No condensation risk?
Although one of the main reasons for using TLX Gold is because its breathability ensures that there is no condensation risk, in fact it’s even smarter than this! The shiny gold low emissivity undersurface comes from natural materials, and it is actually able to alter its rate of water vapour transport according to the humidity conditions.
Grade 1 listed? No problem
TLX Gold was chosen for use at Crossness Pumping Station, a Grade 1 Listed industrial building in London, because it offered a fully 
breathable boarded roof solution, and the self-adjusting vapour permeability has proved an added bonus. The Pumping Station was built in response to the ËœGreat Stink’ of 1858, to control the sewage entering the Thames.
Working with humidity changes
It has a huge James Watt beam engine, and internally it features spectacular ornamental Victorian cast ironwork. It is open to visitors, so there can be dramatic changes in humidity. Not only depending on the season, but on the number of visitors. So when the place is busy on Bank Holidays, with a peak in internal humidity conditions, the insulation can respond by allowing more water vapour out. No reason for the visitors to have any hint of the cold, dank conditions that must have prevailed when the station was in use!
How does it work?
So how does TLX Gold achieve this humidity-responsive behaviour? An active transport process operates, with water molecules passing directly along the chains of polymer molecules, from one to another at a rate that depends on the humidity. Contrast this with perforated foils: when a water molecule diffuses across a hole, the Ëœrandom walk’ path taken is akin to a blindfolded drunken man eventually finding his way out through a doorway. Not very efficient!
The Problem:
- How to ensure full breathability that is also responsive to changing internal humidity condition
The Solution:
- Able to change its vapour permeability in response to changing humidity
- Integral high quality breather membrane
- Fully breathable “ 0.5 MNs/g “ even the low emissivity reflective underside is based on natural breathable materials
- No increase in roof height required
