Car Builders Water Proof Carpet Underlay is a single layer, closed cell foam, meaning it does not hold water. It also works great as a thermal and acoustic insulation barrier.

It is suitable for 4x4's, convertibles and industrial vehicles, which get constantly exposed to wet environments.

Car Builders Water Proof Carpet Underlay will not stay damp, smell, rot or attract mould like pre-dated cotton mill scrap, traditionally used under carpets.

It comes with a peel and stick backing and is easy to cut and install. It is also effective as a thermal barrier to reduce heat transfer from the exterior of your vehicle.  The material will reduce radiant heat by up to 20°C, and can be the difference between discomfort and pleasure.



  • Light Weight
  • Easy installation - just peel off the release liner and adhere to surface.
  • Cuts with scissor and knife
  • Reduces heat transfer
  • Does not rot or deteriorate


  • Under carpets
  • Roof skins
  • Inside cavities
  • 1/4 panels
  • Doors
  • Firewalls


Each box comes with 1 sheet inside, each sheet is 1800mm x 950mm resulting in 1.71sq/m.



Waterproof Carpet Underlay FAQ

What thickness carpet underlay should I use?

Carpet underlay thicknesses range between 4-12mm. This range allows you to insulate effectively and fit it under tighter areas such as the transmission tunnel.




Sheet size:
1800 x 950mm 


Closed cell foam

Adhesive Resistance Temperature Range:
-40°C to +110°C (long term) +135°C (short term)

Flame retardant:
Yes, B2

Shipping Weight 2.0000kg

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