Torprufe FS Primer (RC253) is a single pack, mild odour, low aromatic hydrocarbon solvent based acrylic primer used as a stabilising and bonding primer on new and weathered smooth bitumen based felts prior to application of Tor water based roof coatings (Torprufe CRC, Elastaseal WB etc). May also be suitable (subject to test) over synthetic carrier membranes. Also as a substrate bonding primer for installation of TorVap VCL / CM in Tor built-up warm roof systems.

Preparation

Before applying material, ensure all surfaces are prepared to a clean, sound, dry condition, free from grease, oil and other contamination.

New Bitumen Felts
Due to the wide range of felts in the marketplace, this procedural guide relates to traditional bitumen-based felts, while requirements for other grades (subject to suitability for coating) may vary. Thoroughly scrub down with a 10-15% aqueous solution of Torstrip WDA10 (SS420) to remove light oils, loose sand particles etc. Allow to soak in for at least 10 minutes then remove all residues by high pressure water jetting or thorough water scrubbing and rinsing.

Weathered bitumen felts (slight crazed, well bonded)
Treat all biological growth with Torkill W Fungicidal Solution (DM405). Leave overnight to activate then remove all residues.

Synthetic Carrier Membranes
Installation of Tor Built-up Warm Roof Systems
Ensure surfaces are smooth and level, free from dust, protruding materials and other debris. On existing aged asphalt, ensure surfaces have been fully prepared to remove all weakly bonded materials chippings (if present) and all damaged areas have been properly made good.

Limitations

• This product is not a general purpose roofing primer and its use should be restricted to substrates and roof waterproofing systems for which it was designed. Test applications
• must be performed to determine adhesion and suitability on substrates other than bitumen felts.
• Do not overcoat sooner than the minimum times stated on the products Technical Data Sheet on bitumen felts. Suitable overcoating times on other membranes will vary and require verification.