Douglas fir has the highest strength rating of any softwood and is a cost effective choice for timber framing. Its strength properties are similar, but native Douglas fir is 30% lighter in weight. As a structural timber, Douglas fir offers a cost effective alternative with the price for an equivalent section being approximately half that of green oak.
Species
Pseudotsuga menziesii
Source
UK
Surface finish
Sawn or planed
Sections available
Up to 9.5mt long. Up to 450mm x 450 section size
Green Douglas Fir Beams
Species
Pseudotsuga menziesii
Moisture content
Wet (green)
Surface finish
Sawn or planed
Sections available
Up to 9.5mt long. Up to 450mm x 450mm section size
Grading
Graded under BS4978
Grades available
Visual grade & Equivalent mechanical grade
SS C24
100mm minimum smallest dimension.
SS C18
Smallest dimension less than or equal to 100mm.
GS C16
100mm minimum smallest dimension.
GS C14
Smallest dimension less than or equal to 100mm.
Durability
BS EN 350 Moderately Durable (Heartwood only)
Weight
Approximately 700KG / M3 when wet and 590KG / M3 when dry.
Shrinkage
Less than 0.5% along the length and between 5% and 7% across the section
Modulus of elasticity
Green Douglas fir E = 6,500 – 8,000 N/mm2
Generally easy to work when green although knots (especially when loose), can create problems when cutting joints and holes. Knots can become loose as the wood dries out.
Nothing problematic.
Not generally affected by any wood boring pests.
All fixings used in conjunction with green oak should be stainless steel.
Surface spread of flame class 3 (BS 476-7)
Vastern Timber is not able to offer structural engineering services or advice on section sizes required for particular applications.
While the utmost care has been taken to provide accurate information, Vastern Timber shall not be held responsible for any consequences arising from any errors or omissions on this website nor for any damages resulting from the use of the information.