Flat roof systems
Having to select a flat roofing system can seem complicated and time-consuming for a building owner or facility manager charged with making such an investment. There are some key things to understand when facing such a task.
The first step is to learn what waterproofing assembly and insulation combination you have existing on your building.
This can result in savings if for example there is salvageable thermal insulation beneath the existing waterproofing layer. If you are fortunate to have this circumstance; you may be able to “skin” the existing roof by removing the current waterproofing layer, and replacing only insulation that is wet beneath the membrane. A new waterproofing assembly can then be installed providing well over a decade of dependable performance. One may also be able to add thermal insulation under this circumstance, to lower heating and cooling costs, therefore reducing the costs of operating the building.
If however it is discovered through inspection, that the existing roof may have issues such as corroded steel pan substrate or rotted wood decking, or the lack of a proper vapour retarder layer; then the roof should be completely removed to reveal the substrate beneath.
This becomes the opportunity to design and build your roof to today’s building code and energy efficiency standards.
During the design phase, building usage must be considered for example a cold storage facility will require differing specifications from an office building that has a large walk-out terrace. A food processing facility will require special interior protection measures to avoid dust infiltration during the re-roofing process.
Once design requirements are understood, then a suitable water-proofing membrane or options thereof can be narrowed down.
All modern water-proofing assemblies have their advantages and disadvantages. Climate, drainage, and sustained roof traffic should be factored in when selecting a waterproofing system for flat roofs.
In our region of Canada, there are a number of waterproofing systems that are commonly considered.