Adding the insulation on the outside has started. We are lucky with the weather, no rain at all. Having rain while doing the insulation works is not impossible and the insulation will dry without any problem, but it is easier to install it in dry conditions.
Anybody that is in the process of designing and building a new house runs into this discussion: should we build with a damp-open construction, with damp-open walls and roof, or not? Because opinions differ, and the debate is heated, amoung architects and building engineers. One is more energy-efficient, but the other is more ecological… etcetera…
What is this all about? And what is better?
This post is about wooden houses from Russia. Traditional wooden houses from Russia are a little different from the houses that we build, both from a design point of view as well as technically.
The design and style of the traditional Russian wooden houses obviously is different from what we are used to in West Europe. Generally speaking the materials are a little rougher, while at the same time there is a lot of fine hand-crafted woodwork in the details.
Technically these houses often have little in the way of a foundation. Many are built on permafrost terrain where it is difficult to dig a hole and build a foundation, so the house is built on top of the permafrost. Then once the house is built, the heating makes the permafrost a little less perma, and the house starts moving.
Many of them are built using round logs for which you will have a problem getting a building permit here, unless you are high-up in the Alps and also they use non-dried non-laminated wood. Non-dried non-laminated wood shrinks and cracks, but otherwise it is not that bad, and it certainly has a lot of charm. It’s a matter of preference.
There is no additional insulation on the outside or the inside. Even with the excellent insulation properties of wood (compared to brick or concrete), these houses will never meet today’s West European insulation requirements. Walls have Rc-values around 1.5, no higher than 2, compared to our walls having anything between 6 and 10, and these houses are not airtight: there will be drought in every corner and around every door and window.
With the low cost of energy in the outback (plenty wood) such Rc-values are not really an issue. Mind you, until recently these Rc-values were quite the norm in Europe as well. Also a little drought works like ventilation which is always good against condensation.
The photo on top was taken by Maxim Shemetov, a Russian photographer from Moscow. Maxim’s work with more images of traditional Russian wooden houses can be found here:
The general idea about wooden houses is that they are very well insulated, and a lot better insulated than brick houses. Is this correct? A short explanation.
We build two types of wooden houses: traditional log houses, and panel houses. Both have pros and cons, today we want to discuss the traditional log house.
How We Build Energy Efficient Log House
First we build a wall from solid laminated logs, 80-200 millimeter thick, then we add insulation on the outside and finally we cover the outside with decoration planks, usually from larch. The building process is as follows:
- first logs
- then insulation
- finally a larch cladding on the outside
Why is this an excellent construction method? Continue reading
Previously we wrote about a house that we built in Belgium. This house had double outside log walls (2 x 8 centimeter massive wood) with 20 centimeters cellullose between the walls.
The advantage of this construction was the damp-open construction (no plastic foils anywhere in the walls) plus the enormous thermal capacity of the walls. In the evening the walls warm the house, during summer daytime they cool the house.
And there is yet another advantage of cellulose: the fire rating. If impregnated with fire retardant material, cellulose will not burn. Look at the video below where different insulation materials are compared. It is not a scientific test, but it gives a good impression of what happens in case of fire.
We try to avoid polyethylenes and polystyrenes, whether extruded or expanded, as much as we can. It has zero thermal mass, it burns and often with a lot of black smoke, it turns into chemical waste.
Instead we use Rockwool, cellulose, sometimes wood fibre (not tested in the video above). But the poly-stuff we avoid.
Some people want to build a house just from a single log (no additional insulation on the exterior). In such case between the logs we use a thin strip to stop any draft.
In Belgium we just finished a traditional double wall log house. Traditional as in: traditional looks, and traditional techniques. We used as the insulation material between the log walls, instead of the more common rock wool or glass wool.
The advantage of is that it absorbs humidity, and can act as a buffer for humidity, just like wood. It breathes, just like wood, and it stores humidity, just like wood. It creates an enormous thermal mass.