What colour plasterboard?

[unclebob1]

So i have a steal beam (supporting wall for the first and eventually loft) going through my new ground floor bathroom.

BC have specified the beam be boxed in fire rated plasterboard (pink). No problems.

Given that its in a bathroom, the walls all have moisture resistant plasterboard(green).

Should the boxing around the beam be layered in pink then green?
or does one of the two negate the need for the second?

I haven't asked bc this, but i assume from their view as long as pink is over the beam, the rest is between me and the builder?

 

[russellsmiler]

Youre right, Building control will only be concerned with the fire integrity of what you encase the beam,
12.5 mm pink (fireline board) x 1 sheet offers 30 mins fire integrity.
If you are keen on moisture resisting board to overlay again so that it suits the environment of your bathroom you may pursue if 2 x moisture board offers the same 30 mins integrity as 1 x pink, this way you would cut down on waste by using 1 product instead of 2

 

[endecotp]

There are plasterboards that claim multiple properties, e.g.

http://www.british-gypsum.com/products/gyproc-duraline-mr

"Gypsum plasterboard with fire and moisture resistant additives and a high density core for enhanced sound insulation and impact resistance performance."

 

[endecotp]

Or for just fire and moisture but not the acoustic and impact-resistance :

http://www.british-gypsum.com/products/gyproc-fireline-mr

 

[tomfe]

I do wonder how we all survived before we had all this different coloured pb around...

 

[^woody^]

If you leave the plug out in the bath, then the beam won't be getting wet so won't need moisture resistant board.

In fact, nor do the walls.

Normal plaster board would be ok on the beam

 

[garyo]

Is it true to say that normal 12.5 PB is rated to 30 minutes, so if a BCO has specified fireboard then you can satisfy that requirements with two layers of 12.5mm instead, if that's what you happen to have on site?

 

[unclebob1]

Thanks for the replies, it's actually a walk in shower area, and the shower happens to be in the part with the beam... The builders have boxed in pink and then put a second layer for the ceiling itself (there's an air gap) but this was for my own piece of mind...