Loft Fire Regs - wire mesh under Rockwool required?

[Chas72]

Hi

Quick question. Does UK or England's household fire regulations require wire mesh (chicken wire) to cradle Rockwool that's fitted over a ceiling, when a new loft conversion is built?

We're in the process of agreeing final payment for a loft conversion we've recently had completed. The work's been signed off by a private BCO but does not include wire mesh under the ceiling Rockwool.


Thanks

 

[freddiemercurystwin]

I've never specified it, normally the new T&G floorboards and plasterboard will achieve the 30 mins resistance on its own. There could be an argument if your ceiling was lathe and plaster and it was in poor condition.

 

[^woody^]

It is not an absolute requirement, but can be a solution in certain instances

 

[stuartturbo]

Just doing a DIY loft conversion
22mm floor and http://www.stgbc.org.uk/ my local one also spec'd

170mm Rockwall between joists supported on wire mesh if ceiling is not plasterboard blah blah

 

[tony1851]

Inspectors here always ask for the wire mesh in loft conversions. The reasoning seems to be that the wire holds the fibreglass in position for a brief period should the ceiling drop out in a fire. In holding the fibreglass against the joists, it insulates them from the effects of the fire and so prolongs their life. If there was no wire, presumably the fibreglass could fall out with the ceiling and then expose the joists to the fire.

 

[jeds]

You don't say what your floor construction is? Building regs says nothing about chicken wire or wire mesh. What regs do say is that the floor should provide 30 minutes protection or 30 minutes 'modified' protection if it's an existing floor. That can be achieved in many ways. Chicken wire and insulation is just one of them. It comes from BRE208.

 

[ghostdog]

I'm also in the process of doing a loft conversion and the building inspector also mentioned chicken wire,but as I had already re boarded the existing ceilings with fire line plasterboard and skimmed them this would give the protection that is needed,check what plasterboard was used you should be able to see the writing on the back of it