A Helpful Guide to Roof Shingle Patterns
Well over a century ago, old roofs of slate or wood were typically constructed of individual rectangular pieces, offset and overlapped to shed water. Occasionally, for added ornamentation, roofers would insert a few parallel courses of scalloped or beveled tiles into a roof of predominantly rectangular slate tiles. You can achieve the same effect using modern asphalt shingles’ designs and colors.
Ribbon coursing pattern of alternate courses of different roof tile profiles adds a decorative accent to some classic tile roofs.
During that period, the manufacture and subsequent installation of prepared asphalt shingles was accelerated when multi-tab shingles were made in a single strip. For decades, the three-tab strip shingle dominated the roofing industry with the characteristic geometric brickwork pattern it created on the roof.
Three-tab shingles are still widely available and used. Other shingle design patterns have come and gone including shingles that, once installed, simulated the look of fish scales or had interlocking T-shapes, scalloped and beavertail rounded tabs. Some were even diamond-patterned roof shingles.
This roof of interlocking shingles shows the distinctive “T” shape of each shingle. They were installed without using adhesives or cements because the shingles “interlocked” as they were applied. Although no longer available, interlocking shingles were quite commonly used in regions with high winds, due to their superior wind resistance.
IKO ArmourShield shingles from Europe offer a distinctive hexagonal shape, and also incorporate a shadow band for additional depth aesthetics. These shingles must be installed in a specific way to always yield the hexagonal pattern.
Three-tab shingles are most typically installed with a half-tab offset that yields the characteristic “brickwork” appearance; the cut-outs (also known as slots or keyways) separating the shingle tabs line up every other course. However, occasionally due to minor, unavoidable dimensional variations in the shingles or vagaries in the roof deck’s squareness, the cut-out alignment would sometimes meander slightly up the roof.
In order to address this, contractors in some markets – and some manufacturers – have promoted installation methods that introduce a degree of randomness, so that the cut-outs do not align. IKO endorses this application method as the preferred technique for this reason.
Shown is the classic look of three tab-shingles. This geometric brick pattern can be avoided by using the recommended random installation method shown below, which is easy to install and looks great.
At various times in the evolution of asphalt shingle designs, manufacturers have added overlay patch areas, thicker tabs and embossed patterns to simulate wood grain or added dimensional definition.
In the 1970s, two-layer and, in some cases, three-layer laminated shingles were developed. The primary aesthetic advantage of multi-layer shingles is the ability to have different colored areas of the shingle sharply contrasted and immediately adjacent to each other (since in traditional, monolayer shingle manufacturing there is always an area of transition from one colored area to the next).
Initially, these laminated shingles were made “off-line” by first manufacturing the individual pieces and then manually feeding them into a machine that combined the two pieces. As a result, those early laminated shingles were limited to one or two different cut patterns, and therefore had to be installed in very specific ways to avoid creating potential stripe patterns on the roof. In a worst case scenario, a faint “checkerboard” design could appear on the roof due to repeated patterns of lighter and darker shingle tabs.
Currently, laminated shingles are made “on-line” where ribbons of the different components are made continuously and then combined prior to being cut into shingle lengths.
The ribbons of roofing material have a sufficiently different and varying repeat pattern so that the resulting finished laminated shingles are essentially random in appearance and cut. The net result is that today’s laminated shingles, when installed according to the manufacturer’s instructions, typically have a random appearance, totally unlike the brickwork geometric repeating pattern of traditional three-tabs.
When installed according to the manufacturer’s recommendations, laminated shingles, such as IKO Cambridge, typically show no discernible repeating pattern on the roof, a look many homeowners desire.
Although IKO Armourshake shingles have a repeated pattern of tabs in each individual shingle, there is enough variety among the shingle tabs themselves that, once installed correctly, the human eye perceives a pseudo-random roof design.
It is important to install shingles according to the manufacturer’s instructions. Some roofing contractors may incorrectly assume that all laminated shingles are installed the same way, with the same exposure and the same offset, regardless of the manufacturer.
While the modern laminated shingle design is somewhat forgiving of improper installation offsets, shingle manufacturers have designed their shingles precisely. Deviating from the printed installation instructions risks creating a roof pattern the homeowner might not like.
The appearance of patterns can come from either the dimensional layers (the shingle tabs/teeth) aligning unfavorably or from the colored granule areas creating a checkerboard-like pattern.
Although modern laminated shingle installation usually intends to yield a random, non-repeating roof appearance, some premium shingle brands are designed to give a relatively uniform, repeating look.
One such product is IKO Crowne Slate, a full two-layer shingle that simulates the classic look of old world slate. Just as slate roofs gave a square tile look, so too does IKO Crowne Slate, but without the need for additional structural support and sophisticated installation training.
IKO Crowne Slate ingeniously simulates the natural slate look in that each color blend incorporates an infrequent “splash” of a uniquely contrasting tile color. When this accent color on the roof picks up on the color of exterior elements such as brickwork, stone facing or wood trim, the overall effect is unusual and truly stunning.
With a combination of bold, distinct contrasting color drops and large square tile-sized tabs, IKO Crown Slate emulates the pattern and look of a natural slate roof.
Whether you prefer a repeatable geometric design on your roof or a more random natural look, select the shingle from actual samples and hire a professional roofing contractor who will correctly follow the manufacturer’s installation instructions.