Plasterboard wall for under the stairs cupboard

tallac

I have a U shaped winder staircase and the builder has created an under the stair storage cupboard in the dead space underneath it. The wall of the cupboard is just a board of plasterboard that's been painted on the side that is visible. This doesn't seem very robust but to make matters worse, it also has a double mains socket in it too, the back box is obviously sticking out of the back of the plasterboard (which is hidden as it's inside the cupboard).

My question is, how robust will this plasterboard be in the long run? Is it normal for it just to be plasterboard or should it be supported by something else behind it?

FreeBear

Plasterboard is usually fixed to timber studwork typically spaced ~400mm apart. It is also possible to get a PB sandwich with a foam or honeycomb core which doesn't need any studwork behind it.

A plastic back box designed for use with a PB wall is OK - Personally, I dislike them when used with sockets, particularly a double. Pushing/pulling plugs could eventually see the plasterboard crumbling at the edges..

Jeepers_Creepers

Plasterboard walls are just that - sheets of p'board screwed onto vertical studs and the odd horizontal noggin.

Where it can be a problem is when the gap between the studs is too large. 600mm spacings, for example, would definitely require the thicker - 12.5mm - sheets and also horizontal noggins.

Does it feel 'weak'? Ie - when you thump it, does it flex any more than any other wall (bearing in mind that your other walls will also have around 3mm of plaster skim on it)?

J_B

Are you saying it's just a single sheet of p/b with no backing?

Hmm

tallac

Sorry for the delay, I spoke to the builder and he has reassured me that the plaster board is very strong even with the socket that is fitted directly to it. Here is a picture (the wiring is not live yet so that still needs to be made safer):

tallac

View from the front side:

SaverRate

Looks like its fixed back to studs so its fine. Electrical wiring could be pinned against the studs to clean it up and the grey sleeving should ideally enter the back box but was that in his scope of works? 

Jeepers_Creepers

I have to confess that my understairs cupboard - and under-eaves storage - is the same. Why? 'Cos I'm lazy, and made the judgement that the extra effort for what is a cosmetic issue wasn't worth it.

That wall is just as strong as all your other p'board walls, Tallac.

Perhaps a horizontal noggin along where the boards join would have been nice, but hey.

FreeBear

Jeepers_Creepers said: Perhaps a horizontal noggin along where the boards join would have been nice, but hey.

I'd also put a small nogging across the top of the back box - To save screwing the plasterboard to the timber, a generous dollop of grab adhesive would hold it together. The cabling also needs to be clipped to the studwork or in conduit if the inside of the cupboard isn't being boarded out.

couriervanman

Shouldn't there be plasterboard on the back as well

Jeepers_Creepers

couriervanman said:

Shouldn't there be plasterboard on the back as well

Only if you want.