Adaptation of the construction of a frame house to Russia: which causes quality problems

Recommendation points

• Element No. 1. Lumber
• Wood moisture
• Wood storage
• Element No. 2. OSB
• Element number 3. Antiseptic
• Element No. 4. Vapor barrier and ventilation

The article describes the main points of the “adapted” construction of a wooden frame house, in which the original technology is violated, modified or completely excluded from the workflow. We will tell you what the correct Canadian technology looks like and give examples..

It is not without reason that the name of the frame construction technology mentions the binding to a specific country. This carries information about the region of operation for which the house is adapted. “Canadian technology” in Russia means an approximate principle of the formation of walls and ceilings, structurally repeating the overseas prototype. We will analyze step by step each element of the frame and find out what violations are usually allowed when creating them.

Element No. 1. Lumber

A tree is a living organism created by nature itself. The properties of one breed will differ from country to country due to climate and air composition. But this is not the main problem. It so happened that our Western colleagues have a tradition – to closely research the already implemented technologies in order to improve them. This mentality trait made it possible to derive optimal formulas for the harvesting and use of lumber, which brought the technology literally to perfection..

Wood moisture

In the original technology, there is no concept of “humidity up to or more%” or “15–20%”. There is always a specific figure ± 1%. Moreover, this figure will be different for different regions. In all cases, regardless of the location of the construction site, a chamber drying is negotiated, which allows you to control humidity with an accuracy of 1%. The conditions for the transportation and storage of lumber are specially discussed. It also takes into account the time that the board has to sit on the construction site – usually 8-12 hours – before it can be applied (adaptation to the humidity of the place).

Wood storage

This stage is the longest for a board that is in a free state. Depending on the time of year, Canadian or American builders erect various temporary structures for storage of timber. It can be simple sheds in summer, moisture-insulated warehouses in spring and autumn, or insulated warehouses with heating in winter. Of course, the creation of additional utility rooms entails additional costs. It all depends on the urgency. It should be noted that 90% of the frame “boxes” are erected in summer in dry and warm weather. Year-round construction of wooden houses using frame technology in any weather is not considered the norm.

General conclusion on wood moisture content: it must be consistent with the humidity of the area in which the building is being built. When storing material, moisture balance and storage method must be taken into account.

Element No. 2. OSB

We will not consider cases of direct violation of technology – the use of plywood, boards or chipboard instead of OSB, or the use of this board indoors. Let us dwell on one point: in Russia, 3 types of OSB can be purchased in mass sale and they differ in density and size of chips. Overseas stores offer at least 7 types of this plate. It would seem, why so much? Additional 4 types differ in vapor permeability and moisture resistance. This is a tribute to the need to please all construction regions. According to needs, local factories produce mostly a specific brand.

General conclusion on OSB: in the Eurasian region, the limited capacity of local factories does not allow full compliance with the original technology.

Element number 3. Antiseptic

Antiseptic coating with a brush or roller gives the moral right to consider the board protected. Especially if pigment is added to the antiseptic. Even if we close our eyes to the quality of application, the penetration of the substance into the wood with this method is measured in a few microns.

“Self-respecting” wood suppliers in the EU and at home technologies almost always have autoclaves at sawmills for impregnating boards with an antiseptic. The liquid composition is injected under pressure and temperature, 100% impregnating elements with a section up to 120×120 mm. The material with a larger cross-section is impregnated to the core. Then the board (or timber) is dried naturally and in chambers. Of course, this is not a “law” – any wood may be required, including freshly sawn.

General conclusion on antiseptic treatment: autoclave impregnation is the only truly reliable way to protect lumber from harmful factors using an antiseptic. It is also the most efficient way to implement its properties. The rest of the methods are nothing more than complacency.

Element No. 4. Vapor barrier and ventilation

Despite the absolute environmental friendliness of the tree, frame ladies are “thermoses”. The proposal to build a house with “breathing walls” is a marketing move, since the technology does not provide for vapor permeability of the walls. Any original manual for assembling a frame (or SIP) house provides for a vapor barrier – polyethylene or an analogue – with which all rooms are sheathed from the inside.

Finland. Construction of a frame house in the video – vapor barrier

But with this arrangement of the wall cake, condensation from steam and moisture should simply soak the interior decoration. How is moisture removed? The answer is simple – forced supply and exhaust ventilation. The simplicity of the answer is due to its complexity and high cost. In homes in the homeland of technology, ventilation with design, installations, materials and work is up to 30% of the total cost of the house.

Be careful! Developers who offer to quickly and cheaply assemble a frame “box” never highlight this point. Exhortations that micro-ventilation through windows will be enough is fiction (especially in winter).

To put an end to the conversation about “breathing walls”, let’s turn to the background information:

1. Vapor permeability of mineral wool (wall plate) – 0.49 mg / (m h Pa).
2. Ecowool vapor permeability – 0.32 mg / (m h Pa).
3. Vapor permeability OSB-3 – 0.12 mg / (m h Pa).

A simple comparison leads to the conclusion that OSB will not let the wall “breathe” fully. But to remove heat and moisture that this plate will pass through, a superdiffusion membrane must be used. In our stores, we can purchase 3-5 types of this barrier, which will differ in price and manufacturer. Compliance with the technology obliges to vary the membrane throughput depending on the following indicators:

1. Wall cake composition.
2. The thickness of the layers of the cake (from heat engineering calculation).
3. Insulation material (mineral wool or ecowool).
4. Indicators of temperature and humidity of the construction region.

In total, the range of Western manufacturers includes up to 40 types of membranes, used in different cases and combinations.

General conclusion on vapor barriers and ventilation: a frame house built in compliance with the technology – a thermos that needs forced ventilation. The outer membrane requires an independent crate, and the inner vapor barrier (polyethylene) can be stuffed directly onto the racks.

All of these operations increase the construction time and cost of the work. Especially preparatory and research. Considering that Canadian technology has been massively used relatively recently – for the last 15 years, even on the first houses “well-built” using adapted technology, the really serious problems discussed in this article have not yet appeared.

Unfortunately, future owners of a budget frame house often simply have nothing to compare it with, and a house that looks like new always evokes a storm of positive emotions, forcing them to neglect caution and logic..