Renovation & Design

Roofing and deck building come together

Marc LaBossiere / Winnipeg Free Press

The torch-on roof process is completed, and holes centered in the eventual joists cavities lead to downspouts and to a main gutter.

Marc LaBossiere / Winnipeg Free Press

The reverse angle tapered-joists bring the framework back to level, ready for top decking. The drainage holes are visible at the end of each joists cavity.

Submitted / Carole Parisien

Marc LaBossiere hard at work securing the balusters one by one, from the balcony side.

The balcony deck is completed with Trex composite top decking and showcases the repurposed railing balusters.

The Reno Boss column has truly been a wonderful adventure. With 52 columns under my tool belt, I thought it apropos to start my sophomore year with a topic that leads me back to where it all began — my balcony.

In my first column — A Deck That Blends Old And New old wrought iron railings which had been salvaged from my old balcony by good friends and neighbours of mine, the Morin family, were repurposed on a deck I built for them sometime during the summer of 2016. This past week, a bit of repurposing of my own allowed me to complete my new balcony. It did, however, take some doing to get there.

After many months of planning, architectural drawings, engineer’s stamps, permits, materials orders and scheduling, it is with great pride and pleasure that I can report… the addition to my house is framed, and nearly exterior-complete.

One of the biggest challenges was designing the new corner balcony. Because the balcony is located above a portion of the new dining room area, several challenges needed to be addressed. The biggest hurdle being how to keep precipitation and moisture from creeping its way into the living space below.

It has been very educational, researching the ramifications of a flat roof. When first I inquired, the same term kept being tossed my way: torch-on roof. Upon further investigation, I began to understand the concept. A shingled roof is very efficient at allowing water to run off, provided the roof’s slope is adequate to encourage water to flow towards the gutter and downspouts.

With a flat roof, even with a slight grade it is a very different story. Shingles are installed in an overlapping manner. And if the overlap is higher than the grade over the distance of a shingle width, the water will pool — which is a recipe for disaster. With a torch-on roof, the entire roof becomes one big shingle. During installation, every section of the roof is heated (with a torch) just enough to allow the layers of roll roofing to melt and fuse to each other, at every seam, creating a watertight area throughout the entire roofline.

During the design stages, I had always intended to taper the balcony joists, inset slightly lower within the horizontally level outer framework, to allow for proper water drainage.

This was achieved by cutting down each balcony support joist, from 9¼ inches at the inner end to 7¼ inches near the outer edge, producing a two-inch grade over the 12-foot span of the balcony. Half-inch plywood was then affixed to the top of the support joists to create the flat roof surface.

At this stage, the construction reins were handed over to the torch-on roofing experts at Racka Roofing — it was quite a learning experience for this observer!

The Racka crew began by drying the flat roof sheeting with, yup — a flaming torch! By lightly caressing the damp wooden surface with a hot flame, you could hear the sizzle and see the steam rise.

They then prepped the plywood surface with a resin which allowed the first layer of roofing membrane to properly bond to the plywood. All roofing materials would completely cover the flat roof surface and overlap the surrounding frame edges, which are higher than the roofline (to create a fully sealed bowl).

The first roll roofing layer was torched to the initial membrane that had been bonded to the plywood. The second layer of roll roofing was then melted to the first. Once the procedure had been completed, the entire flat roof became one big continuous water catcher. Proper drainage was now essential.

I had modified my original balcony design to include 12 inches of cantilevered ends with an ever-so-slight reverse grade, which would allow for the appropriate drainage past the exterior wall edge of the living space below. Before top-decking could be installed, the roofline would need to be brought back to level.

This was achieved by cutting the opposing angle of the sloped main joists along each upper top decking support joist.

To prevent a breach of the torch-on roof when positioning these upper joists, no fasteners were used — these decking joists simply rest atop the torch-on roofline, held in place by silicone in various locations and the weight of the top decking. At the end of the joists, slightly past the cantilever, holes were drilled through the torch-on and plywood centered between every joist, short downspouts were mounted from below to provide an escape route for water.

These spouts channel water collected from every upper joist cavity into a gutter, cleverly hidden behind the balcony fascia, which directs the water to a main downspout and sends the water out into the yard at ground-level.

Trex composite was chosen as top decking, for two main reasons; Trex fastener clips have short enough screws not to breach the torch-on roof and membrane and the long life expectancy of composite ensures the top decking will not need replacing in the foreseeable future.

Once all joists were in position, the top decking was installed. The railing posts and fascia were fastened to the balcony framework and the railings were fashioned to match the other decks on the property.

This is where the recycling fun begins… the balusters which had been installed during the balcony upgrade when I bought the house, AND which replaced the old wrought iron railing which had been removed and recently re-purposed on the Morin deck, were also re-purposed this week on my new balcony. All this reuse brings a big smile to my face.

Despite having no knowledge of the torch-on roof process, my research proved it was the only roofing method available to satisfy my specific balcony requirements.

With living space below the balcony, proper water containment and draining is essential.

By providing drain-spouts at the end of every joist cavity, the water has nowhere else to go, but down and out. The balcony design is a success story — and the reuse of the balusters give this story a bit of romance.


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