TEP ROOF OY · PROJECT PLANNING GUIDE
Low-slope bituminous roof options
A request for a bituminous roofing quotation starts with the whole roof build-up. The name of the cap sheet alone does not define a suitable solution or the scope of work.
What are the options?
- Bituminous roofing uses a membrane combination suited to the project. The number of layers, product classes and fixing method are determined by the roof slope, substrate and exposure.
- Installation may involve torching, bonding with hot bitumen and mechanical fixing, for example. The jointing method and the fire risk associated with the substrate must be assessed separately.
How is the solution selected?
- The designer specifies the waterproofing application class and compatible products. Roof loads, maintenance traffic and equipment installed later affect the entire roof build-up.
- Confirm junction details, drainage and access for maintenance during project planning. The structure beneath the waterproofing and its condition are just as important to installation as the visible surface.
Include in your request for a quotation
- Attach the roof plan, area, slopes, roof build-up and known requirements. Identify any information that is still to be confirmed.
- List waterproofing, thermal insulation, the vapour control layer, eaves and associated work separately. This allows the quoted scope to be checked against the project requirements.
Use and design responsibility
TEP Roof Oy guide cards support project preparation and the definition of contract scope. They are not project-specific construction designs. The project structural designer is always responsible for checking the suitability of the solutions presented and adapting them to the project's structures, loads and requirements. Construction requires project-specific design and approval, together with the current manufacturer's instructions for the selected products.
Sources
An editorial compilation by TEP Roof Oy. The product- and system-specific source instructions must be checked for the selected solution.
- Kerabit: Low-slope roofs: membrane combinations and application classes Checked 12.10.2026
- BMI Suomi: Installing bituminous membranes on low-slope roofs Checked 12.10.2026
- Saint-Gobain Finland Oy / ISOVER: Low-slope roofs: system guide 07/2026 Checked 12.10.2026