We build our wooden houses mostly from laminated wood. Laminated wood is wood that has been cut into long boards, then glued again to form one massive log. It may sound a little strange to first cut wood into pieces and then glue it back again, but this cutting and glueing has distinct advantages.
Wood dries over time. Immediately after cutting wood has a moisture content of 50%, and within a few months by the roadside the moisture content has already dropped to 30%. But before we can use the wood in house construction, the moisture content should be lower than 20%. And when the house is finished, over time the moisture content will drop to somewhere between 5% and 15%, depending on ambient temperatures and relative humidity of the surrounding air.
And with the drying comes the cracking. A little crack here and there may not be a problem, but big cracks are not good for the insulation properties.
And there is little you can do about it. Except laminate: laminating results in wood with minimal to no cracks. More info here. So that is reason no. 1 why we use laminated wood.
Standard massive wood can have a moisture content from 20% to 30% at assembly time, and the drying not only makes the wood crack, it also makes the wood shrink. And shrinking can give you a few headaches.
Here we go: the height of your house goes down from say 6.00 meters to 5,50 meters. Yes, massive non-dried wood can shrink that much! No problem, you say? So what about the doors and windows? They don’t shrink, so how will they still fit in the walls? And what about the raingutter downpour pipes? They get pushed into the ground, or they rip of the roof. Vertical copper pipes inside your house for hot or cold water, what do you think will happen where they connect to the sink or the crane?
Laminated wood is much drier (below 18% moisture content) when we use it to assemble our houses. It still shrinks about 1% in size, but we can easily deal with 1%, we have standard solution for that.
Stronger, Longer Spans
Massive beams come in standard dimensions, with a maximum length of about 6 meters and diameters of up to 30 centimeters. You need something longer, or thicker? Well ehh… sure you can buy it, but it will cost a fortune. I car terms: more like an Aston Martin or a Bentley. But our houses are more like Volvo.
Laminated wood you can produce in any length or diameter. And that is what we do. Thanks to laminated wood, we can have overlay ceilings that span 12 meters instead of 6 meters, without a column in the middle. And that is: 12 meters in Norway, with a substantial snowload. Serious stuff.
Actually we could go further. With laminated wood you can easily build bridges that carry 30 tonne trucks. But we still need to transport our logs, so 13 meters is about the maximum length that we use or they will not fit in a truck.
How To Laminate
So how do we laminate? We could try to explain, but it is far easier to take a look at this Youtube movie.