The Douglas fir originates from the western part of North America where it can be up to 100 m high in coastal areas in optimal growth conditions. It is usually 50-65 m high when cut down at an age of approx. 80 years. Frøslev mainly gets the Douglas fir from Germany, and we only use certified wood.
Douglas is characterised by its appearance with pale green fir needles and - depending on the age of the tree - grey-green to grey-brown bark.
The wood is divided into the white-yellow sapwood and reddish-brown heartwood. The wood is rich in resin, turpentine and tannins and has a straight fibre direction that makes sure that timber and planks do not twist while drying (unlike common spruce and Scotch pine). The branches gather in whirls as do pine and spruce, but if the growth conditions are good, the top shoots will be long, and there will be hardly any knots. Douglas is therefore well suited for orders in large dimensions, for example turbine arms or Vippefyret in Skagen (the above picture).
Douglas is also being processed into massive planks suitable for tables or especially shelves for do-it-yourself projects.
As the wood is rich in resin, resin pockets of a considerable size may occur.
Processing and protection
Douglas is easy to process with the right equipment. With structural protection, the wood is very durable. The durability is like a Scotch pine - and twice that of the common spruce. Douglas can, although it may be difficult, have the sapwood impregnated.
To the greatest extent possible, all wood must be protected by 'structural protection' which means that you plan and build in such a way that the wood is ventilated and water is drained off so that the tree can dry out.
Wood is a natural material and will eventually turn grey. It is a good idea to protect the wood with suitable wood preservatives when dry - either with flat paint finish or transparent wood preservatives.