Todmorden Library Case Study

Todmorden Library Case Study

A building with history:

tlx gold todmorden library reroofNestled in the picturesque town of Todmorden is a library by the same name. Steeped in history, it was opened in its current state in 1897 and is now home to many historical artefacts. Therefore, when concerns were raised regarding the lack of insulation in the roof, it was imperative that the restoration was undertaken to the highest standard to preserve the longevity of the building and ensure it can be enjoyed for many years to come. However, like many old buildings of that time, the rafters are shallow, and a solution was required that would ensure thermal performance without having to compromise on space.

TLX Gold had the answers:

Our BBA Approved TLX Gold was the insulation of choice as it provides all the benefits of a multifoil insulation with the addition of an integrated breathable membrane; an excellent space saving solution as it does not require any additional membrane above. Furthermore, less additional insulation is required in-between the rafters to achieve the desired U value. Since the old rafters were shallow, the use of TLX Gold gave the peace of mind that valuable internal space could be saved and utilized to maintain head height within the building. It is the optimum thickness for a multifoil at 33mm, any thinner would see a loss of performance, whilst any thicker would give limited additional benefit.


The existing old felt was removed and replaced with TLX Gold, pulled taut and counter-battened over the top of the rafters. Installed in this way, it sags into the rafter space by a depth of 20mm, whilst approximately 10mm occupies the batten space above. An optimum 20mm of unventilated air was maintained beneath the shiny, breathable undersurface of TLX Gold to allow for the reflection of heat.

todmorden library reroofCutting:

Where one roll ends, one section can be adjoined to the next with the help of an overlap breathable membrane flap with integrated tape, situated on the short side of the roll end. However, at the edges of the roof, where there would otherwise be excess multifoil, Kretzer Finny scissors were used to cut the material back to the right size for the roof. To ensure air tightness and to maximize the overall thermal performance of the buildup, the layers of wadding were cut back by 50mm, leaving the breathable membrane top layer in place. In doing so, this creates a breathable membrane overlap which can be draped over the eaves carrier.

Sd Intelligence

The main concern was to limit the risk of condensation; architects on the job were aware that they needed a multifoil that would be responsive to variations in internal humidity due to the fluctuations in daily footfall. When they approached TLX Insulation, they were pleased to learn of TLX Gold’s Sd intelligence, meaning it can adjust its rate of breathability according to varying conditions. When humidity increases, the vapour permeability of the product increases and similarly, when humidity reduces, the vapour permeability of TLX Gold reduces also.  


Advantages TLX Gold multifoil insulation

  • TLX Gold is BBA approved and UKCA marked, a trusted multifoil which has been comprehensively tested to the highest standard
  • It is made in the UK
  • It can either be draped over the top of the rafters requiring no change in roof height or pulled taut and counter-battened over the rafters with a minimal change in roof height
  • Since TLX Gold is extremely breathable and water vapour can pass straight through TLX Gold, a vapour barrier isn’t necessary

If you are faced with an old building in need of a sympathetic restoration, TLX Gold will enable you to achieve the desired U value without needing to compromise on space. Our LABC Approved solutions guide is an excellent tool to direct you to the solution that is right for your project. Alternatively, our product scientists are on hand to help with build-up recommendations and bespoke U value calculations. Don’t hesitate to call them on 01204 674 730.

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