Fir
Fir
Abies alba
Other names: Silver fir, Sapin
General description
Fir is a typical tree growing in the shadows of higher trees. It is distributed over the whole of Europe, has a straight trunk and grows to a height of about 40 m
Wood description
The colour is white with a little tendency to grey-violette. Heartwood is not distinct from sapwood. The texture is fine to medium according to growing speed. There is no resin in the wood. The wood is similar to spruce: soft, low in weight and has medium density. Strength properties are good.
Sawing and machining is easy, also assembling. Fir also has a slight tendency to split when nailed.
Common uses
Fir and Spruce wood are often mixed for structural end uses, indoors and outdoors: general carpentry, interior construction, windows and doors.
| Physical characteristics | |
|---|---|
| Density (at 12 % moisture content) | 441 kg⁄m3 |
| Total longitudinal shrinkage | 0.1 – 02 % |
| Total radial shrinkage | 3.8 % |
| Total tangential shrinkage | 7.6 % |
| Equilibrium moisture content | |
| (20° C⁄ 37 % rel. humidity) | 7.1 % |
| (20° C⁄ 83 % rel. humidity) | 16.9 % |
| Mechanical characteristics | |
| Modulus of elasticity under bending | 11000 N⁄mm2 |
| Modulus of rupture under bending | 73 N⁄mm2 |
| Tension strength | 84 N⁄mm2 |
| Compression strength | 45 N⁄mm2 |
| Brinell hardness perpendicular to the fibres | 14 N⁄mm2 |
| Janka Hardness | 1.8 kN |
| Nail withdrawal strength in N per mm depth and mm diameter | 5.0 N⁄mm2 |
| Natural durability and treatability (according to en 350-2) | |
| Fungi | Class 4 –poorly durable |
| Dry wood borers | susceptible |
| Termites | Class S susceptible |
| Treatability | 2 – 3 poorly to moderately permeable |
Natural durability is based on mature heartwood. Sapwood must always be considered as non durable against wood destroying agents.