Cedar Bevel Siding: Sizes, Overlap and Installation

Cedar bevel siding is horizontal siding made from boards that are thicker at the bottom edge than at the top. Each course laps over the one below it, so the wall sheds water like a stack of shingles and shows a crisp shadow line at every course. It's what most people picture when they say "clapboard," and western red cedar is the traditional wood for it because it resists rot and holds paint and stain well.

Common sizes

Bevel siding is sold by nominal thickness and width. A few common profiles:

Nominal size	Butt (thick edge)	Typical exposure	Look
1/2 x 6	about 7/16 inch	about 4 1/2 to 5 inches	Traditional narrow clapboard
1/2 x 8	about 7/16 inch	about 6 1/2 inches	Classic, slightly bolder
5/8 x 10 or 3/4 x 10	thicker butt	about 8 1/2 inches	Wide "bungalow" siding with a deep shadow line

Exposure is the part of each board left showing. Overlap is the board width minus the exposure; keep at least an inch of overlap. Many installers set the exposure so the courses line up with the tops and bottoms of windows, which makes the trim work look intentional.

Nailing

Like all wood siding, bevel siding has to be able to move with humidity.

• Nail once per stud (or support), into the board just above the top edge of the course below, so the nail misses the board underneath. Two boards nailed together can't move, and one of them will split.
• Use stainless steel or hot-dipped galvanized siding nails. Plain steel reacts with cedar's natural extractives and leaves dark streaks.
• Nails should go into solid wood (studs or sheathing approved for nailing) deep enough to hold, and should be driven snug, not countersunk.

Rainscreen and back-priming

• Rainscreen: furring strips or a drainage mat between the water-resistive barrier and the siding leave a small gap so water can drain and the back of the boards can dry. It adds years to the finish.
• Prime all sides before installing, including cut ends. Back-priming keeps boards from absorbing moisture from behind and cupping.
• Leave small gaps at butt joints and seal them, or use a scarf (angled) joint, and stagger joints so they don't line up from course to course.

Smooth or rough face

Many bevel boards have one smooth face and one rough-sawn face. Install rough side out for stain; it holds stain longer and hides surface checks. Install smooth side out for paint, with a stain-blocking primer to stop cedar tannins from bleeding through.

Bevel siding vs. other cedar siding

	Bevel	Board and batten	Shingles
Direction	Horizontal	Vertical	Overlapping courses
Look	Classic clapboard	Farmhouse, modern rustic	Cottage, coastal
Install speed	Medium	Fast	Slow
Repair	Replace one board	Replace a board or batten	Replace single shingles

Maintenance

Look at the south and west walls every year; they weather fastest. Restain every 3 to 5 years for semi-transparent stain, longer for solid stain, and repaint when paint starts to chalk or crack. Keep sprinklers and soil off the bottom course, and keep at least 6 inches between the siding and the ground.