Myths and reality of panel-frame housing construction

Recommendation points

• Panel-frame housing construction: Canadian technologies in a Russian way
• Flammability
• Sustainability
• Pros of a Canadian house built according to all the rules

Panel-frame houses have been in great demand lately. The highly publicized SIP technology promises practicality, cost-effectiveness and high-speed building construction. Are sandwich panels really that good, we will tell in our article.

SIP-technology is a fairly young type of construction, actively used over the past fifty years. In Russia, such houses are most often called “Canadian”, since the domestic code of rules SP 31-105-2002 “Design and construction of energy-efficient single-family residential buildings with a wooden frame” was based on the Canadian prototype.

Panel-frame technology has been studied up and down, but, alas, not in our country. And if Western experts thoroughly tested all the nuances of SIP construction, in Russia, unfortunately, such studies have never been carried out. Ignorance in this matter has given rise to many myths about both the dangers and the benefits of Canadian houses..

Panel-frame housing construction: Canadian technologies in a Russian way

The panels of the frame house are made according to the sandwich principle: plate-heater-plate. Classic – the use of oriented strand board OSB-3 and expanded polystyrene with a brand of at least 25.

However, Russian realities require a reduction in the cost of production, so unscrupulous developers tend to save on everything: OSB-3 is replaced with a less dense plate or analogues (cement-bonded chipboard, glass-magnesium sheet, FSF plywood), expanded polystyrene – with cheaper foam or mineral wool insulation, save on protective props and neglect the rules of interior decoration.

The result is obvious: a bad reputation has been fixed for panel-frame houses. Opponents focus on 2 main disadvantages of SIP technology – high flammability and low environmental friendliness. Let’s consider each of them in more detail.

Flammability

The use of phenolic resins and combustible polystyrene is the main argument for the fire hazard of “Canadian” houses. However, according to fire statistics, fire occurs in 90% of cases due to violations of safety measures inside the premises. Non-combustible walls and ceilings are of fundamental importance only in multi-storey construction, where smoke can cut off the path to the escape route. In private houses, evacuation occurs much earlier than the ignition of the walls..

Let’s compare the indicators of “flawless” wood and “dangerous” SIP-panels:

	Wooden structure	SIP panel without finishing
Fire resistance	K3	K3
Permitted applications	Single-family and block houses	Single-family and block houses
Fire toxicity	Gives off about 350 toxic substances and carbon monoxide	Insulation expanded polystyrene releases a toxic substance styrene, high concentrations of which cause nausea and irritate the eyes
Combustion protection	Flame retardant impregnation	Internal lining with plasterboard

The biggest problem of panel-frame houses is the use of low-quality materials for the manufacture of SIP panels. Expanded polystyrene, produced in compliance with all technological conditions, contains only 2% of a combustible substance, the rest is air. If the technology is violated, the slab “dries up”, as a result of which not only the thermal insulation properties deteriorate, but also the proportion of the toxic component increases.

However, when you approach life-threatening situations (for example, the infamous Lame Horse fire) from the perspective of a professional firefighter, interesting details emerge. In the overwhelming majority of tragedies occur not because of the special flammability of building materials, but because of the violation of technical regulations during construction and the absence of emergency exits.

Sustainability

The ecological background in “Canadian” houses is determined mainly by the cladding made of OSB-3 panels. For many years, heated debates have not subsided around them: opponents compare the composition with chipboard plates, supporters cite Western countries as an example (Germany consumes about 16% of the total amount of OSB-3 produced).

Unlike foam, there are no counterfeit OSB-3 boards on the Russian market – their production is too expensive. Almost all products are imported. The pitfalls are not hidden as a slab, but in its classification by the level of formaldehyde content:

• E1 – up to 0.1 ppm
• E2 – 0.1-1.0 ppm
• Е3 – 1.0-2.3 ppm

These are data from European standards, in Russia the figures are slightly higher, but remain within the normal range. For the manufacture of sandwich panels, according to the rules, a board of class E1 must be used, the formaldehyde content of which is practically the same as in pure wood. Products of this level are produced by the German concern EGGER. It is easy to guess that the prices for high-quality slabs are quite high..

The eternal desire to save money leads to the use of cheaper analogs – class E3 instead of E1, thickness 9.5 mm instead of the declared 12.5 mm.

In addition, in the same Germany, panel-frame houses are sheathed from the inside with a double layer of drywall, and from the outside they are finished according to the principle of a “wet facade” (foam + mesh + layer of plaster).

Pros of a Canadian house built according to all the rules

In Russia, “Canadian” housing construction is positioned as one of the cheapest and fastest types of construction. And if the speed and simplicity of the construction of such structures is beyond doubt, then the cheapness, as we found out, arises solely from saving on the quality of materials and neglecting the rules of interior decoration.

Advantages of panel-frame housing construction	Norm	Violation of standards
Unique thermal protection	Expanded polystyrene brand P25	The use of mineral wool or low-quality foam plastic reduces the heat protection indicators by 1.5 times
Energy saving	Lack of cold bridges when using dense insulation and double skin	Decrease in thermal insulation properties due to shrinkage and moisture of mineral wool.
Saving on the foundation	Pile foundation	Arrangement of less labor-intensive types of foundations
No shrinkage and warping	When following technology	Defects of poor quality assembly

Building a house is a long, troublesome and very costly business. Each technology has a lot of pros and cons that should be carefully studied before starting construction. Choosing SIP technology, you should make sure in advance in order to bypass all the pitfalls:

1. Choose sandwich panels from a factory manufacturer. Their origin must be confirmed by documents and certificates.
2. It is better to give preference to the proven classics – a combination of OSB-3 and expanded polystyrene. Innovative technologies do not yet have a meaningful lifespan.
3. Check the quality of the materials used in the production – the class of panels and the brand of expanded polystyrene. Large factories mark the OSB board at the end, indicating the thickness and class.
4. Ask the builders for recommendations, ideally visit several built houses and chat with the owners.
5. Don’t skimp on skilled assemblers. Elimination of flaws and defects in the finished house will result in a lump sum.
6. Pay special attention to the interior and exterior of your home. Use only quality materials and resist the temptation to disrupt technology.

Remember the good Russian proverb – the miser pays twice. This rule works in a hundred percent of cases: the cheapness of handicraft technologies directly affects the quality and comfort of your home. Successful construction!