Fireshield® is a vapour permeable walling underlay with an intumescent coated surface. Fireshield is suitable for all walling applications including those in multiple storey buildings. The intumescent coating helps protect the substrate by reducing the risk of fire taking hold and significantly reduces the formation of droplets and smoke. It is installed and fixed to the substrate in the same manner as standard breather membranes using mechanical fixings.

  • The unique intumescent coating helps protect the substrate
  • 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
Fireshield® product image
BBA Certificate
BBA Certificate
NBS - Fireshield
NBS - Fireshield

Product Information

Fireshield® Comparison Test

0 seconds

Fireshield - Comparison Test - 1

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.

After 1 second

Fireshield - Comparison Test - 2

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.

After 1 minute

Fireshield - Comparison Test - 3

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

After 6 minutes, 30 seconds

Fireshield - Comparison Test - 4

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.

After 11 minutes, 35 seconds

Fireshield - Comparison Test - 5

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

Fireshield - Comparison Test - 6

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.