- The main problems of individual housing construction
- The other side of the coin
- Is frame construction technology flawed by itself??
- Components of a good frame house
- House foundation
- Walls and insulation
- Overlapping and layout
- Roof and attic
- Other features
Over the past decade, an ambiguous situation has developed on the private real estate market. On the one hand, there are many lucrative offers for the sale of country houses at an affordable cost, on the other hand, the quality of such housing, to put it mildly, leaves much to be desired.
Frankly speaking, the average Russian resident cannot afford a really nice house designed for permanent comfortable living. There are a number of reasons for this, some of which lie in the purely technical aspects of construction, while the other concerns the lack of funding and the dominance of unscrupulous contractors among the construction teams..
The main problems of individual housing construction
What construction companies do really well is advertising: neat country houses with elegant finishes look impressive against the backdrop of a beautiful landscape. The price tag is also nice: from 10 thousand rubles. per m2, that is, a small family may well keep within 700-800 thousand rubles. The declared construction time is from one summer season to a year. Isn’t it a great offer?
We are talking mainly about houses built using frame technology. Only this type of design can claim high efficiency with a short implementation time. However, when asked to comment on such trade offers, construction specialists only shrug their shoulders: at current prices for materials, it is impossible to build a frame house for that kind of money, even in austerity. Moreover, it is impossible to build a turnkey building, designed to operate for at least 30 years, so that at the same time its heating does not eat up the lion’s share of family income.
But how do such houses come into being? Most developers work on the pyramid principle, simultaneously processing 3-5 construction phases. With money from customers of the first stage, foundations are laid, which are left until the soil shrinks. Conducting vigorous activity allows attracting the next stages, on the funds of which the objects of the previous ones are completed, and when the infusions become insufficient to continue the work, the enterprise is liquidated. Even if a court decision is subsequently made against the developer obliging him to return the invested funds, recovering money from bankruptcy will take decades.
The other side of the coin
For the sake of fairness, it is necessary to clarify that construction companies that offer really high-quality frame houses exist in Russia, but the price tag in their catalogs starts from 4-5 million rubles per project without the cost of the land plot. For a person with an average income, this is an unaffordable amount. The mortgage does not solve the situation, because for its registration a number of examinations are required, confirming the safety and final operational characteristics of the building, which allow insuring the pledged object on the terms of the bank. In the best case, the buyer can count on a bank loan at 10-15% per annum, but its size does not cover even a third of the cost of building a house.
The main problem is that building and sanitary requirements are not mandatory when building houses in private. Developers willingly take advantage of this, saving on materials, adherence to technology and qualifications of the employees involved. As a result, the house does not even comply with the basic thermal protection standards, which are far from desirable in themselves, and the real life is no more than 20 years.
It will not be possible to hold the developer accountable, despite claims of warranty and quality control. Every 2-3 years the list of the main contractors in the region is updated, the liquidated companies enter the markets under new names. In addition, the scammers have a solid legal basis and extensive experience in such cases. Streamlined wording in contracts and the absolute absence of signatures of competent specialists under the design documentation make it impossible to find the culprit who will compensate for the damage.
Is frame construction technology flawed by itself??
There is one more, very unobvious problem of IZhS on wireframe technology. Their PR was carried out on the basis of real examples from countries of near and far abroad with an equally harsh climate. It was declared that if in Canada or, say, Finland, frame houses serve regularly and remain warm for decades, then the domestic consumer deserves the same.
In reality, houses that are being built in Russia have nothing to do with either Finnish or Canadian ones. The first evidence of this is the price, which is about 300 thousand euros for a set of Finnish house of 90 m2. The second is that such materials as high-quality LVL, reinforced gypsum board, industrial grade Scano boards, anodized brushed nails and a vapor barrier LDPE film with a density of 400 g / m2 are unavailable on the domestic market.2. The list goes on and on.
In reality, the average frame house costs 5 million rubles. – a rather flimsy structure with basic thermal protection, which loses up to 50% of its initial values within 5-7 years due to mineral wool shrinkage. The use of wood of natural moisture content (more than 20%) leads to warping and cracking of the finish, divergence of the siding joints and weathering of the wall filler, loss of strength and bearing capacity. There are dozens of other problematic issues with regards to the foundation, floor insulation, floor stability, insulation of openings, etc..
This does not mean at all that it is impossible to build a good and durable frame house in the CIS. If the construction is carried out with your own hands, it is enough to make informed decisions, using the recommendations of trusted specialists. If the work is carried out through a construction contractor, you need to contact only those companies whose advertising is a public offer and demand to rewrite the contract with an indication of the work schedule, schedule, deadlines, and most importantly – clear final characteristics of the construction with reference to the current SNiP and SanPiN. The presence of a construction project certified by an accredited architect is also strictly required.
Components of a good frame house
The best way to build a good frame house is to know the nuances in which contractors allow connivance or negligence, and independent builders make mistakes out of ignorance. Yes, compliance with all the requirements of the technology increases the construction budget, but this overpayment cannot be compared with the subsequent expenses for heating, periodic repairs of finishes, and replacement of insulation. The more expensive a frame house is to build, the cheaper it is to maintain.
Builders are often deceived by the relatively low weight of the enclosing structures and floors, believing that even a pile-screw foundation can hold such a house. At the same time, complete disregard for the dynamic load and the forces of frost heaving is demonstrated, no one conducts geological surveys either..
The frame structure is indeed lighter, but less stable. Deformation of the foundation is not accompanied by the destruction of the wall, as is the case with brickwork, however, an increase in the eccentricity of the loads inevitably leads to the appearance of unsteadiness and an even stronger propagation of vibrations. A frame house can only be placed on a concrete foundation, the best option for which is a monolithic insulated slab or MZLF in regions with a temperate climate. In the case of construction on peat bogs and other weakened soils, a pile-grillage structure should be laid.
Walls and insulation
Good thermal insulation of a frame house can be achieved only if the thickness of the insulation is 200 mm and there is a thermal break in the supporting system. Since a composite beam in the realities of a domestic construction site is an unaffordable luxury, the Canadian construction scheme is considered optimal, according to which a two-row frame is arranged from offset racks 50×100 mm. Only kiln-dried sawn timber with fire-retardant impregnation is suitable for the construction of a frame house; any fasteners must have an anti-corrosion coating.
Mineral wool fits only into cells formed by horizontal bridges of thin plywood. The permissible cell height depends on the density of the cotton wool and is on average 80–100 cm. During the period from unpacking and laying the mineral wool and up to the installation of external and internal wind and vapor barrier, dry and clear weather should remain. Even the slightest ingress of moisture into the insulation irreversibly changes its properties.
Overlapping and layout
In frame houses, overlapping is one of the most problematic places. It is very difficult to ensure rigidity and good sound insulation between floors, especially with a beam thickness of 150 mm, which is considered the standard for domestic facilities. The frame slab must have sufficient deflection resistance to be cast with a semi-dry or standard screed..
Since the purchase of large-format sawn timber in most regions is a big problem, it is recommended to choose trusses assembled on studded plates with a height of 300 mm or more with plane-parallel belts and half-slanting filling as the load-bearing elements of the floor. In some cases, a wooden I-beam can be considered as an alternative. A prerequisite for overlapping is a double-sided vapor barrier and a cement screed from 30 mm on a rough flooring made of isoplate 25 mm thick.
Partitions in a frame house are usually planned in advance, which allows for the placement of additional support points for the floor. In some cases, it is possible to give preference to a building with a free layout, if there are good reasons for that, and the floors and roofs were designed taking into account the partial loss of the bearing capacity by the walls over time. As a rule, the same wooden frame acts as the base of the partitions, but this is not necessary. It is possible to use cellular gypsum partitions, gypsum board on a galvanized metal frame and even porous ceramics. The main requirement is to provide high-quality sound insulation, for which the partitions separating living quarters and cutting off technical areas must be double-row with mandatory filling with mineral wool.
Roof and attic
For frame houses, roofs are recommended that are designed for the independent descent of the snow mass, that is, with an average and steep slope. Lightweight roofing materials are best suited: bituminous and metal tiles, folded iron, composite slate. The roof is supported by a classic truss system with struts, the attic floor beams play the role of braces. Mauerlat in a frame house is not mounted, so a sufficiently large thermal bridge is excluded. Instead, the rafters are attached to the floor beams using studs or studded plates..
The most problematic place in the thermal insulation of a frame house is insulation under the roof and in the plane of the attic floor. If the attic is cold, at least 300 mm of mineral wool with a density of 60 kg / m and more are laid in the ceiling3. In this case, there is either no upper flooring at all, or sheet material, laid without fastening, plays its role. In a warm attic or attic arrangement, at least 200 mm of cotton wool with a density of 30-35 kg / m is laid under the roof3. From the inside, a hinged sheathing with a box is necessarily mounted. The most important thing in the upper zone of insulation is reliable protection against moisture, the best option of which is a dense polyethylene film with soldered joints.
One of the most important nuances of the construction of a frame house is the control of the internal climate. Gas exchange with the external environment is completely excluded, therefore, a residential building must be equipped with supply and exhaust ventilation. In order to save money, it is recommended to install a system with an adjustable capacity and a recuperator, or to organize a warm attic.
The second point is the isolation of abutments in openings. The frame technology is designed to form a continuous thermal protection loop, in which windows and doors are the natural and largest bridges of cold. The presence of a thermal gap between the frame and the main structure can reduce the residual heat loss by half.
In conclusion, a few words about facade finishing. For more reliable protection of the insulation against wetting and reduction of heat losses, it is recommended to use a hinged ventilated facade system with limited ventilation of the cavity under the cladding. In addition, this finish has the highest service life and is well suited to deformations of the supporting frame..