Bitumen Roofing Felt

Bitumen roofing felt which are impregnated with bituminous impregnating agents. These roofing felts are build up of multiple layers of high performance felts and mastic asphalt over an insulated timber or concrete flat roof deck.

Felt (Hessian) is a high quality bituminous waterproofing membrane with Hessianascentrecore.lt conforms to IS: 1332:1993 type 3 Grade 1. 
It is produced by saturating the centre core of hessian with straight grade bitumen and then coating it further on both sides with industrial grade oxidised Bitumen. Mica is then sprinkled on the bitumen on both sides to protect it from Ultra Violet rays and also to prevent adhesion.

This has a fibreglass centre core instead of Hessian. Straight grade and oxidised bitumen are used for impregnating and saturating the centre core of the fibreglass. This conforms to IS 7193/1994 Cr. Both The Great Bengal Felt Hessian and FG are tested and tried waterproofing membranes and offer total impermeability to water. Both are easy to apply, easy to repair and maintain.

Both are used for basement and roof waterproofing and many different types of surfacing such as

• Concrete
 
• Asbestos / GI sheets
• Timber
 
• Shell / Folded plates
• They are ideal for waterproofing of silos, grain godown, warehouses, buses etc.

• The surface should be thoroughly cleaned with wire brush.
• Repair cracks, if any.
• Apply Bengal primer on the surface.
• Let the primer dry up. Then apply a coat of hot bitumen.
• Rolls of The Great Bengal Hessian Felt should be laid over the hot bitumen and pressed properly to avoid air gaps.
• A minimum overlap of 100mm and 75mm should be made at the ends and sides of The Great Bengal Felt respectively.
• For double layer treatment, the joints between the two layers should be staggered.
• A cement concrete fillet should be prepared at the junction of the roof and the parapet wall. The Great Bengal Felt should be fixed in groove (50 mm x 50 mm) made in the parapet wall. The groove should then be filled with cement mortar (1:4).
• The top coat of stone grit or gravel (6mm size) should be laid by spreading hot bitumen and then laying the gravel over the bitumen.