Surface preparation: Concrete surfaces should be free from cavities and projecting nibs. All surfaces shall be dry and free from contamination, frost & surface laitance.
Priming: For applications on concrete, coat the substrate with RHEOPRIME D41 primer at the rate of 4 – 5 m2/litre. Allow this coating to dry thoroughly. In time of high humidity, we recommend it should be left overnight.
Application: The RHEOSEAL 4S & 5S membranes should first be unrolled and positioned correctly. Each roll should overlap the adjacent roll by 100 mm. Once the roll has been positioned correctly, the membrane should be rolled up again, taking care not to change its orientation. Using left to right movements, heat the lower surface of the membrane with a propane gas torch. This will cause slight surface melting and the molten bitumen will adhere to the surface. Then torch on the side overlap to the recommended size of 100 mm. Continue the above method for consecutive rolls remembering end-laps must be minimum 150 mm. Heat both the overlaps and use round tipped trowel to seal the overlap. Adequate heat is confirmed when a uniform flow of melted bitumen compound flows evenly in a bead that oozes from the applied membrane’s edges. Excess compound should be pressed into the seam using a heated trowel. Any un-bonded areas must be lifted and re-torched. Inspection of lap joints must be carried out to ensure total adhesion.
Protection: RHEOSEAL 4S & 5S should be protected from getting damaged due to the ongoing site activities and during backfilling. Membranes laid on horizontal surfaces can be protected either by a cement sand screed (50mm thick) or by asphaltic protection board RHEOBOARD. On vertical surfaces the membrane has to be protected with RHEOBOARD. RHEOBOARD can be fixed on the membrane by torching the underside of the board.