Douglas Fir Tongue and Groove External Cladding

Our Douglas Fir Tongue and Groove External Cladding is tongue and groove cladding in Douglas fir, for external use.

About Douglas fir

Douglas fir with colour varying from pinks and browns to creams. Dark brown knots can loosen as the wood dries, and resin patches may ooze a little at first and in later hot summers.

Left untreated it weathers to silver grey.

A strong, hard-wearing softwood that's a popular alternative to oak cladding.

Profile and fitting

Boards fix together by inserting the tongue into the groove. They can be fitted horizontally or vertically; fit horizontal boards tongue uppermost so moisture runs off. Tongue 12 × 8 mm (Martyn long-tongue). On both 142 x 20 mm and 142 x 24 mm the visible face is 130 mm (Martyn ×20 plan geometry; ×24 is the same plan labelled thickness 24).

Grades and options

• First Grade: mostly clear of knots, with some knots up to 5 mm allowed and a small amount of sap on the underside only.
• Character Grade: knots, splits, sap, historic insect damage and other defects without limitation, as long as they don't affect usability.
• End matching (tongue and groove on the board ends) lets you place joints where they fall rather than on a batten, which speeds up fitting and reduces wastage.

Sizes and pricing

• 142 x 20 mm (visible face 130 mm; tongue 12 × 8 mm): from £25.49 per m² ex VAT
• 142 x 24 mm (visible face 130 mm; tongue 12 × 8 mm; Martyn ×20 plan geometry labelled 24): from £31.99 per m² ex VAT
• Supplied in random lengths between 1200 mm and 3600 mm.
• Set lengths are available for an extra charge using Set lengths (Cladding): surcharge £8.00 per m² ex VAT up to 3500 mm, £12.00 per m² ex VAT above 3500 mm. Add the same number of m² of set lengths as cladding.

Specifications

Finishing and aftercare

Supplied untreated. No treatment is needed, but to hold the colour for longer or add a weather-resistant finish, see our cladding treatments.

Drawings and downloads

Tap the drawing to open it full size.

Good to know

• Natural timber varies: expect some differences in colour and grain from board to board and from the photos.
• Boards left exposed to changing weather before fitting are likely to cup, warp and split. We suggest fitting between October and April where possible, within 7 to 14 days of delivery.
• Sizes are nominal and can vary slightly with moisture content.
• Not sure? Order up to two cladding samples first.
• Questions? Please contact our Sales Team on 01536 267107.