Bitumen is a popular choice among roofing experts due to its waterproofing properties. It is available in various systems; single, dual, or multi-layered that include vapour barriers, insulation, underlayers, and capsheets to protect against UV degradation.
Bitumen’s durability makes it ideal for refurbishment projects, from simple patch repairs to complete replacements where the existing bituminous or asphalt systems have exceeded their lifespan.
Choosing the right bituminous membrane can be challenging, given the variety on the market, but there are two main types that should be considered in the UK, elastomer (SBS) and plastomer (APP).
SBS-modified bitumen is made from styrene butadiene resins with synthetic rubber, known for flexibility, ease of installation, and suitability for varying climates and building movement.
APP-modified bitumen uses plastic (atactic polypropylene) for a more free-flowing liquid that requires more heat to install, making it ideal for warmer weather.
SBS is often preferred for refurbishment projects, especially when work needs to be done quickly and occupants are present. It is also better suited to the UK’s climate. However, choosing the right material is just one part of the process, several other steps are necessary to ensure the correct application.
Roof refurbishments should start with a survey to assess the roof’s condition. If the roof is in poor condition a full replacement is recommended, if not, an overlay might suffice. Insulation should be selected based on compression strength to bear the loads imposed by the building’s use, with considerations for upstand heights and roof gradients.
At SOPREMA, we offer various bitumen waterproofing solutions for different refurbishment needs, such as:
- Sopralene Flam 250 AF
An SBS-modified membrane with polyester reinforcement, finished with slates, and a protected lower surface. - DUO HT 4 AGR/F C180 FC
A double bitumen coating with fire-retardant additives, high mechanical resistance, and UV protection. - DUO HT 4 AGR/F C180 FC MECANO
A mechanically fastened single-layer waterproofing system. - DUO HT 4 AGR/F C180 AERO FC
A single-layered membrane with a vapour-pressure and tension dispersion system.
These waterproofing roofing systems come with warranties ranging from 15 to 35 years on warm roofs and are compatible with PMMA, suitable for projects with safe-to-torch policies.
To determine the best solution for your project, contact us for expert consultation and tailored product and roofing system recommendations.