What Is a Gable Roof?

Aside from a “shed” style roof (one slope having a decending pitch); the gable roof is likely the most common roof design world- wide for homes.

The simplistic design of two opposing slopes having a similar pitch; creates a sense of balanced symmetry when viewing over a particular structure. In many older neighborhoods of Toronto and the GTA; the gable roof design is a common site.

During pre- war-times, these simple roof structures were meant for the common man’s housing, where often the wealthier of the day had homes with more complex roof designs incorporating hips , valleys, and cat-walks to appear more substantial architecturally speaking. Such designs were common during the craftsman period.

Many early Victorian homes  in Toronto, built circa mid 1850’a and into the early 1900’s seemed to favour the gable roof design. More upscale homes incorporated features which included dormers, finials, front aprons, gingerbread sytle molding work and columns to enhance the basic gable design.

Colonial homes also are reminiscent of gable roof design; often designed with opposing multi gable slopes and or staggered ridge/gable ends.

The look can be described as simple in more basic roof lines and more fanciful when combined with offset pitches ,dormers and roof slopes.

Even mid- century modern homes built in the 1950’s and 1960’s post war era, such as can be found in Don Mills and Scarborough and the “other suburbs” of what  was then simply Toronto; utilized the gable roof design. Characteristic were shallow roof pitches, and often different lengths of opposing slopes.

Perhaps you, like me growing up in the 1960’s, lived in a home with a gable roof. Ironically; I did not know then that someday I, (actually we) meaning our comrades at AVENUE ROAD ROOFING®, would have replaced the roofs on literally thousands of gable roof homes of every type and description possible.

One of the nice things about replacing a gable roof is that they are relatively straightforward once you are up on the roof. The big challenge when replacing many steep gable roof homes in the older neighbourhoods of Toronto, is  the ability to access the actual roof slopes and the challenge of how to handle the debris which results from stripping off such roofs.

Typically, there is little space between these houses, and modern home owners have typically invested in sophisticated landscapes often both in the front and rear yard areas of the home. In other words, sometimes applying the roof materials are the simplest part of the equation. Managing potential damage to client’s and neighbouring homes and gardens and pedestrian traffic areas can be the tricky part. That comprises a great deal of the cost to re-roof such homes.

But, the homeowner that has a steeper pitched gable roof can likely enjoy one of the longest life-spans for their roof simply because of it’s unobstructed shedding design.

Consider that when these homes were originally built, they had slate tile coverings. Slate that has remained on these houses for over one hundred years. While it became favourable in the early 1970’s to recover or strip the slates and apply asphalt shingles (largely due to cost considerations for many);today we are seeing a trend where many homeowners who are appreciating the value of their historical real estate, and are as a result, installing these life enduring materials again.

Our company is pleased to see this original architectural detail being embraced again because factually it represents a better option for durability, appearance, and our planet. Just consider the fact that natural slates installed correctly with authentic materials will endure one hundred plus years. That’s five trips to the landfill for average type shingles ;for just one house. Slate doesn’t off-gas, and slate can be returned to the earth. It is not comprised of oil or plastics.

Other enduring options for gable roofs include synthetic slates, cedar shingles and shakes, and the newest incarnation of fiberglass, laminate shingles.

Characteristic of gable roofs is having at least one (but usually two), gable end walls. To be period correct, many of the walls were covered in cedar shingles. The best restorative cedar for gable walls is 18” Number One, Certi- Grade “A”, Blue label Perfections. These uniform tapered cedar shingles are Western Red Cedar. They should be installed at a five and one half inch exposure. Feature courses may be incorporated to include rows of scalloped and or corner clipped cedar pieces.

This common detail can be found on literally thousands of homes in established Toronto neighbourhoods like the Beaches, High Park, Swansea, Rosedale, Lawrence Park,Wychwood Park, the Annex, and the Bloor West Village.

In the Victorian Era, cedar shingles on gable end walls were often dipped in coloured stain before application. To note is that dipping in stain is an arduous and time consuming process. It is preferable to painting over the face of natural cedar as it may be prone to cup or curl with long term exposure to the sun.

One of the inherent qualities of red cedar shingles and shakes is that they bleed natural oxides which repell insects, and as they  are known to resist rot. Cedar shingles also act as a good exterior insulator. For those who may not have the initial budget for a slate roof, using cedar shingles strategically on dormer walls and faces and end gables, and porch walls, maintains the original aesthetic of such homes and can blend beautifully with a good quality fiberglass laminate shingle.

With pride, AVENUE ROAD ROOFING® is one of three certified cedar roof installation contractors in the province of Ontario. The credential is provided through the Canadian Cedar Shake & Shingle Bureau™, whom are responsible for grading the cedar mill products and who issue the material warranties to homes and businesses that elect to install cedar shingle and shake products. Such cedar products are supplied by Canadian mills in British Columbia and are shipped world-wide from these Bureau approved, established local mills.

Straight forward gable roofs are designed with a ridge beam at the peak of the roof, and a series of common rafters extending down from the ridge beam to the eaves area fascia boards on opposing sides.

Standard rafter spacing is 16 inches on centre if using two by four or two by six dimensional lumber for the rafters. Two foot centres are permitted if using two by eight dimensional lumber, or if the roofs are constructed with pre-made trusses.

Trusses are characteristic of modern building methods where original Toronto gable roofs were typically “stick framed” by hand. If installing a metal roof over a gable design; two by four purloins are installed perpendicular to the rafters on two foot centres.This also permits the installation of a “cold roof assembly”, which permits the ceiling beneath the gable to be vaulted. Chords or collar ties secure the roof slopes to one another beneath the peak of the roof.

If one is incorporating a “complex” gable design to include a rear triangular slope or dormers with a hip design; framing detail will also incorporate the use of jack and hip rafters to complete the transition between a gable and hip roof sections, and or where valleys are incorporated such as at dormer transitions to the main roof deck with valleys.

Gable roofs were originally completed with boards or rough sawn planks. Modern building methods use plywood sheeting which is installed opposite to the direction of the rafters, and each sheet should be staggered at fifty percent to the sheeting placed above the initial course. Today, half inch plywood is the standard requirement. Some homes built in the sixties and seventies used thinner 3/8” plywood which required the use of “H” clips placed between roof sheets.

If one has an older gable roof with plank decking or boards; many fiberglass laminate shingle manufacturers will require the roofer to install plywood sheeting over the existing boards to provide for a clean, secure substrate. As old board or plank decks may have spacing between the boards, plywood provides for a continuous nailing surface.

In light of such requirements, the consumer can better appreciate why although these relatively simple gable design roofs are costly to repair or replace today; due to access and steepness of the roof slopes, tasks such as replacing rotted roof boards and handling materials can be precarious and slower that working on a simple bungalow. The good news is that gable roof designs tend to endure better over the long haul.

To learn more about roof designs, restoration and re-roofing of all types of roof configurations contact or visit: www.avenueroadroofing.com.