What does a cheese sandwich have in common with your roof?

Why is a roof like a cheese sandwich?

Over the years I have noticed an increase in calls to provide quotes on roof replacements after the Labour Day long weekend here in Toronto. That’s understandable as most homeowners are busy with their familes during mid-Summer and then there is the distraction of “back to school” time of Late August/early September – or last minute vacationing.
However, delaying roof replacement until late fall is not ideal. You may have heard of shingles “sealing” after installation. So what is this “sealing of shingles” business anyways?

Sealing strip on a 3-tab shingle

Sealing strip on a 3-tab shingle

Shingles have glue strips on them. These glue strips allow the shingle on top to bond with the shingle below it after installation. Shingles need to seal with one another to prevent blow-off or wind damage. However, this adhesive strip requires warm weather and/or strong sunlight to heat the shingle, and activate the glue, so one can bond with the other. However, what most don’t realize is that shingles need time to settle as well. When fresh shingles are installed on your roof, they haven’t yet conformed to the shape of your roof.

“But my roof is flat” you say? Yes, and no.

The trusses, roof sheathing or boards on most homes create a distinct “wavy” pattern on your roof. This is not evident once shingles are installed, however, after a week of strong sunlight, the shingles will conform and the unevenness of the roof becomes apparent on most homes. This happens to be the moment when shingles have actually sealed with one another, and your roof protects your home.

If this doesn’t make sense, imagine a slice of cheese on your flat sandwich. Bread slice looks straight, and so does the cheese slice. Put them in the oven, and the result is anything but flat.


Exaggeration, sure, but it paints a clear picture.  So if you’re ready for a new roof, don’t delay!

Call 416-427-2437 for a free roof inspection from the best Toronto roofer in the city.