Wood from Alaskan yellow cedar, Northern white cedar and red cedar is made into shingles. Each kind of cedar has particular properties that could affect its use on interior walls. Alaskan yellow cedar is a fine-textured wood with a straight grain, and it is strong and extremely resistant to decay. It is best known for the silvery gray color it develops as it ages outside, but it can be used on interior walls. Northern white cedar is resistant to moisture, mold, decay and insect damage, and it accepts paint and stain better than red cedar. Its unusual cell structure allows it to trap tiny pockets of air, giving it insulating value. Red cedar also has insulating properties, but it’s more likely to split than white cedar, and it resists painting and staining. Its rich coloring and resistance to decay, however, make it a common choice for homeowners.
Red and Alaskan yellow cedar shingles are made in four grades, but usually only grades No. 1 and No. 2 are used on walls. Both grades are available rebutted and rejointed, which means the shingles have parallel edges and square butts that give them a uniform appearance. Northern white cedar shingles also are available in four grades, marked A through D. Grade A, which is premium quality, and Grade B, which is standard quality, are usually used on interior walls. Rebutted and rejointed Northern white cedar shingles are available.
If the interior wall can support fasteners, then you may attach cedar shingles directly to the wall. Otherwise, apply them over furring strips. Two nails or staples are used in each shingle. Stainless steel nails or fasteners are best because inexpensive nails might cause a rust line to bleed down the shingles. Position shingles so the nail heads are hidden by the next course. Don’t nail the head of the nail all the way into a shingle or it will crack when the shingle expands and contracts as the humidity level fluctuates.
Shingles on interior walls don’t need the same protection as those installed on exterior walls unless they’re used in bathrooms or other areas with a high moisture level. In those places, use an exterior grade finish. Applying a transparent finish such as shellac or wax keeps shingles looking “natural." Latex- or oil-based paints can be used to tint shingles, or they can be applied over a stain-blocking primer. Oil-based stains and penetrating wood stains also can be used. Remove dirt and dust before applying a product, and verify that the finish is for interior use.