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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Building Questions >> Wiring plasterboard to beam https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1278966555 Message started by JohnH on Jul 12^th, 2010, 9:29pm

Title: Wiring plasterboard to beam
Post by JohnH on Jul 12^th, 2010, 9:29pm

Hi folks [smiley=wave.gif]

As above really, I have to box in a steel beam, the spec says:

'All beams ... covered with 2 no. sheets of 12mm plasterboard wired at 100mm centres'

I've come across this phrasing several times while searching Google, but can't find any pic or description. Do I have to drill the beam??

I asked the builder I got to put the beam in, he wasn't sure and said he'd fix to noggins knocked between the beam flanges. I believe the 2 sheets of plasterboard and wiring are for fire regs, so using wooden noggins seems counter-productive.

So how do I wire it?

Title: Re: Wiring plasterboard to beam
Post by CWatters on Jul 13^th, 2010, 9:44am

Hopefully someone can give you a better answer but..

I believe fixing to timber is acceptable. The two layers of plasterboard is to protect the steel beam from fire and would also protect the wood. As I understand it steel is more vunerable than a wood beam because the strength of steel is more dependant on temperature.

Perhaps check with your BCO if he's happy with you fixing to timber?

Aside: I've read that the joints in the first layer of plasterboard should be filled and staggered with those on outer layer?

Title: Re: Wiring plasterboard to beam
Post by greg on Aug 6^th, 2010, 10:47pm

I believe that when boxing in steels now, the timber must be "mechanically" fixed to the steel, you can't just wedge noggins in the flange any longer

Title: Re: Wiring plasterboard to beam
Post by JerryD on Aug 12^th, 2010, 11:33pm

We always Hilti timber to the steel inside the web and then p/board two layers over the top (with staggered joints of course) and a metal bead on all external edges.