Previously we wrote about types of wood (wet, dried, laminated) and the shrinking of log houses and how we deal with the shrinking. In this post we want to show a little more about the actual drying process, and cracks. Because drying and cracks are very much related.
Why Does Wood Crack?
The photo below shows a crack in a wooden disc. Why does wood crack like this? Very simple: drying.
cracked wooden disc
When wood dries, the drying process starts at the outside of the logs. While the humidity goes down from 15% to 12% near the outside of the log, more to the the center of the log the humidity initially remains at 15%. And that is a problem.
Oosterwold is an area just East of Almere, 30 kilometers from Amsterdam. Over the next ten years the municipality expects some 15,000 houses will be built in Oosterwold.
Is this interesting news for English-speaking readers? Maybe not. Most likely you are in the UK or Ireland, maybe you’re looking to build a house in France or Spain, and very few English or Scots actually want to re-locate to The Netherlands because of the nice climate, the beautiful cows or the cheese.
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. Want to know the winner without going through the whole video? Skip to 14m:30s.
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.
As we built custom design houses every project is unique and exceptional. We have built contemporary log houses and with this client we got a chance to compliment our list with a beautiful mountain chalet, designed by architect Stéphane CICUTTO GUIFFAUT from Chamonix Mt. Blanc (contact details at the bottom of this post).
We have delivered a truck with a wooden house to a client in Gastes, near Bordeaux in France. This client wanted to build the house himself. It is not what we normally advise, but on the other hand: it’s not rocket science, and with sufficient experience it is possible. Our kits come with good documentation.
For a few days after delivering the house we heard nothing. Silence. And then: a first photo, after a few weeks one more. This client has figured it out Bravo! Check floor plan. Continue reading →
Nowadays many houses are being equipped with solar panels. They generate energy “for free”. Maybe not entirely for free because you need to buy, install, maintain and depreciate them, but once you get them working you have less worries about the electricity bill.
There are two problems with solar panels: they look ugly, and they produce electricity when you don’t need it.