I have a customer who has numerous tamarack trees that he would like me to saw into board and batten siding for his barn. Is this species suitable for this application? Is it rot resistant enough for outdoor use?
(Sawing and Drying Forum)
From contributor K:
Regarding decay resistance, tamarack is a step up from pine or fir. The problem with tamarack is the windshake. The homesteaders made rails out of tamarack because it splits readily. If you can get clean wide boards, the home will have a unique look and weather well. Perhaps if you milled it thicker (5/4)? I have split tens of thousands of fence stays from tamarack and have learned that it splits best from the top down. Trying to split from the bottom up leads to the material flaking off along the grain. I do not know if it would help at all. Based on my splitting experience, I would recommend that you mill from the top down. Milling or splitting from the top down seems to better manage the species inherent need to split.
Did you know that tamarack is nearly always a component species? Usually it is less than ten percent of a forest stand. It rarely grows in solid groves over the landscape like pine or fir. That is certainly the case in eastern Oregon. We have to hunt to find the pockets when we want fence material of firewood.
Here in eastern Canada, tamarack is as you mentioned - a component species. It is seldom managed for because there is little market for it except for bridges and because it needs to be dried separately from spruce or fir. There is, however, a growing demand for tamarack flooring.
I plan on using tamarack for some mouldings and kitchen cabinets inside the house. I have used construction grade spruce plywood with one good face. I have sanded that face and added a 1 inch deep solid tamarack edging on every visible edge. I have also used a piece of 2" x 2" tamarack on the front of my cabinet top. The top is covered with tiles. The piece is grooved to the thickness of the plywood receiving the tiles. The whole feels and looks rock solid. The problem I have had is that many boards I want to use have dried too fast and were not properly stickered and piled to prevent deformations during drying. There are lots of warped boards in my pile.