Question 1

Does the liner stop ground gases such as radon and methane?

Accepted Answer

The liner is a solid GRP laminate and resists the passage of gas, but it is not a certified gas barrier to BS 8485 and carries no gas transmission rating. Where there is a ground gas risk such as radon or methane, this must be specified and addressed separately as its own certified gas membrane system. We do not supply the liner as ground gas protection.

Question 2

Once the liner is installed, can a fault be found or repaired?

Accepted Answer

Once the build is complete, the liner sits within a cavity formed between the outer pit wall and the inner lift shaft wall, with the screed sealing its base. At that point it cannot be inspected or repaired without breaking back into the structure. This is no different to a cementitious coating, a bitumen membrane or a poured concrete wall, all of which are equally sealed in once the surrounding structure is complete.

Question 3

How does the liner cope with ground or structural movement?

Accepted Answer

The liner flexes slightly under load rather than cracking, so it continues to perform after the kind of small movement that is normal in any building.

Question 4

How long does the liner last?

Accepted Answer

We have been manufacturing GRP lift pit liners for over 30 years and have never had a failure or leak reported on any of them.

Question 5

Does the liner need any maintenance once installed?

Accepted Answer

No. Once installed, the liner needs no maintenance.

Component	Specification
Reinforcement	Chopped strand mat and woven glass cloth
Resin	Lloyd's Register approved polyester resin
Gelcoat	DNV (Det Norske Veritas) approved isophthalic gelcoat

Length (mm)	Width (mm)	Depth (mm)
1980	1980	1220
1980	1980	1220
2900	1980	930