A number of different types of asphalt based flat roof systems are installed in BC. The most predominant of these are “tar and gravel” and SBS Modified Bitumen “torch-on” roofing systems. The older of these two types, “tar and gravel” roofing has essentially been phased out in favour of SBS “torch-on” roofing. Currently it is the replacement of older tar and gravel roofs, which have generally provided effective service lives of 20-25 years, that represents the largest local re-roofing requirement. However, as torch-on roofing has been proving itself only capable of providing short service lives of approximately 15 years, replacement of this type of roofing is beginning to become an increasing requirement.
Despite its many failings and issues, torch-on roofing continues to be heavily promoted by the BC roofing industry. While industry figures are not readily available, “torch-on” roofing likely continues to account for over 70% of BC low-slope installations, this being almost exactly opposite to rapidly declining use of torch-on roofing in the rest of North America.
The primary issues concerning “torch-on” roofing are as follows:
- Poor Investment: Torch-on roofing represents a poor investment due to high installation costs in combination with the provision of short service lives.
- Restricted Warranties: Because “torch-on” roofing does not stand up well when subjected to ponded water, it comes with significant manufacturer warranty restrictions.
- Serious Fire Risks: Because powerful propane torches are required to install “torch-on” roofing, it poses a serious fire risk when being installed. What’s worse, torch caused roofing fires can occur when flames are allowed to lick down into attics to then catch and smolder for hours, often into to middle of the night before finally erupting, This was the case with the shown New Westminster torch-on roofing fire, the City’s worst in over 100 years.
- Environmentally Harmful Product: Torch-on roofing is by far the most environmentally harmful of the available alternatives to manufacture, and as it is not recycled must go to landfills to leach asphalt, styrene and other harmful modifier chemicals into the environment for centuries.
For the forgoing reasons TechPro does not offer to install torch-on roofing and is an advocate of seeing its use in BC either totally banned or at least brought into line with the rest of North America. For a more detailed explanation of the foregoing points see the
article “Reasons Torch-on Roofing Should Be Banned“