What are the properties of wood shakes and shingles?

MMH Expert_Matt T EXPERT April 24, 2008

Wood shingles and shakes are usually western red cedar, white cedar, redwood or cypress. Other materials such as pine may also be used. The first materials mentioned have a natural resistance to rot. Pine shingles are usually pressure treated to enhance rot resistance.

The most popular shingle or shake is western red cedar, which comes in four grades:

• #1 Blue Label is 100 percent heartwood, 100 percent edge grain and 100 percent clear (no knots).
• #2 Red Label allows some sapwood and some vertical or flat grain. This material is recommended for walls, although you will see it on roofs in many areas.
• #3 Black Label shingles should be clear for the first 6 inches up from the butt on short shingles and the first 10 inches up from the butt on 24 inch shingles. Flat grain and sapwood are permitted. The shingles are often thinner than #1 or #2. This material is suitable for outbuildings such as garages, or the first course of a two-course application.
• #4 Undercoursing shingles are only for the first course in a two-course application, or for shims.

Shingles come in 16-, 18- and 24-inch lengths. A double layer of shingles is usually used on siding. (In the Roofing Module, we talk about using three layers for roofing.)

Shakes are typically 18 or 24 inches long. Shakes 32 inches long are sometimes available. Shakes may be taper-split, hand-split and resawn, straight-split or tapersawn.

Shingles or shakes can also be mounted on a piece of plywood or fiberboard to make up panels. The panels are typically four feet or eight feet long. They are installed much like siding boards.

Corners on shingles or shakes may use corner boards, overlapped corners (alternating courses of shingles) or mitered corners. Overlapped (woven) and mitered corners are loose and should be underlaid by a flashing material. This is typically a metal flashing that extends three to four inches beyond either side of the corner.

Nails for shingles and shakes may be copper, stainless steel or hot-dipped galvanized. Electroplate galvanized nails are not recommended because they don't last as long. Staples are commonly used in some areas, but are considered inferior in others. Using two nails per shingle is common, roughly one inch in from each side. The nails are usually 1 1 /2 inches above the butt of the overlying shingle or shake.

Nails for shingles or shakes can't all go into studs, as they often do on board siding. The studs are 16 inches apart. Shingles and shakes are 3 to 12 inches wide. As a result, sheathing has to be substantial, so that the shingles or shakes will be well secured.

Building paper or housewrap is typically used between the shingles or shakes and the sheathing.

Now we'll look at some common problems with wood board siding and shingles and shakes.