Fireshield® Breather Membrane

Fireshield Breather Membrane


Fireshield Breather Membrane is a vapour permeable membrane for use on walls behind cladding. The unique coating eliminates fire spread rather than just resisting it. It is installed and fixed to the substrate in the same manner as standard breather membranes using mechanical fixings.

Key Features

  • Fire proof surface - unique composition actively reacts to prevent fire taking hold.
  • Vapour permeable walling underlay for use either directly onto sheathing or insulation.
  • Class B, s1-d0 but performs differently to other similar class products.
  • Complies with BS5250, BS4016 & NHBC requirements for vapour permeable walling underlays.
  • Ideal for use in rainscreen / façade construction.
  • Suitable for applications over 18m high.
  • LABC & LABSS Certified.
Fireshield Breather Membrane
Fire Rated Breather Membrane Fireshield

0 Seconds

Fireshield (right) and a competing fire retardant membrane (left) are fixed to a 10mm OSB panel with staples. A butane torch is positioned approx. 10cm from the face of the membranes at a 45 degree angle. Two cameras capture the view from front and back.

Fire Rated Breather Membrane Fireshield

After 1 second

Immediately after the butane torch fires, the competing membrane begins to melt and shrink away from the heat source, exposing the OSB. There is no physical change to Fireshield.

Fire Rated Breather Membrane Fireshield

After 1 minute

On the left side, the competing membrane retreats further from the flame and the OSB begins to burn. On the right side, the flame has caused Fireshield’s intumescent surface to react and ‘puff up’ which protects the membrane and the OSB.

Fire Rated Breather Membrane Fireshield

After 6 minutes, 30 seconds

The reverse-side of the OSB on the left begins to discolour and smoke as the flame penetrates the OSB under the competing membrane. Fireshield’s fire-proof surface continues to intumesce in response to the fire. No discolouration or smoke on the reverse-side of the OSB on the right is observed.

Fireshield Breather Membrane

After 11 minutes, 35 seconds

The OSB panel under the competing membrane on the left is breached by fire, and flames appear on the reverseside. Fireshield continues to puff-up. No discolouration or smoke on the reverse-side of the OSB on the right is observed.

After 20 minutes

The competing membrane exposed the OSB directly to fire from the outset and, as a result, the OSB burned completely through before the test was over. The torch over Fireshield was left on for a full 20 minutes. Even though the membrane itself did not catch fire during that time, the front-side of the OSB panel only received minor scorch marks and did not ignite.