Douglas Fir Tongue and Groove Cladding

Douglas Fir tongue and groove cladding is available in the following profiles:

• IWC1 - 19mm x 145mm overall, with a 135mm face - For horizontal or vertical fitting
• IWC2 - 19mm x 95mm overall, with an 88mm face - For horizontal or vertical fitting
• IWC3 - 19mm x 142mm overall, with a 125mm face - For horizontal or vertical fitting
• IWC4 - 19mm x 145mm overall, with a 125mm face - For horizontal or vertical fitting
• IWC5 - 19mm x 145mm overall, with a 125mm face - For vertical fitting only

Most of these profiles are flexible enough to fitted either vertically or horizontally barring IWC5, which is only suitable for vertical fitting. If you want to fix your cladding with "secret nailing", then you can select our IWC3 profile.

If none of our standard profiles meet your requirements, please feel free to send through a drawing of the profile you need, and we will be happy to get a price for you.

The 85/15 Clears grade Douglas Fir we supply is a light reddish-brown and has very few knots. This modern, uniform look is very popular and with the help of some great machining this traditional material can be pulled into the future.

The machined boards we supply in our Douglas Fir tongue and groove cladding are 3m and longer. These lengths are supplied randomly however if you want certain lengths please call us on 01889 279 018 or jump on the chat and we’ll be happy to see if we can get the lengths you need.

If your lengths are available, please enter them in the “Special Instructions” box on the checkout page and we’ll process your order accordingly.

Treatments

Most people leave their timber to go the traditional silver-grey in the sun. We recommend talking to www.wood-finishes-direct.com if you would like to treat your timber. If you do decide to treat your timber, it needs to be treated all the way round including the ends to prevent moisture getting in at all.

Fitting Guidance

These fitting guidelines are only a rough idea on how to fix your tongue and groove cladding. We do recommend you employ a professional who has experience fitting tongue and groove cladding.

Be sure to read our treatment guidance as treatment needs to be applied prior to fixing your cladding

Breathable Membrane

Consult a fitter to determine if your scenario would require the fitting of a breathable membrane between your wall and the cladding. This membrane stops rain getting to the wall, but allows moisture to escape, helping to prevent internal condensation and mould that can come with it.

Treated Softwood Battens

Treated softwood battens (available from our cladding accessories pages) are most commonly used to fix to the wall (or on top of the breathable membrane) to then fix your cladding to. If you are fixing your cladding horizontally, your battens need to be placed vertically, at around every 600mm (60cm), and vice versa.

Fixing

** Whether you use nails or screws, it's important that they are stainless steel, or silicone bronze ARS, so that the natural tanins in the timber will not corrode them. Never use iron nails for fixing timber.

To help stop the wood from splitting we recommend pre-drilling the timber and then holding it with the screw or nail head when you fit the board to the batten. Look to leave a 3mm gap between the boards, rather than butting them up tight like flooring, to account for any moisture movement and make sure that the tongue is facing upwards otherwise moisture will start gathering in the groove of the profile.

You can also use nails, preferably ring-shanked for extra grip, and again stainless steel so they don't corrode. For lower-density species like cedar, consider using nails with larger heads so the cladding doesn't pull through.

You can fit IWC 1,2,3 and 4 vertically or horizontally depending on the look you want from your timber. Whilst technically you can fit IWC5 horizontally, water can sit in the square channel, which is not recommended.

With each new row of cladding you add, it's preferred that you stagger the joins between each board so you don't create a visible seam.

As already stated, these are just ideas to get you thinking about installation and you should consult a professional installer before fitting your cladding as every scenario is different.

All our claddings are provided untreated. Fresh sawn timber claddings are best left untreated and to go silver grey. There are a wide range of optional treatments available for different species of timber and we recommend talking to the excellent team at www.wood-finishes-direct.com, who know the most up-to-date information on all the newest treatment products.