2. Bitumen
Bitumen (asphalt or coal-tar) is a mixed substance which is made up of
organic liquids that are highly sticky, viscous, and waterproof.
It is produced by removing the lighter factors such as liquid petroleum gas,
petrol and diesel from heavy crude oil during the refining process.
Water Proofing
Adhesive
Hardness
Viscosity
Properties Of Bitumen
3. Bitumen Felts
‘Felt’ is an unwoven fabric made by matting fibers under pressure. Typical
use of Bitumen felts are as an underlay beneath other building materials,
particularly roofing and siding materials.
It helps protect the roof deck from rain until roofing is installed and
provides an extra weather barrier.
4. Manufacturing Process
Roofing felt is manufactured in roll format.
Rolls of base felt are pulled on rollers through large tanks
of bitumen mixes until they are saturated with the tar-like
bitumen mixture.
Modified bitumen is mixed with filler components such
as limestone, sand, or polymers such as atactic
polypropylene (APP) that gives rigidity and tear
resistance or styrene-butadiene styrene (SBS).
Styrene-butadiene styrene (SBS) is a rubber additive that
gives more elastic benefits.
5. Types of Bitumen Felts
Base Fabrics: Fiber base felt should consist of suitable blend of
vegetable and/or animal fiber and weight of ash after incineration
should not exceed 10% by weight of original. The Other type is
Hessian base fabric .
Bituminous saturant: penetration is not less than 80 at 25 oC.
Weight in these is not less than 110% and 60% of minimum
weight of fiber base and hessian base .
Bituminous Coatant: The bituminous coatant used for Types 2 and
3 felts shall consist of bitumen conforming to IS 702: 1988,
softening point is not less than 105oC when tested by ring and
ball method and penetration is not less than 7.
6. Prices in Market
Bitumen Felt roll
Thickness:- 3-4 mm
Brand :-Swastik Tar
Cost:- Rs 83/ Sq. m
Bitumen Plastic Felt roll/ Tarsheet
Thickness:- 4 mm
Brand :-Swastik Tar
Cost:- Rs 800/ Roll
Dimensions:- 1m x 20m
Hessian Based Bitumen Felt
Thickness:- 4-6mm
Brand :-Kirtan Internationals
Dimensions:- 1m x 20m
Cost:- Rs 1,482/ Roll
