Should I be screwing new plasterboard to old plasterboard?

[Adam1991]

Hi guys!

First post, i’m currently redoing the bathroom and need to board over the wall with where the shower is going to be so will have tiles on.

Heres my problem...1/4 of the old plasterboard is loose and has come off, so i’ve pulled some of the loose peices out and left the ‘solid’ sections in and fixed some 2”x1” to the brick in the gaps as fixing points for the new plasterboard.

I’ve come to screw part of the plasterboard into the 2”x1” and into the old plasterboard, firstly the screws arn’t taking to either plasterboard, i’m using drywall screws (30mm)...should I rawlplug them first and are the screws big enough?

Secondly the 2”x1” sits about 3mm to deep than the old plasterboard.

What would be your honestly decision on what to do here?

Se image attached of the old plasterboard and new 2”x1” fixed

 

[23vc]

The existing boards are dot and dabbed on, which may be easier for you to do and avoid the 2x1. If using the 2x1, you need more of it, ie including round the edges, and cut the edges more straight/square to allow this. No idea why 30mm drywall screws won’t go straight through a plasterboard into your battens, can you elaborate?
The dab/plaster on the copper pipe wants cleaning off, it’ll corrode it over time.
If the new board sits 3mm deeper than existing (if that’s what your saying) it’s not a big issue, just skim it with plaster or tile adhesive to level it

 

[Adam1991]

The plasterboard needs to sit directly against old plasterboard as theres no room for dot and dab due to the shower valves needing to be protruding out the plasterboard to allow the valve plate to sit on top. Hence the reason i’ll be screwing them. I was more concerned about the 30mm screws going through the new plasterboard, then the old plasterboard.
They dont seem be holding, just coming straight back out, should i pilot the holes first or use rawlplugs?

Thanks for that! Didnt know about that on the pipe!

Not exactly, the battens sit 3mm deeper than the old plasterboard so when i put the new plasterboard on top of the old one and try to get it to sit flush, where i’m screwing straight through into the battens its bending the boards slightly and causing a sloped wall

 

[23vc]

Are you trying to over board the whole lot then? If so, you can’t screw it, as there’s no other battens other than your little bits shown. Need to dab it/no more nails it if the old boards are staying

So yeah, understand your original question now (I think), you can’t just screw to plasterboard, nowhere near solid enough and screw will just pull out

 

[Adam1991]

Ahh right! Thats where i’m messing up then! Thats exactly what i was planning on doing. ‍

The plumber recommended I screw it on...i guess thats why he’s a plumber and not a plasterer

Thanks for the advice man, so heres my next question...

What would you do, rip the old plasterboard and chisel the dab off the brick, fix wooden battens to the brick and put the plasterboard up that way. Or no more nails the the plasterboard to the old ones and add some wooden battens round the edges to help secure it?

 

[CJRatch]

The best job would be to remove the lot and reboard. Second best I'd cut some circles say 6" x 6" out your old board exposing the block below. Try to avoid the current dabs, give it a tap before you cut. These circles now allow a good fixing onto the block work below for your new boards using drywall adhesive.

Dab a large amount onto the exposed block so it's much deeper than the old boards depth as to give your new board a good fixing. I'd also butter the old boards up a little then press your new boards firmly onto this.

Put some dabs around your battens to for belt and braces but as above avoid the pipes.

 

[bobasd]

that lots wrong from the get go.

best as above to strip the lot back to blockwork.
you dont use plasterboard in wet areas - you use backer board or solid render backing on any wet wall.
the plumbing doesnt look to clever either. have you tested an operated the valve an pipework soundness under wet pressure?
hopfuly the valve is set at the right depth for the finished tile surface?
what make valve is that?
is proposed a shower over a bath or a shower compartment?

 

[Adam1991]

Ahh right bobasd, i wish i’d known that before buying all the plasterboard. I was told as long as i use a waterproof grout and sealant it’d be ok to tile onto plasterboard?

Yeah the plumbers tested it and all works fine. We had an old electric shower in so the pipe you see coming from the ceiling is the cold feed that was originally there. God knows why its coming from the ceiling and not below.

Yeah i’ve tested it with board, tiles and the valve faceplate on so its a good fit. Its going to be a walk in shower, so the full length of that wall

 

[23vc]

Agree re. Taking all the old board off. Agree that cement board is better, but normal plasterboard if tanked properly with waterproofer kit should also be fine, I’ve done many like that and never had any issues. Once stripped back you can either batten it or Dab it (assuming your using plasterboard). If you’re using cement board, batten it

 

[Adam1991]

Great thanks for you help! I’ve just ripped the old wall out now...can i just leave the old dabbing on the wall and use it as a bit of support along the with battens or should i chip it all off?

 

[23vc]

Take them all off, then work out how to get your new boards at the correct depth for the shower valve. Which could be either dabbing or battening.

 

[Adam1991]

Ok, cheers for your help 23vc i’ll get to work on that!