Holz100 Is A Cross Laminated Timber Held Together With Dowels

Touring the exhibits at the Wood Solutions Fair, I saw this: a block of wood held together with dowels. I called out “Brettstapel!”, the name of a clever method of building with wood that we have covered in TreeHugger, where the wood is held together with very dry dowels; when they absorb moisture from the surrounding wood they expand and lock the assembly together. (It is also now called DLT or Dowel Laminated Timber.)

In fact, the people in the Holz100 Canada booth were showing a different product, Holz100, invented and patented in 1998 by treehugging engineer Dr. Edwin Thoma. Brettstapel is made by stacking wood planks. This is much more like cross-laminated timber with dowels instead of glue:

I believe that dowel laminated timber is one of the most interesting ideas in wood, primarily because it is just that, solid wood with no chemicals, no glues. The Thoma design as a few additional benefits; being a CLT it is probably stronger and more stable. It uses a lot of wood but Holz100 is made from totally sustainable sources. There are other pluses, including energy efficiency, a healthy, biophilic environment:

Building with solid wood also controls humidity naturally. “There is no necessity for vapour barriers. The wood breathes by itself and naturally controls the indoor climate. The air tightness ensures no unnecessary heat loss.” Such thick wood walls also provide great soundproofing.

It’s all cut to order in the factory with efficient tools:

I am skeptical about some of the claims made for the product, such as “Holz100 almost entirely shields against high frequency radiation (eg, emitted from mobile telephone masts) whilst not interfering with the earth’s magnetic field,” and also about the benefits of “moon” timber, “harvested during the waning moon when the sap in the trees are at its lowest.”

But there is a lot to love about a pure wood environment. The Holz100 appears to cross the structural benefits of Cross Laminated Timber with the glue-free solid wood virtues of brettstapel, which makes a very interesting product.