Envirograf Timber Frame Cavity Barrier Range

Availability: In Stock


These lightweight, adhesive-backed cavity barriers are ideal for use in timber-framed buildings, party walls and cavity surfaces with with a rendered finish.

CV Strip Cavity Barriers A flexible, PVC and foil-clad intumescent strip with self-adhesive backing to adhere it to walls. High expansion intumescent will lock against the external side of the internal wall in a fire, giving full protection without affecting the outer wall. These are strips for ventilated cavities.

They come in 30mm and 75mm widths, for cavities voids between 30mm and 120mm large. Refer to the table below to ensure you are ordering the correct size.

FB/TS Cavity Barriers are made from intumescent sponge which is encased in UPVC foil and red PVC coating. This seals the barrier against moisture. It has self-adhesive backing which facilitates installation. It expands at medium pressure in a fire, which seals it off from fire and smoke.

These come in two sizes: 50mm x 50mm and 40mm x 50mm.

Envirograf Timber Frame Cavity Barrier Range

Envirograf produce two main cavity barriers for ventilated timber frame cavities: the CV Strip range and the FB/TS sponge strips.

Both barrier ranges can provide up to 2 hours protection, depending on the scenario.

The CV Barriers have been fire tested in accordance with BS476 parts 20,22 and BS EN 1363-1 (1999).

The FB/TS Barriers have been fire tested in accordance with BS EN 1363-1 (1999).


The CV Strips have a small profile so are ideal for installation into modular buildings where space is limited.

FB/TS barriers are used on load-bearing party floors and walls as they are more robust.

Both come with self-adhesive strip for easy installation. We recommend also using mechanical fixings spaced 300mm apart to secure the barriers into place.

Large CV barriers come with fixing brackets which are needed for their installation. The smaller ones do not require these brackets.


Order References:

CV Cavity Barrier Strip

Ref                   Width         Thickness           gap size protection

CV30/4           30mm            4mm                    30/45mm

CV30/6           30mm            6mm                    50/60mm

CV30/8           30mm            8mm                    60/70mm

CV30/10 v      30mm          10mm                   80/90mm

CV30/12 v      30mm         12mm                 95mm/105mm

CV30/15 v      30mm          15mm               100/120mm

CV75/4            30mm          4mm                   30/50mm

CV75/10 v       75mm          10mm                 80/100mm

Available in 1 metre and 2 metre lengths.

V – with Brackets

FB/TS Cavity Barrier

FB/TS             Timber frame with brick/timber facing

50mm sponge & intumescent for party walls and floors

All 1m long.


Other cavity barriers are available to view here.


The information displayed about the products on this website is to be used for guidance ONLY. We advise that all customers contact our technical department to obtain a free no obligation specification and quotation before purchasing goods directly from the website.

Please be aware that any negligence caused by failure to obtain the relevant advice, or availment of our specification and estimation service, will absolve International Passive Fire Ltd from any liability should Passive Fire Protection Products prepared, or used, by the purchaser, or any other parties, result in damage to property or human life, or for any monetary costs incurred due to incorrect usage.


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Fire Rating


4mm, 6mm, 8mm, 10mm, 12mm, 15mm, 50mm, 40mm




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