T-Lock shingles are discontinued, but are still commonly found on Calgary roofs
A common sight on Calgary roof replacements
T-Lock shingles were once the favoured style of shingle for both appearances and performance. The roofing product slots together before being nailed to the roof deck. Because of this interlocking design T-Lock shingles have excellent resistance to wind.
T-Lock shingles are no longer installed on Calgary roofs for two reasons:
Hail damage to shingles in Calgary
- When slotted together part of the shingles are pushed up by 1/8″ inch or so where the layers overlap. This causes a cavity of a few square inches per shingle. During severe hail events houses with T-lock roofs are susceptible to damage in these areas and along the hips & ridges.
Gravel has come loose in the areas most affected by stress.
- T-Lock shingles are unsuited for use in closed valleys, where the overlapping design causes stress. Over time they become susceptible to leaks.