Thermoblock house: construction technology

Recommendation points

• The foundation for thermoblocks
• Wall technology
• Wall reinforcement
• Reinforcement at corners
• Working with door and window openings
• Fill rules
• Overlapping
• Gables

Thermoblock is a versatile material that can greatly simplify construction procedures and build a house in a short time. Thermoblocks are presented in the form of two expanded polystyrene sheets, which are fastened together with connecting bridges made of the same material. Expanded polystyrene blocks are also called foam constructors, and their structure is made in such a way that, as a result, the wall will be an integral and strong element, since the blocks only play the role of formwork for concrete.

The standard size of one thermoblock is 1250x300x250 mm, and its cost ranges from $ 3-4, it is easy to calculate the average cost of one square meter of such a house.

Number of blocks per square 4 pcs. (minus 25%, since the block length is a quarter more than a meter):

• 3.53 = $ 10.5

One square uses 120 liters of concrete (the average cost of a cube of concrete is $ 160):

• 160 8 = $ 20

Total:

• 20 + 10.5 = $ 30.5

In addition, the thermoblock is an excellent insulation, the thickness of the expanded polystyrene plates on both sides is 50 mm, and thanks to special processing they also have refractory properties..

In order to visualize the savings in materials, we will calculate one square meter of a silicate brick house (also one of the common materials). The cost of one brick is on average $ 0.25, the quantity per meter is 60 pieces:

• 60.25 60 = $ 15

For a brick house to be as energy efficient as in the case of blocks, at least three rows must be laid out:

• 3 15 = $ 45

If you are not a good bricklayer, then you can safely add 50% from above for the work of a specialist:

• $ 45 + 50% = $ 67.5

The final savings are slightly more than doubled, and on large volumes of construction, this difference will greatly affect the financial situation..

The foundation for thermoblocks

In Russia, according to GOST, it is allowed to build buildings from thermoblocks no more than 9 floors high, but as practice shows, most often private houses with a height of no more than 2-3 floors are built from thermoblocks. For buildings of this size, it is customary to erect a tape-type foundation. The parameters of the foundation under the “thermal house” are calculated, first of all, based on the data on the depth of soil freezing in your region, on average, this value is 1200 mm, we add 20% to it and we get the height of the foundation. For standard private buildings use a foundation tape width of 500–600 mm. The weight of one square meter of the supporting structure of the thermal house is 350-400 kg / m², so for two floors such a foundation is quite enough.

If you decide to build a one-story house, then do not think that you can recalculate the parameters of the foundation and reduce its height, the height of the foundation cannot be set less than the depth of freezing of the soil, otherwise warm walls made of expanded polystyrene blocks will not help – the premises will always be damp and humid. In addition, it is required to take into account the additional weight of finishing and facing materials, and these are always unnecessary loads.

Wall technology

The hardest part is putting the first corners. To do this, you must make sure that the foundation surface is level. A standard building level is not enough here; you need to resort to the help of a professional tool – a level. If, as a result of sighting, it turns out that the plane has deviations greater than noma (when building a thermal house, the height difference of 10 mm at a distance of 8 meters can be neglected), then this “gap” can be easily eliminated. To do this, it is necessary to install the first blocks on the laid cement mortar, adjusting the level so that it is as horizontal as possible. The vertical level of the corners can be checked with a line level.

To continue the construction of the walls, it is necessary first of all to put the thermoblocks around the perimeter in two rows, docking them together. Docking of blocks is carried out according to the principle of building toy houses from a Lego constructor. Each block has grooves at the bottom to attach to the previous row, and similar tabs at the top to serve as a base for the next row of blocks. On the sides, the blocks are attached in the same way as tongue-and-groove boards – one longitudinal groove and one longitudinal ledge, which ensures the overall rigidity and immobility of the expanded polystyrene formwork.

If you decide to build a small house without a project and other documents, then you need to think in advance about the location of the internal walls of the building, since they must be installed and filled simultaneously with the contour walls, otherwise it will be very difficult to join them later..

When installing the blocks, it is necessary to use a dressing, each subsequent row should lie with an offset to the floor of the block. After installation, the blocks need to be additionally pulled together with jumpers, they are made of ordinary wire in the shape of the letter “P”, the height of the jumper should not exceed 50 mm, and the length within 150 mm. All seams, both horizontal and vertical, are pulled together by jumpers, this procedure is intended so that at the moment when the walls are poured with concrete, the integrity of the entire structure is not violated. The next day, these brackets can already be removed and used for the next blocks.

It is not always possible to calculate the project of the house in such a way that the length of the wall is a multiple of the length of the thermoblock without a remainder. Just like in brick houses, you will need to use halves or quarters of blocks. To do this, you just need to measure the desired length of the block and cut off the excess with an ordinary hand saw for wood. So if during the delivery or unloading of blocks, some of them turned out to be broken, do not rush to panic, you will need more such units than you think..

The only drawback during the construction of a thermal house may be that under the weight of concrete walls can “float”, especially in very long sections, as a result of which depressions and bulges can form. To avoid this problem, before pouring, you need to pull the threads on both sides of the wall, they will show you all the deviations, to eliminate them, you need to tamp the blocks with your palm in the required direction.

According to the technological process, it is allowed to fill in no more than 2–3 rows of walls in one day. This will allow the concrete to dry out and support the next potting layer. Such requirements are aimed at minimizing the likelihood of wall deformation during installation. If you still have irregularities, then you should not sound the alarm, the formed cavities will be eliminated during finishing work, for example, they can be plastered. You will have to work additionally with the bulges, it is necessary to outline the excess area with a pencil and comb the foam with a grout or emery to permissible norms.

Wall reinforcement

To ensure the rigidity of the walls, vertical and horizontal reinforcement is used. The concentration of reinforcing rods should not be higher or lower than the established rate. In the case of a lack of reinforcement, the walls may not be strong enough, and in the case of an excess, they may crack.

For vertical reinforcement, it is necessary to use meter sections of the 12th reinforcement. They can be inserted into already poured concrete without prior bonding. The vertical reinforcement step should be the floor of the block, two rods per cell. The sections are specially made of this size, since after pouring the next layer, the rods should stick out of the concrete by 30-40 cm, thanks to which the fresh layer of concrete will be able to firmly grasp the previous already dried layer.

Horizontal reinforcement is also called “reinforced belt”; it must be laid in three rows. The connecting elements of the thermoblock have special guides for this, into which the rods are laid. Before pouring, it is imperative to tie the contour of the belt together with a knitting wire and fix it with vertical reinforcement in the same way.

Reinforcement at corners

In order to organize a solid contour at the corners, it is necessary to make a corresponding hole in the thermoblock. For corner masonry, a thermoblock with one “blind” side is used, with this part it is mounted to the front side. There are no blocks with pre-drilled holes, so you have to do a little bit of knife work. This hole is cut from both the upper side and the lower, so that the concrete flows normally and forms a solid and strong knot.

Working with door and window openings

When erecting the upper part of the doorway, it is customary to use concrete lintels. For their manufacture, it is required to build a small wooden formwork according to previously thought out parameters. The length of the lintel should be greater than the width of the opening, at least 40 cm, if the opening width is standard and is 80 cm, then you can safely make a lintel according to the dimensions of the thermoblock.

The lintel is reinforced in two rows. Pour about 5 cm of concrete into the formwork, then lay two longitudinal rods and on top of them transverse ones in 20 cm increments, then pour concrete until a level of about 5-7 cm remains, repeat the procedure with reinforcement and fill everything to the end. Before smoothing the fresh concrete surface, it is necessary to release the maximum possible amount of air from the product, tap the formwork in a circle with a hammer for one or two minutes.

To prevent the concrete product from grabbing onto the bottom surface, at the time of manufacture, put a layer of oilcloth under the wooden formwork. The jumper should dry for at least 3-5 days, so it’s best to make everything in advance.

In the case of window openings, the situation is much easier, the upper part of the opening is built up with thermoblocks like an ordinary wall, with the only difference that a board is placed under the base of the block, which is designed to play the role of formwork in order to hold back the concrete. The board should be solid along the length of the entire opening, from below it is propped up by vertical wooden posts – this method ensures the reliability of the structure. Further, the wall is simply poured, and the board, for greater reliability, can not be dismantled until the end of the construction of all walls.

Fill rules

It is necessary to fill it using certain methods, otherwise the result may not be quite expected. The first thing to remember is that it is not recommended to automate this process. Do not use imported concrete and gasoline pumps, it is best to fill the walls with a bucket, making a solution in a concrete mixer. Thus, you will not break the even structure of the walls, and the finished solution will not dry out while waiting for you to use it up, since each next square will be filled with a freshly prepared portion.

The upper row of blocks is poured only to half the level of the block, and the concrete surface, before being left to dry overnight, does not need to be smoothed with a trowel, even if it is better slightly embossed, this will ensure better adhesion of the two layers to each other.

Overlapping

Most often, ready-made concrete slabs are used to organize the overlap between floors. Some people prefer to make them on their own on site, but this is a rather time-consuming process, it is better to order a finished product, which will be delivered by a truck crane to your facility and installed using it..

The slabs must be ordered in such a length that, as a result of the installation on the sides, about 2-5 cm of the concrete base of the walls remains, this will allow us to connect the walls of the two floors into a single whole with concrete mortar, thus creating an integral structure.

Before installing the floor slabs, the wall must dry out very well, for this you need to wait at least 20 days. The last row of the wall must be poured with a reinforced belt, regardless of the standard horizontal reinforcement pitch.

After installing the slabs, you can start masking the end parts of the floors. To do this, it is necessary to cut the thermoblocks so that only the side sheets remain. At the ends of the floors, we build an impromptu formwork from these boards and fill it with concrete.

Gables

After the floors are built, you can start building the attic space. The basis for the rafter is the pediments – vertical triangular walls. Regardless of the number of roof slopes, the gables are made using the same technology.

The technology for erecting gables does not differ significantly from erecting walls, the only difference is that the extreme blocks of gables must be cut with a hacksaw at a certain angle, this will ensure an even level of the hips of the triangle. There is a simple way to make sure that the concrete solution does not flow out from the sides of the pediment, but takes the correct shape, for this we cut out the plates of the appropriate size from the foam sheets and fasten them in the form of covers on the side, fastening them to the main blocks with the same jumpers in the form of the letter ” P “made of wire. One day after pouring, they can already be removed to allow the concrete to dry completely. After all the concrete elements of the building are completely dry (from 2 weeks to a month, depending on the ambient temperature), you can proceed with the installation of the rafter, the outer facing layer and interior finishing work.

The exclusivity of this technology lies in the fact that almost everyone can build a similar house on their own, without the involvement of specialists. You don’t need to be a professional to work with thermoblocks, you just need to be able to use a standard set of construction tools. The structure of the block will not allow you to spoil the level of masonry, guided by the recommendations of this article, you can build everything that you need, the main thing is to have the desire and diligence.