TEP ROOF OY · PROJECT PLANNING GUIDE
PVC roofing options
PVC roofing is one waterproofing option for a low-slope roof. Specify it as a complete system, including fixing, junctions and the underlying layers.
Choose a system for the project
- PVC membrane seams are joined by hot-air welding. Depending on the system, fixing may be mechanical, bonded or vacuum-based; these methods cannot be interchanged without checking.
- Design mechanical fixing for wind loads and match it to the structural deck. Include perimeter zones, penetrations and other junctions in the design.
Compare the entire roof build-up
- Check compatibility with the insulation, existing roof covering and other materials in contact with the membrane. A separation layer may be needed; confirm this in the selected manufacturer's instructions.
- Hot-air welding does not require an open flame. Site safety procedures, substrate suitability and the applicability of classifications must still be established for each project.
Complete the request for a quotation
- State whether the project is new build or refurbishment, the area, slopes, structural deck and existing roof covering. Include the roof equipment layout and the designer's requirements.
- When comparing bitumen and PVC, keep the contract scope the same: insulation, the vapour control layer, junction work and handover documentation must also be included.
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.
- Protan: Standard overlap installation system Checked 12.10.2026
- Protan: Exposed roofs: PVC roofing systems Checked 12.10.2026
- Sika: Sarnafil G 410-20 L: substrate compatibility Checked 12.10.2026