Stainless steel chimney liner installation in Plymouth

What a UL 1777 listing means for a liner

UL 1777 is the standard chimney lining systems are listed to, and the residential code accepts listed and labeled systems that comply with it. The listing covers a system installed as its instructions describe, with the parts named there, not a length of pipe on its own.

That is why we install the liner, top plate, cap, base fitting and any insulation as one assembly instead of mixing components from different makers. Your paperwork records the product, so a later sweep, inspector or buyer can see exactly what was installed and check it against the same instructions we followed.

Signs of condensation in a flue

Staining, dampness or deposits running down the flue can signal flue gases cooling too much before they leave. Oversized flues and chimneys on outside walls can both contribute.

Liner sizing and insulation address that directly. We look at the appliance, the flue size and where the chimney sits before recommending a fix. Moisture from rain entering an uncapped flue can look similar, so we rule that out before blaming condensation.

Lowering the liner without damage

A flexible liner is guided down the chimney, sometimes with a pulling cone and rope from below while it is fed from above. Forcing it past a tight spot can tear insulation or crush the liner.

We take it slowly and stop if the liner binds, rather than pushing through a restriction nobody expected. If the route has to be reconsidered, you hear about it before anything is cut, along with what the change means for the scope.

Questions worth asking before you approve relining

A sound relining proposal should answer each of these clearly. If one of them gets a vague answer, ask again, since each one affects how the liner performs or what the job includes.

• What finding makes the current lining unsuitable?
• Which listed product is proposed, and at what size?
• Is insulation required, or only recommended?
• What preparation happens before the liner goes in?
• Which old parts stay, and which come out?
• Which separate repairs, if any, are recommended?