TLX Gold Insulating Breathable Membrane


First there was bitumen felt - or nothing!

Roofing underlays and insulation have evolved considerably in recent decades. Before the nineties the rafters over a room-in-the-roof would have had a bitumen felt on top and possibly a small amount of glass wool  - or none at all. And prior to that, no insulation and possibly even no felt.

Then came breathable Membranes

Then breather membranes were introduced – underlays going over the rafters that were waterproof, yet which still let water vapour to escape through them. The noughties arrived and with it multifoils - lightweight air-filled layers with shiny surfaces that reflected back heat across air gaps created adjacent to them. The snag with these is that they were invariably vapour barriers – and vapour barriers belong on the inside of a wall or roof insulation buildup up to prevent water vapour escaping to the cold side where it could condense. If they are used on the cold side under the breather membrane, they are trapping moisture at the very place they should be letting it through.

A Breather membrane with Insulation?

So how to combine a multifoil  - with its airy structure and heat reflecting surfaces - with a breather membrane which has to be completely breathable?

The answer: TLX Gold. A top quality breather membrane is combined with an airy wadding (which also has internal reflective layers) yet the whole structure is breathable. The really clever part is the shiny underside – which  - although it is continuous and looks as though it shouldn’t let any moisture through at all – is able to let water vapour pass because of its patented structure.

TLX Gold insulating breathable membrane install

The breather membrane on the top is TLX UV25 – TLX’s high tensile breather membrane. The core consists of layers of polyester wadding plus some reflective layers, and the underside is the shiny gold layer that reflects the heat back across the air gap that is created below it.

But from design concept to product you need to think about how the product is installed and actually performs in use, and in this respect a lot of thought goes into designing something that is fit for purpose. TLX Gold has ultrasonically welded seams so it’s not going to fall apart on a windy roof, and an additional 150mm membrane   extension all down one long edge that laps onto the next roll down, with an integral adhesive tape to locate onto the roll below. And with a BBA Certificate resulting from exhaustive testing where the test numbers can’t be fudged, you know that it will perform as specified.

View our LABC Gold approved solutions HERE

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