Woven Fibre Glass


Shell FG4 is an open mesh fabric woven specifically for the reinforcement of asphalt, bitumen mastics and waterproofing emulsions.

Shell Fg4 has great strength, and does not romove volatile solvent oils from the medium that it is reinforcing. It is unaffected by micro-organisms, by weather or by soil exposure, and its high tensile strength provides greatly increased resistance to cracking and ensures considerably longer life for the protective coating.


Used with asphalt and bitumen mastics and emulsions in the waterproofing of new and old roofs. It reinforces protective coatings used in building cinstruction,foundations and subway walls

Shells FG4 can be applied over the surface of a roof, within gutters, and in the angle of all upstands such as parapet walls.

To preserve from corrosion,pipes for use above or below ground are often wrapped with narrow strips of woven glass fabric incorporated as areinforcement for the prtective coating.


Clean off all moss, dirt and loose material.

Prime the surface to be reinforced with an appropriate primer. Allow to dry.


Apply a layer of the chosen protective coating by brush or spray over the clean surface of the structure being treated surface and thoroughly unrolled over the treated surface and thoroughly embedded with a brush or squeegee. Provide a minimum of 75mm and 100mm end and side lapping respectively. It is important that the woven glass fabric is adequately smoothened across the surface to avoid any wrinkling effect. Pipes are usually spirally wrapped by hand or machine with adequate overlap, using a narrow strip of fabric which has been slit to the required width.


Flammability: Non-flammable.

Skin contact: Does not have any effect on sensitive skin.


1 metre width by 100 metre length roll.


Indefinite under good storage conditions.


The product must be kept sealed and stored under cover.


  • Roll size: 1m × 100m length
  • Weave: Plain
  • Thickness: 0.13mm ± 0.025
  • Finished weight: 64.5g/m2 ± 0.5%
  • Thread Count (per 25mm)
    • Yarns Warp: 20 ± 4
    • Yarns Weft: 10 ± 4
  • Tensile Strength: ASTM D579-90
    • Warp: 17 N/mm2
    • Weft: 20 N/mm2
  • Dry Pick Up (%):23-26


While every effort is made to ensure that the contents of this publication are current when going to press, customers are advised that products, techniques and codes of practice are under constant review and liable to change without notice.

Up to date information is available from the Sales Office on request. Responsibility cannot be accepted for the application of products and no claims can be considered where the manufacturers’ instructions have not been followed.

All products are sold subject to our standard conditions of sale, available on request.