The Self Build Self Help Site Closing the Cavity

A one-stop shop of information for people interested in self build - whether self building a complete home or undertaking an extension, renovation or modification.

Closing the Cavity
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The cavity needs to be closed at wall plate level in order to reduce the risk of any fire propagating to the roof structure. It does this by stopping any flames directly but also by reducing air currents that will fan flames.






Traditionally this has been done by fixing roofing slates across the top of the cavity. This task isn't so bad at the top of the walls but sticking the slates over the cavity up the gable walls is trickier - making them stick on the walls and not working loose at any time. The gable ladder teeth do help to keep them in place.

This is rather time consuming, so consider the option of a commercially produced cavity closer - costs of labour versus materials - see the final photo.

using slates to close the cavity

using slates to close the cavity

using slates to close the cavity

using slates to close the cavity











The photo to the right shows ROCKWOOL Cavity Barriers which contain a fire suppressant material enclosed in a polythene sleeve. They are designed to be compressed into the cavity and hence just hold themselves in.

Be specific when you order them, otherwise you are likely to be supplied with the rigid cavity closers that are fitted into the cavities around doors and windows.

using ROCKwool to close the cavity

The cavity needs to be closed at wall plate level in order to reduce the risk of any fire propagating to the roof strucutre. It does this by stopping any flames directly but also by reducing air currents that will fan flames.

Traditionally this has been done by fixing roofing slates across the top of the cavity. This task isn't so bad at the top of the walls but sticking the slates over the cavity up the gable walls is trickier - making them stick on the walls and not working loose at any time. The gable ladder teeth do help to keep them in place.

This is rather time consuming, so consider the option of a commercially produced cavity closer - costs of labour versus materials.

using slates to close the cavity

using slates to close the cavity

using slates to close the cavity

using slates to close the cavity

The photo below shows ROCKWOOL Cavity Barriers which contain a fire suppressant material enclosed in a polythene sleeve. They are designed to be compressed into the cavity and hence just hold themselves in.

Be specific when you order them, otherwise you are likely to be supplied with the rigid cavity closers that are fitted into the cavities around doors and windows.

using ROCKwool to close the cavity

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