frame of the new foundation. In addition, if you wish, you can do everything yourself.

Monolithic foundation slab

The “tape-to-tape” connection assumes the presence of a sand cushion and reinforcement with a longitudinal slot. Metal rods are driven into specially prepared holes in the base of the house and form a frame for the new foundation. Next, the joint is made using a release about 40 cm long.

You can also build a separate foundation for an extension, which will be located in close proximity to the house. A sheet of roofing material should be placed between the two bases. This material acts as an excellent waterproofer; you can also place a layer of thermal insulation or get by with simple tow. In this case, it is very important that this layer allows the new base not to collect water during precipitation and not damage the foundation of the house. On the outside, special decorative overlays are fixed to the wall to cover the seam.

Laying the foundation - we do it according to science

Now let's move on to the practical part and look at how to make a foundation for an extension with your own hands. This detailed instructions will help you save on the services of a specialist, because it is designed for self-execution construction work.

Building a foundation for an extension with your own hands

How to make a foundation for an extension to a house - step-by-step diagram

Step 1: Selecting a Base

The new foundation must fully correspond to the type of the previous foundation. In addition, the load and soil type are taken into account. For example, if we are talking about a massive extension to a brick house, then it is necessary to lay a strip or make a pile foundation. But if the additional room is adjacent to a wooden dwelling, then it is possible to get by with a cheaper columnar option.

Step 2: Calculations

Regardless of whether you choose a rigid connection type or a separate foundation, the depth and width, as well as the dimensions of the foundation pillars, if any, should be the same as those of the foundation of the house. Determining these parameters is quite simple. It is necessary to dig a hole next to the wall of the house and measure the dimensions of the base. If there should be no questions about how to measure the depth of the structure, then to measure the width, you should take a rod, bend one of its edges 90° and insert it in a horizontal position under the foundation. Then we turn the rod until its bent part rests against reverse side. After this, you need to make a mark on the rod and pull it out. By measuring the distance from the hook to the mark, we know the width.

Step 3: Preparatory work

Before pouring the foundation for the extension, it is necessary to carry out preparatory work. If you decide to give preference to a rigid connection, then we dig a trench of the given dimensions and drill holes in the existing base. Moreover, their diameter must exceed the thickness of the reinforcement. Metal rods should also be prepared. It is necessary to make a longitudinal slot at their end and insert a special wedging insert into it.

Step 4: Frame Formation

We drive the reinforcement with wedges into the prepared holes. The number of rods is taken at the rate of 20 pieces per square. In this way, the frame of the future foundation is formed. To ensure a reliable connection of the following parts, it is necessary to leave the edges of the reinforcement about 300 mm long, which will subsequently need to be welded.

Step 5: Installation of formwork

Now you will need wide wooden boards. We form the formwork of the given dimensions. We securely fix its walls with supports, earth, cinder block, etc. You can close inner part formwork with polyethylene. The latter is especially true if you are pouring only part of the foundation and you will have to reuse these boards.

Step 6: Pouring the Mortar

We prepare a mixture of cement, sand, crushed stone and water. It is very important to keep the proportions correctly. For example, for M300 you can take 10 kg of cement, 30 kg of sand, 40 kg of crushed stone, mix everything well and fill it with 40 liters of water. If the concrete is too dense, you should dilute it with liquid, but only add it in small parts so as not to spoil the solution. We pour concrete into the formwork and wait several days until it completely hardens. We moisten it periodically, otherwise cracks may appear.

Step 7: Formation of a columnar foundation

Making such a foundation is important when a lightweight extension is adjacent to a wooden house. We drill holes so that they are below the freezing level of the soil. We form a sand cushion and install fiberglass reinforcement. This material has excellent properties and does not require additional treatment with waterproofing compounds. Formwork of specified dimensions is also formed and filled with concrete. This foundation for an extension is the easiest to implement, and everyone can create it with their own hands.

Step 8: Construction of a separate foundation

But when the number of storeys of the main and adjacent housing is different, then a separate foundation should be made in close proximity to the previous one. The distance between the two bases is from 2 to 5 cm, depending on the number of floors of the new room. The higher it is, the wider the seam is selected. Let's fill this gap thermal insulation materials or tow. Then a special decorative overlay is attached to the wall of the home. It is very important to correctly mark the base. To do this, we pull the cord onto the pegs around the perimeter of the future site and check whether the diagonals are equal. If a heaving type of soil predominates on the site, then the floor of the extension must be made so that it is not lower than the flooring of the main housing by the amount of possible deformations.

Sooner or later, in almost any household there is a need for additional living and working space. When planning the construction of new buildings by connecting to an existing main house, it is important to take into account all the loads and the effect of inevitable shrinkage on both parts of the structure. Before starting construction of any such structure, it is necessary to equip the foundation for the extension. In case of errors during construction, deviation and distortion of the structure may occur. That's why the most important stage The process will be designing and installing the foundation for the future premises.

We must not forget that the implementation of any large projects requires coordination with regulatory organizations. Building an extension to an existing building is quite a responsible task, just like building a full-fledged house. An accurate calculation and a well-designed action plan are required. A certain amount of professional tools are involved. Most likely, you will have to get help. And yet, subject to the technological process, it is possible to do it yourself, without involving third-party specialists.

Preliminary work

In order to determine the type and dimensions of the building’s foundation, a pit of 100×150 cm or 100×100 cm is dug near any wall. The strip foundation is measured in width and height. For columnar, the parameters of the pillars and the depth of their laying are important. This issue should be given sufficient attention, since marking the foundation is one of the most important stages.

The size of the base is measured using a steel rod, the end of which is bent 90°. The rod is placed under the sole, placing the bent part strictly horizontally. By turning it, they detect the moment when the curved edge rests against the wall from the inside, and put a mark on the metal. The distance from the bend to the mark, measured after removing the rod, will correspond to the width of the tape.

At the time of pit development, the type of soil on the site is also determined. The data obtained will determine which foundation to choose.

If you have a design for an old house, no preliminary measurements are required. But you should definitely find out the geological characteristics. Careful planning for initial stage work taking into account all the features of the terrain will allow you to avoid mistakes.

After the analysis, you should decide what design the future foundation should have. There are several types of them:

columnar;
strip reinforced concrete;
pile and pile-screw.

With rare exceptions, the extension has the same type of foundation as the house. This ensures the reliability of the entire structure.

Foundation rules

In the process of joining two foundations, you cannot dig up the entire perimeter at the same time if it is more than 3 meters. This will make the building less stable.
When the structure is located on a concrete slab, another slab is poured nearby. Similar ones are attached to a pile, strip or column foundation. The difference in characteristics will create excessive stress on the existing foundation, which will lead to greater shrinkage and sometimes collapse of the entire structure.
The depth of the foundation for the extension is necessarily planned to be somewhat less than for the main building. This creates space for future shrinkage.
Further work is carried out only after the poured concrete has settled. This usually takes about six months.
Coupling can be done in the following ways:

Separate installation and subsequent formation of an expansion joint;
Rigid connection with laying of general reinforcement.

To correctly pour the foundation for an extension, you need an error-free calculation. The choice of communication method depends on the type of land in the area. The dimensions of the attached structure also influence this.

Hard connection

This method is used in the following cases:

on non-heaving and slightly heaving soils;
if there is a shallow strip foundation, the base part of which forms a single whole with it;
when the shrinkage of the building is predictable;
when building an extension of several floors under one roof with the main house.

In the case of a columnar version, the reinforcement is mounted on the base, if it is of sufficient size. When the length is not enough, it is more logical to choose another method. Violation of this rule is fraught with cracks and instability.

Where to start connecting tape samples:

A ditch is dug to the required size. A layer of sand is poured onto the bottom to ensure stability.
Holes are drilled in the foundation. Each next row is drilled offset from the previous one.
Metal rods with a longitudinal slot at the end are driven into the holes, into which wedging wooden inserts are inserted.
Using protruding sections of reinforcement, the foundation for the extension is formed.
After the frame is ready, concrete is poured.
Further work can continue only after the structure has settled. This standard is observed for all filling options.

A slab foundation is connected in this way only if its thickness is more than 400 mm. The possibility remains the same when the slab protrudes beyond the base of the house. The protrusion must be more than 300 mm. The reinforcement is stripped and welded to metal frame foundations of the extension. Such protrusions are often found in buildings made of foam blocks.

Separate construction

When working with a tape base, the area is marked and a ditch about 600 mm deep is dug under the tape. The bottom of the trench is filled with sand or gravel to create a cushion. The next step is to install durable formwork according to the specified dimensions. Reinforcement is made with metal rods and poured cement mortar. A free-standing foundation for an extension to a house guarantees durability and stability of the result.

When using this method, a void is left between the wall of the old house and the foundation of the extension. The width varies from 100 to 150 mm. A layer of waterproofing and thermal insulation is laid inside. It is extremely necessary not to miss this moment and to make such an expansion joint that prevents shrinkage and protects from damage. New sole located slightly above the old one. Over time, it will settle to the same depth as the main structure. This will ensure the reliability and durability of the entire structure.

Besides strip foundation A columnar one, closely adjacent to the main building, is also used. The piles are pre-waterproofed and installed on concrete pads. Next, the harness of the required dimensions is installed. This method reduces construction time, allowing construction to continue in just a few days.

Frame extension

The foundation for a frame extension does not bear significant loads. Basically, such designs involve the use of lightweight materials. In this case, the correct solution would be to use a columnar view.

The work takes place in several steps:

holes are dug in the ground located below the freezing level;
the bottom is filled with sand and gravel mixture;
fittings are installed;
formwork installation work is being carried out;
cement mortar is laid;
the pillars can be supplemented with brickwork.

It is possible to make an extension to the house using a variety on screw piles. They are screwed into the soil and cut to the desired height. In order to increase strength and durability, concrete is poured, then the heads are welded on.

This type is characterized by speed of execution. After its installation, it is possible to proceed to the construction of a structure made of timber, OSB or plywood. The finished structure cannot be additionally weighted with any elements. You should strive for minimalism throughout the entire process.

If the house is made of brick or wood

In this case, tape variations made of reinforced concrete are used. The basis for an extension attached to a brick house is installed in the following order:

The territory is marked out according to the developed plan.
Trenches are dug below the soil freezing level.
The bottom is filled with a sand-crushed stone mixture to a height of 100-150 mm.
A rigid connection to the existing base and an expansion joint are established if necessary.
The foundation for the extension is reinforced with a frame made of reinforcement. Most often this is a design of four segments with jumpers.
The formwork is being exposed.
The concrete solution is poured.

The foundation for an extension to a wooden house is made in the same way.

The best option for constructing an extension remains the one in which it is built together with the main building. Unfortunately, this does not always work out this way. The need for expansion may arise due to family circumstances, hobbies of the owners of the house, and also depends on financial issues. It is quite possible to add a room to your house yourself if you follow all the rules and recommendations.

When various reasons If there is a need to expand the living space of a private house, then the most economical and technologically simple option is a frame extension. Its advantage is the speed of construction with your own hands with minimal skill in working with carpentry tools. Step-by-step instructions for the construction stages with photographs will help you make a useful and beautiful extension, like in the video, that will last for many years.

Purpose of the extension

To ensure that the extension does not subsequently have to be transformed, the design nuances should be considered even at the planning stage. First, decide on the purpose of the new premises.

Additional room. Construction additional room is equivalent to building a small house. All structures of a new building must be thoroughly insulated, otherwise heating such a room will be ineffective due to large heat loss. You should not skimp on waterproofing and insulating the foundation, otherwise dampness and mold on the walls will make it impossible to live in such a room.
Kitchen or bathroom. Take care of the let down engineering communications before you start building the foundation. Places where water mains or sewer pipes through the foundation it is necessary to insulate well. This is easier and cheaper to do during the construction phase.
A veranda is a lightweight extension to an open or glazed house. Is used for summer holiday. The building is not heated, so the design is extremely simple: the flooring, walls and roof are on supports. Do not forget about harmony; the veranda must be combined with the house in scale, style and materials of construction.

Selecting the base

The veranda can be attached or built-in. If the second is planned at the stage of building a house, then a separate foundation will need to be built for the first. With a gap from the wall of about 40 mm. Otherwise, during shrinkage, the monolithic base will collapse due to the different weights of the veranda and the house. Take into account the seismicity of the soil and weight future construction. A lightweight foundation built on soil prone to heaving will “lead” and the extension will move away from the house. Such a base is designed for light walls; shrinkage is inevitable under the weight of the brickwork.

For construction they use different materials: concrete, brick, stone, piles made of wood, metal or concrete. It is important to choose the right depth and type of foundation for the extension:

tape;
slab;
columnar;
pile;
pile-grillage.

In private construction, when constructing a base for a veranda, a columnar or strip structure is most often used. Let's take a closer look step by step instructions arrangement of foundations.

Strip foundation

For large and heavy buildings choose belt type grounds. It is advisable to make it from concrete in this sequence.

Important. Before erecting walls, waterproofing must be applied to the foundation. Use rolled materials or mastic.

Columnar foundation

For a light frame veranda, it is appropriate to construct a columnar base, which is made of brick, rubble stone or concrete. Or combine these materials. The holes for the pillars are dug to a depth below freezing of the soil. The step between the pillars is about 60 cm. Sequence of work:

dig square holes 50 x 50 cm. Sand is poured onto the bottom and compacted thoroughly;
lay a layer concrete mortar, and after complete setting, they begin to erect brick supports. Use a level to ensure that the masonry is strictly vertical;
a concrete support is made similarly to a strip foundation: the inside of the formwork is wrapped with waterproofing and inserted reinforced frame. The form is filled with concrete, and the top is leveled. Wet the concrete a couple of times a day to avoid cracking;

After complete drying, the formwork is removed, waterproofing is applied to the pillar, and the top is covered with several layers of roofing material - the material will protect wooden beam floors from getting wet;
the remaining voids are filled with backfill: soil mixed with crushed stone is filled in, compacted every 15 cm of the layer.

Important. The height of the foundation pillars is calculated so that the distance to the finished floor of the extension is 30 cm.

Floor: wood or concrete

A concrete or wooden floor is installed on a strip foundation. The base on pillars is obviously designed for arranging a wooden floor. Let's look at both technologies.

Construction of frame and walls

Wall structures are erected from timber, attached to previously assembled crown beams. The wall elements are assembled on a flat area in a horizontal position, and then the finished wall panel is mounted in a vertical position or each beam is connected to a beam in series. Step-by-step instruction:

On the lower beams of the harness, make a cut for vertical posts every 50 cm.
Mount the racks, securing them with corners and self-tapping screws.
Assemble the top harness.

The veranda is connected to the house by attaching a vertical beam to the wall.
Secure all posts adjacent to the house with anchor bolts.
It is better to immediately sheathe the finished “skeleton” of the veranda on the outside with plywood, boards or OSB. This will give the structure rigidity.
After constructing and insulating the roof, install windows and doors.

Ceiling and roofing

The shed type of roofing can be combined with almost any roof of the house, therefore it is the most common configuration. Let's consider it.

Insulation of walls and floors

Mineral wool is used as insulation material for walls. The mats are easily and quickly laid between the frame bars, as can be seen in the photo. When laying insulation in several layers, the mats are shifted relative to each other to prevent heat loss through the joining seams. The insulation is covered on both sides with steam and wind insulation material, which will protect the material from moisture accumulation, and the top is sheathed with finishing material. Internal walls can be sheathed with chipboard, plasterboard and covered with wallpaper or lined with clapboard. For outer wall use wood, siding or materials that match the finish of the home.

Wall pie towards external wall looks like that:

internal lining;
vapor barrier;
insulation material;

windproofing;
external cladding.

Floor on wooden joists They are insulated in the same way as walls: mineral wool is laid on the subfloor between the joists, having previously covered the boards with a waterproofing membrane. A second layer of waterproofing is laid on top of the insulation and then leveled with plywood. After this, the finished floor covering is installed.

A concrete floor can be insulated similarly to a wooden one, apply a dry screed, make concrete screed and install water or electric heating.

Do-it-yourselfers often overlook the need to comply with safety regulations. Use personal protective equipment and well-functioning, reliable tools, and then you will have only the warmest memories from the construction of the extension.

Frame extension on stilts: video

Frame extension to the house: photo

In conditions of a limited budget, when building your own home or small dacha, the initiators of the work, in most cases, do not assume that after a while there will be a need to increase the usable area. However, the family situation is changing - children grow up, grandchildren are born. We have to think about additional space. Building a separate house is not economically feasible and quite problematic. Knowing how to make a foundation for an extension to a house, you can build an additional room and combine it with the existing building.

The base of the building is the loaded part of the building structure, which perceives the reaction of the soil and proportionally distributes the loads from the mass of the structure. Knowing the premises located next to the existing building, you can build a reliable foundation for the future structure. Let's consider how to correctly complete the task, ensuring the stability and durability of the extension to the existing house.

Design features of the base for the extension

Analyzing the construction features of extensions built on foundations various designs, experts concluded that it was advisable to carry out construction activities on the same types of foundations. Different amounts of soil shrinkage, combined with differences in the foundation design, cause a decrease in the stability of the building. Deep cracks appear, which require additional costs to eliminate.

The foundation for an extension to a previously erected building may be different.

Quite often, owners of suburban real estate think about increasing their living space

The following options for joining the bases are possible:

whole. The rigid connection of the base is carried out with steel reinforcement, the ends of which are driven into the existing base, and the protruding parts are concreted into the attached base. By welding reinforcing bars into a common power circuit, a rigid frame is formed. The peculiarity of this design is an increased guarantee of the stability of the building, combined with the building by a common roof. Monolithic joints are not used on problematic soils that are deformed as a result of frost heaving;
mobile. Additional degree of freedom flexible base, consisting of separate parts, is provided with an expansion joint. It is located on the joint section and is filled with heat-insulating building materials. This design solution makes it possible to smooth out the reaction of heaving soils and dampen existing loads. The result is an increase in the stability of nearby buildings with different amounts of soil shrinkage.

A decision on a specific design option is made individually after studying the condition of the soil and performing the necessary calculations.

Activities to prepare for the work

Having chosen the type of foundation, you can begin construction. Should be prepared necessary equipment and construction tools:

bayonet and shovels for preparing a pit with small in size;

Before pouring the foundation for an extension, you should take into account its severity and soil characteristics

a small-sized excavator that facilitates digging a trench of increased length;
wooden pegs and marking cord;
concrete mixer, facilitating the preparation of increased volumes of concrete;
deep vibrator, which allows compacting the concrete mass and removing air;
the level by which the absence of slopes is controlled;
knitting device that speeds up the binding of reinforcing bars.

At the preliminary stage of construction work it is necessary:

conduct a study of soil characteristics in order to determine the optimal foundation design;
calculate the depth and width of the base, as well as determine its design features.

After completion of the preparatory activities, further work begins.

Attaching a new foundation to an existing foundation

Having assessed the possible level of soil shrinkage, you can give preference to the rigid option of combining the bases. Using steel reinforcement, it is possible to create a force circuit that is resistant to soil shifts as a result of heaving. The method of joining reinforcement frames is used on stable soils that are not subject to seasonal deformations. The reinforced concrete base in the form of a solid strip has proven itself in private construction.

Using his example, we will look at how to make a foundation for an extension to a house on our own.

The foundation for the extension should be buried to the same depth as the foundation of the house or a little higher, taking into account future shrinkage

Follow the given sequence of actions:

Remove vegetation from the work site. Trees whose roots could destroy the foundation of the building should be uprooted.
Hammer the pegs and stretch the cord between them. This is easy to do once you figure out how to mark the foundation of the extension.
Remove the soil by forming a pit of the required size. The immersion depth must correspond to the height of the existing foundation.
Anchor the steel bars into the existing base. To do this, drill holes, drive in the reinforcement and wedge it.
Assemble the formwork structure. Install the reinforcement grid and secure it firmly inside the frame.
Fill the formwork with mortar. It is not difficult to prepare concrete for the foundation for an extension to a house with your own hands.

The concrete mass will become hard within a month after pouring.

We are planning an extension to the building on screw supports

Beginner developers can build a foundation for an extension to a house with their own hands using screw supports. It is important to consider the following points:

soil characteristics. It is advisable to entrust the work of its study to experienced surveyors;
dimensions and design of screw supports. Design features piles must correspond to the type of soil.

This is the simplest and cheapest option for creating a foundation for light extensions

It’s easy to make a screw foundation for an extension to a wooden house yourself using standard tools.

Design advantages:

the possibility of constructing a foundation without extracting soil. When building a foundation, there is no need to carry out earthworks;
acceptable level of costs. By laying out the foundation for an extension on your own, you can avoid unnecessary expenses;
accelerated installation of supports. The elements are immersed in the ground within one working day;
shortening the construction cycle. By using spiral supports, walls can be erected immediately after they are screwed in place;
possibility of repeated use of piles. The screw elements are easy to dismantle for further use.

The screw support is screwed into the ground by two or three workers for 30–45 minutes, depending on the nature of the soil and the size of the support. The protruding parts are trimmed to level, and the trunks are concreted.

We join the base to the building on slabs

Construction reinforced concrete structure in the form of a slab should be performed under certain conditions:

close location aquifers. The absence of a rigid connection between the additional slab and the base of the existing structure allows it to move when the soil deforms;
weak soils characterized by low load capacity. The increased contact area prevents uneven shrinkage of the attached structure.

If the extension is made to create a separate zone, and not to expand the room, then the foundation must be made separately and have an expansion joint

The base, made in the form of a solid slab, is difficult to rigidly connect to the existing base. The optimal solution is to make an expansion joint along the abutment line.

We are completing the foundation for a foam block building

To complete the construction of a building it is used various materials, including foam concrete blocks. They are distinguished by their low mass, cellular structure and do not require the construction of a heavy foundation. Let's look at how to properly make a foundation for an extension. Taking into account deviations in the mass of building materials, different shrinkage of buildings is likely. In this case, it is advisable to build a separate base and not strictly connect it to the existing base.

Algorithm for performing the work:

Mark the outline of the foundation being constructed using a cord and pegs. If the shape is complex, you can divide the contour into separate sections.
Check the diagonal difference. The absence of deviations indicates the correctness of the markings.
Dig a pit, ensuring a width of 0.3–0.4 m. Plan the base and ensure that the walls are vertical.

For a small extension, a pile-screw or shallow strip foundation is suitable

Place an even layer of crushed stone and sand on the base of the trench. Pack the pillow thoroughly.
Assemble the panel formwork. Check that there are no gaps through which the concrete mixture could leak.
Waterproof the formwork structure. Use sheet roofing felt, mineral wool or impregnating compounds.
Place the reinforcement cage into the formwork. Ensure that it is stationary and has a gap of 30–35 mm to the concrete surface.
Fill the structure with concrete mixture. Do not subject the hardening solution to deformation until final hardening.

When carrying out work, it is important to ensure a minimum gap with the existing structure.

We are constructing the foundation for a frame-type extension

The sequence of operations for building a foundation for adding to a wooden house is practically no different from constructing the base of the main structure.

Main stages:

Extracting soil to form a pit.
Assembling panel formwork for pouring mortar.
Knitting reinforcement mesh and fixing it in the formwork.
Filling the formwork with concrete mixture.

It is important to accurately connect the base being added to the base of the existing building. Despite the fact that the foundations were not erected simultaneously, they must be combined into a common power circuit.

Let's figure out how to properly make a foundation for an extension to a frame structure. Sequence of operations:

Extract the soil to the required depth to facilitate access to the base of the frame structure.
Dig a pit along the contour of the room being completed, keeping the two foundations equally deep.
Delete old ones waterproofing materials from the surface of the existing building base.
Make cavities to a depth of 60–80 mm for the reinforcing bars and drive them tightly into the channels.
Install the formwork structure from wooden shields along the perimeter of the future building.
Waterproof inner surface panels and seal possible concrete leakage areas.
Fill in concrete mixture into the formwork, thoroughly compact the solution using an internal vibrator.

After completing the work, wait for the hydration process to complete and the service strength to gain. Regularly moisten the concrete and cover the surface of the mass with polyethylene. By following this work methodology, you can combine buildings from different building materials.

Conclusion

Having decided to increase the usable area of a private house or country house building, it is worth considering all the points to avoid uneven shrinkage. It is important to decide on the sequence of work and study the technology. If you lack the skills, turn to professionals. They will carry out high-quality work and will not make mistakes.

Time passes, and it turns out that the private house no longer satisfies the owners with its size and amenities. A decision is made to expand its area with an extension. How to do this efficiently and without extra costs, we'll tell you in the article.

Save money without harming quality – requirements for premises and materials

Poorly thought out design of an extension will eventually force something to be redone or completed, or added to country house. In order to avoid getting into such a situation, we think through all the nuances, weigh the advantages and disadvantages of our idea. We start with choosing a location and size.

Each type of additional room has its own specific characteristics in connection with its use, requirements for insulation, waterproofing, and others. If a decision is made to build an additional living room at the dacha, then this is tantamount to the construction small house. It is necessary to reliably insulate and prevent the appearance of dampness. If you plan to stay in cold weather, you need to think about heating.

Another common type of extension is kitchens and bathrooms. The requirements for them are practically the same. First of all, we think about utilities and install them even before construction begins. It is much more convenient to lay sewer and water pipes before pouring the foundation than to dig underneath it later. Waterproofing requires increased attention flooring. We are thinking about insulation, but if the kitchen is planned for summer, then you can save on this.

The house is being expanded by adding a veranda. The structure is light, serves for summer recreation, protects the entrance from wind, snow and rain. It is carried out in many variants: from the simplest in the form of a boardwalk, low walls with a roof on pillars, to complex with walls, doors, windows. No insulation is required, otherwise it will no longer be a veranda, but waterproofing the foundation is necessary.

The extension to the house must be in harmony with the main structure. If the house has external decoration, then it will not be difficult to repeat it in the attached room. All materials go well with wood, which looks great even without additional finishing. The best option there will be a frame structure:

it is built quickly, literally in a few months;
does not require a capital foundation because it is lightweight;
without special knowledge and skills, it can be built with your own hands;
will cost less.

The foundation for the extension is made on the same level as the foundation of the house. When attaching a structure to a house, we do not do it tightly - over time it will shrink - but leave an expansion joint. In this regard, frame structures that do not shrink vertically compare favorably.

If the structure is attached to the front wall, the roof continues the main roof and is pitched. We choose the slope in such a way that the snow does not linger and the rain flows off. If this is an extension to a side wall, then the roof follows the configuration of the main one. The roofing material is the same as on the roof of the house, if different, it is important that they are combined.

Columnar base - fast, cheap, reliable

For the columnar foundation of an extension to a house, concrete, brick, or a combination of both are used. It is made mainly for a living room or veranda. If used for a kitchen or bathroom, thermal insulation of the utility lines entering the house will be required. Since the protection concerns an average of half a meter of pipes, such expenses can be incurred, and it will still be cheaper than a strip foundation. The floor is made of boards; for concrete, you will need a lot of backfill material and a fence around the perimeter.

We start by marking the area, the installation locations of the pillars are one and a half meters from each other. A separate hole of 50x50 cm is dug under each pillar, with a depth greater than freezing of the soil. At the top we expand the pits a little: about 10 cm on each side. We fill the bottom with a 10 cm layer of sand, compact it carefully, then crushed stone or broken brick, which is also rammed.

We lay out the film for waterproofing and bring the ends to the surface. If we plan to build brick pillars, pour a little concrete mortar into each hole for the base and wait for it to set. When planning concrete pillars, we tie reinforcement at the top along the entire height and lower them into the pits. We ensure equal distance between the walls. We place pieces of brick under the bottom to raise the reinforcement by about 4 cm.

We make formwork for the base, inside which we run the film. We pour the concrete in layers, pierce each layer several times with a rod to release air bubbles. It is important not to rush, it is better to wait until it sets, then continue pouring. We carefully level the top of the column and wait about two weeks until the concrete hardens. All this time, water heavily and cover with burlap or film.

When the foundation reaches the required strength, the formwork is removed. We heat up the bitumen mastic, apply it to the pillars and immediately glue pieces of roofing felt for waterproofing. There is space left between the pillars, which it is advisable to fill in to insulate the floor. We use ordinary soil mixed with crushed stone or pieces of brick. Fill in layers of 10 cm and tamp. The technology for constructing a strip foundation is practically no different, but unlike a columnar foundation, it is solid.

Getting started - bottom frame and extension floor

So, we stopped at frame version as the fastest and cheapest. In order for a tree to serve for a long time, you need to adhere to two rules: make reliable waterproofing and carry out antiseptic treatment. Of course, the wood must be well dried. For waterproofing the most reliable means– bitumen mastic. It is possible to use several layers of roofing material, but it is short-lived.

Then we do bottom trim. Usually 150x150 mm timber is used, but it is possible to use 150x50 mm boards. We lay them horizontally along the entire perimeter, aligned with the outer edges of the foundation. We do not connect the boards of the first row to each other. We lay the second row on top, overlapping the joints in the first.

In boards laid in this way on the foundation, we make through holes under the studs and connect them. If it is strip, we drill and connect it on the ground, and then lay it down. To get the effect of a single beam, we knock it down with nails in a checkerboard pattern every 20 cm. The result is a binding of the required thickness, which also has additional advantages:

costs much less than beams;
It’s very easy to connect with each other, but with bars it’s more difficult.

We attach the bottom frame to the beds from the same 150x50 mm boards, installed on top of the edge along the outer edge. We fasten them together and with the beds with 90 mm nails. Next we install logs made of similar material installed on the edge. The distance between them is 60–80 cm, but it all depends on the size of the frame extension: the longer the logs, the narrower we install them. They are attached to the trim board with nails, 2 on each side.

Now let's start insulating the floor. The cheapest, although not very environmentally friendly option, is tile polystyrene foam with a density of at least 15 kg/m3. Its advantage is that it is the only insulation material that is not afraid of moisture. We nail 50x50 mm bars to the lower edges of the logs, which will hold the polystyrene foam. A thickness of 15 cm is required: we use sheets of 10 and 5 cm. We lay them so that the seams of the bottom and top rows overlap.

The base is ready. We lay the subfloor on top. To prevent it from warping over time, we lay it alternating the direction of the annual rings. We look at the cut: we place one board with an arc up, the other - down. We make the finishing floor from plywood, the joints are staggered. A rough base is not necessary if there are edged tongue-and-groove boards with a thickness of 30 mm or more or 15 mm plywood. We lay it directly along the joists.

Wall installation - two assembly technologies

There are two assembly technologies frame buildings. The first is called frame-panel, when the entire assembly is carried out on the ground, then the finished structures are installed in place and fastened together. Sometimes the frame is immediately sheathed, which makes it even stronger. Another method involves gradual installation on site. Which one is more convenient - everyone decides for himself. A shield assembled on the ground cannot be lifted alone; assistants will be needed.

We begin the construction of the frame with the corner posts. For them and intermediate posts we use timber 150×150 mm or even 100×100 mm. The distance between the racks is determined by the width of the insulation, which we find out in advance. We position the pillars so that the gap between them is 3 cm narrower than the width of the insulation. This way we will save on waste-free use of material and improve the quality of insulation without leaving gaps.

Fastening can be carried out simply and reliably using metal corners installed on both sides of the racks and secured with stainless screws. Before finally fixing the stand, we carefully check its verticality, this is especially important for the corners. One incorrectly aligned beam will cause the entire extension to bend.

Support correct form the frame is helped by temporary bevels, which are installed from the inside and serve until attached external cladding. If the sheathing is made of a rigid and durable material such as plywood, OSB, GVK, it is capable of independently strengthening the base, which will stand securely after removing the temporary slopes. When soft material is planned for the cladding: siding, lining, then permanent braces cannot be avoided. It is better to install them two at the bottom and at the top of each rack.

At the places where windows and doors are installed, we attach crossbars. We make double racks next to them: they experience increased loads and must be stronger. The final fastening of the frame is carried out by installing the upper trim. In order not to invent anything, it can be similar to the bottom one: a bed made of two boards fastened together and the actual harness made of the same boards installed on the edge. To it, in the same way as the floor joists were attached, we nail the floor beams from 150x50 boards on the edge.

We constantly check the geometry of the entire structure, as well as the correct installation of the racks and crossbars: the racks are strictly vertical, the crossbars are horizontal.

Shed roof - design and technology

The roof of a house with an extension consists of two parts, which should be harmoniously combined into one. If the extension is built on the side, the roof will be a continuation of the main one; all that remains is to repeat its design in order to lengthen it. When an attached building is located along its length, its roof is made of a pitched roof. The slope is ensured by the difference in height of the front and rear pillars. The height of the rear ones should ensure that the roof of the extension goes under the main canopy.

The roof is supported by rafters, which we lay on beams. They are made from thick boards, to ensure fixation, we make special grooves. We cut them out on the ground according to a template so that they are all the same. Then after installation in place there will be no need to align horizontally. We treat the grooves with mastic, install them and fasten them to the walls with brackets and metal corners on studs. If the length exceeds 4 m, we install additional vertical supports.

We lay the sheathing on top of the rafters. Depending on the roofing material, we make it continuous or in increments of 0.3–0.6 m. The need for continuous wooden flooring arises in the case of soft material, we make sparse for all other types of roofing. We make fastening depending on the type of roof. We fasten corrugated sheets and metal tiles with special self-tapping screws having sealing washers, and ondulin with nails with a wide head. We provide wave overlap. Don't forget about the final design: wind strips not only protect the roof, but also give it a finished look.

Insulation is a mandatory operation for an extension

They are mainly used for insulation of buildings. mineral wool and polystyrene foam. Mineral wool resists fire and has low thermal conductivity. They are light in weight and have a consumer-friendly release form: rolls, mats. Another popular insulation material is polystyrene foam. Its advantages: it is inexpensive, not afraid of fungus, moisture, rotting. But there are two big drawbacks: rodents love it, and in case of fire it emits toxic gases.

We carry out insulation from the inside in the following sequence:

1. We install the waterproofing, having previously cut strips of the required sizes. We fasten with staples using a construction stapler, so as to ensure overlap. We sheathe the frame completely, driving in staples every 10 cm.
2. Place insulation between the studs. Ensure a tight fit to wooden structures, seams between separate elements We close the insulating material, overlapping the next layer.
3. We attach the vapor barrier, even if we use polystyrene foam. The fact is that it is necessary to protect not only the insulation, but also the wood. We perform fastening in the same way as waterproofing.
4. We cover the walls from the inside. We use plasterboard over a perfectly flat frame or OSB if there are any unevenness. It is tougher and smoothes out imperfections.

What remains is internal and external finishing, where there is room for the owner’s imagination. A frame extension is built quickly, cheaply, lasts for decades, and can be built with virtually no outside help.