St. Williams College

St. Williams College

The Problem: 

How to insulate a historic building with uneven rafters and existing ceilings below without raising the roof and without condensation risk.

Grade 1 listed

Nestled next to the imposing grandeur of York Minster is St William’s College, a jettied timber-framed Grade 1 Listed building with magnificent medieval halls within. Dating from 1465, it was originally home to the Chantry priests whose job it was to pray for the souls of their departed benefactors. St William’s has had many owners and different uses since then – even housing the Royal Printing Press during the Civil War!

Using an Insulating breather membrane when reroofing st Williams college york

Out with 1F and in with new breathable insulation

However, with only 1F felt and no insulation, the energy costs were prohibitive. Re roofing offered the chance to insulate, but it was essential to preserve as much of the fabric and structure of the original building as possible. With lath and plaster ceilings a vapour barrier could not be installed; the roof could not be raised and the rafters were extremely uneven.

Counter battening was not necessary

TLX Gold was used draped over the rafters, acting as both breather membrane and insulation, with 20mm - 50mm PIR board used between the rafters where they were sufficiently deep to accommodate it. There was no need to counter batten, and calculations indicated that there should be no condensation risk.

Finished off with award-winning lead work by Mark Winters, the building should head into its next 700 years warm and dry.TLX Gold draped St. Williams college

The Solution: 

BBA Approved TLX Gold, the 2-in-1 insulating breather membrane, provides a thermal upgrade in limited rafter depth without condensation risk.

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