Wood Sidewall Shingles – Mastering the Basics
I’ve always loved the look of a roof or wall clad in shingles or shakes. There is something striking about the inherent texture and the resulting pattern of so many individual pieces of wood blended carefully together for utility and effect into one surface. While they can be used as a roofing material, wood shakes and shingles also lend themselves particularly well to siding applications in their ability to create patterns and accents, which lend a building fade a sense of craft and distinction. We’ll explore some of the variations in material available and the preliminary terminology and knowledge required to undertake your own project, and I’ll offer a recent project of mine as an example.
Dunkin marks a line directly on his chop-saw. He then lines each shingle to the line, makes the first cut, flips the shingle and makes the second cut.
Position the first two courses 1" lower than the bottom of the gable to form a drip edge. You’ll also notice a string set up to keep the first course straight.
A Temporary Guide
Use low-permanence chalk to snap consistent lines on each course. This will help keep each course straight, and will speed work.
A torpedo level keeps the shingles aligned, while a piece of ¼" ply keeps the keyways even.
Though it’s not an exact science, Dunkin settled on a 5 ¼" exposure to match the existing shingles.
Predrill small face shingles with a small drill bit, then nail carefully. Be sure to not drill into the cladding below it.
Enviroshakes are a composite roofing shake made of recycled rubber tires, wood fibre, and recycled plastic pop bottles. They have the same look and feel of wood shingles, and can be easier to work with in certain situations.
Aluminum siding (below) on this sidewall was removed to find existing wood shingles (above). Though not everyone is going to be this lucky during their reno, the differences are visually striking.
Shake or Shingle?
Traditionally wood shakes were created by hand-splitting sections of log with froe and caul, resulting in a relatively thick, tapered, rustic piece of wood. Wood shingles, on the other hand, were sawn instead of split and, while tapered, were thinner than their shake cousins. Today, shakes are still thicker than shingles, but shakes are available sawn or split, or with one face sawn and the other split. Shakes, measured at the butt end, are usually between 1/2″ and 3/4″ thick, while shingles are a thinner 3/8″ to 1/2″ thick. Being accurately sawn, shingles have always been more refined than shakes and therefore more versatile for projects that combine function with more polished aesthetics. See the Grades of Shingle inset for more information on the quality gradations available.
Sidewall Wood Shingle Basics
Wooden sidewall shingles are affected by moisture in different ways. They are susceptible to changes in relative humidity and expand and contract seasonally. They are also affected by wetting from rain and snow on their exterior surface.
In either case, the expansion and contraction differentials between the inside and outside surface can cause cupping, cracks or the loosening of a finish over time. The best way to mitigate the damages of moisture to wood shingles is to provide ventilation behind the shingle, by placing the shingles over horizontal strapping or by using a synthetic mesh-like underlayment like Benjamin Obdyke’s Cedar Breather or Home Slicker plus Typar. Another way, if the shingles will be painted, is to prime all sides of the shingle to reduce the swelling and shrinking when in contact with moisture or humidity. You can dip them in paint or stain and roll the excess finish around with a roller and hang them on a clothesline to dry.
Porch Gable Wall Restoration
I recently undertook the restoration of a porch gable facade on a Victorian-era 2 1/2 storey house. The original cedar shingles on the porch gable had been replaced at some point with black asphalt shingles and the owners wanted to restore the sense of integrity to the front view by matching the cladding of the front porch gable to the larger gable above it. Those original shingles, while a bit worn and cupped, had stood up well over the century they had been in place and simply needed some fresh paint. The shingles on the gable facade I was matching were octagonally cut and uniform in width. My first task was to prep the shingles.
I used #1 Perfections (18″) for this project because I wanted a higher-end grade of shingle that would be dimensionally stable and free from defects. I could also have used a #2 grade, especially because the shingles were to be painted, but they weren’t available at the time of purchase.
Emulating a Pattern
With a symmetrical pattern, you must compose it of identical pieces, ripped to a uniform width. It’s possible to buy shingles that are pre-milled and finished, but I had very specific sizes I needed, so this wasn’t an option. When the bundle of shakes comes apart, you’ll see how wet the individual pieces are in the center, and therefore prone to shrinking. The nice thing is they don’t take long to dry out because they’re thin. After a week or so indoors and spread out they were ready to be milled. They were ripped to the same width as the original shingles, and then the ends were squared with a chop saw.
To cut the octagonal end, I adjusted the 45¼ cuts so that all three of the octagonal faces were the same length. With a simple pencil mark on my chop-saw at zero degrees as a reference for the butt end of my shingle, I would make one 45¼ cut, flip the shingle, and after lining it up with the pencil mark I would make the second cut. The first two courses of shingles needed to have no octagonal cuts on them, so I made sure I had enough of those set aside. I factored in close to 10 percent waste on this project because I was working with a triangular shaped wall. The shingles were painted on all sides with one coat of paint before being installed to help seal them against humidity and wetting.
Wear a Dust Mask
As a safety note, Western Red Cedar dust and the fumes emitted, particularly when the heartwood is cut, are powerful irritants and can induce asthma attacks and even long-term respiratory damage if breathed. Always cut outdoors and use a respirator with an organic vapour filter to protect yourself and others.
There are lots of rules that you need to get a handle on before you begin; some are specific to your application and to the specific shingle you are laying, and some are general. Your best source is The Cedar Shake and Shingle Bureau (cedarbureau.org), which has lots of helpful illustrations available online, but I’ll go through the parameters I was working under here.
Shingles install in courses from the bottom up with the first course being composed of two layers of shingles. There is a space of 1/8″ to 1/4″, called a keyway, left between shingles to allow them room to expand and contract. The doubled course of shingles ensures that when the second layer is laid directly overtop, there is shingle visible behind the keyways of that second layer.
Exposure, Nailing, and Offset
I let the first two courses begin 1″ lower than the bottom of the gable to form a drip edge, and set up a string to keep the first course straight. I used a piece of 1/4″ plywood as my keyway spacer to keep the spaces between shingles uniform and a torpedo level to check for plumb every so often. The first course was a double course and then I chalked a line for each course after that keeping my exposure consistent and checking for level every couple of courses. In this pattern, because each of the shingles was the same width, each butt end centers over the keyway below it for easy reference. I settled on a 5 1/4″ exposure to match the existing shingles.
The nails I used were hot-dipped galvanized 3d box nails 1 1/4″ in length, which don’t split the shingles and feel more like pins than nails. When installing shingles, nails should be 2″ above the exposure line and 3/4″ in from the edge of the shingle and should be driven flush with the surface of the shingle. To protect against moisture entering a keyway, the joints between shingles should be offset 1 1/2″.
Along the roofline I set a ripped-down 2 x 2 board, which was the depth of the leading edge of the shingle courses to provide a flat nailing surface for a future piece of trim, which would cover the exposed nails on the shingles.
Make sure you use a low-permanence chalk if you don’t want chalk lines to stay visible forever. One handy technique is to use a straight board tacked lightly to the course beneath to reference where the butt ends will rest. Because each course got successively shorter on this project, this wasn’t feasible. Another helpful tip on a rectangular wall would be to use a story-pole with course exposures marked on it to maintain consistency and reduce the likelihood of errors being made while measuring repeatedly or to ensure courses on different wall faces are identically spaced. To reduce the tendency for small pieces of shingle to split when they are being nailed in, predrill the face shingle with a small drill bit, but don’t drill into the cladding below it, then nail carefully.
Shaking it Up
Not only are there many options in terms of patterns and layout, but you’re also not limited to cedar. Shingles are also available in pine and pressure-treated wood, and in a variety of shapes and finishes to give you lots of options. Several years ago I shingled the second storey sidewalls of my home with Enviroshakes, a composite roofing shake made of recycled rubber from tires, wood fibre, and recycled plastic from pop bottles. Textured like a split cedar shake Eviroshakes weather over time to a silvery grey similar to weathered cedar. Warrantied for 50 years, they are maintenance-free (you can’t paint them even if you wanted to!) and can be removed easily and reused as I’m currently finding while building an addition to my home.
Sidewall shingles and roofing have the ability to add visual interest and complexity to a building, and to restore a sense of historical integrity to buildings that once featured wood shingles. A couple of years ago I had a client who wanted to restore the gable of her home to the original shingles, or as close as we could reconstruct it. Sometime during the ’70s, someone had sided it in aluminum siding and it lost a lot of its character. Imagine our surprise when I removed the siding and found the original cedar shingles beneath. We were able to just replace the small slanted section of roof at the bottom of the gable with shingles, and restored the small “roof” above the windows. Paint and caulking did the rest and the transformation of the facade came about with relative ease. A comparison of before-and-after photos illustrates the way that texture and detail can transform an area from humdrum to spectacular.
Grades of Shingle
The Cedar Shake and Shingle Bureau has a grading system for Western Red Cedar shingles that delineates four grades of shingle. Shingles are sawn into lengths with corresponding names: 16″ (Fivex), 18″ (Perfection) or 24″ (Royal).
Number 1 Blue Label shingles, which are sawn entirely out of heartwood, are completely clear of knots or defects, and sawn out of edge grain. As the highest grade, these shingles are the least likely to warp, split, or crack and have the most uniform colouring.
Number 2 Red Label shingles are guaranteed to contain a portion of clear grain (i.e., 11″ on 18″ shingles) and may contain a small amount of sapwood or flat grain.
Number 3 Black Label are considered a utility or economy grade because they contain less wood that is clear of knots or defects (6″ on 18″ shingles).
Number 4 Undercoursing shingles are meant only to go under other shingles on sidewalls and are not to be used on roofs.