Stud wall

[John Brown]

I need to build a stud wall, 4 X 2 and plasterboard. I'm hoping that I can find a plasterer who can give me a seamless transition from the existing wall into the new one, a straight line if you will.
Firstly, is this problematical? Will there be cracking over time, with seasonal movement or anything else?
Secondly, if it's not likely to be a problem, what depth of plaster should I allow for?
Thirdly, if it is indeed asking too much, are there standard ways of dealing with this?

 

[Rorschach]

It will crack, they always do whenever you have a change in material.

 

[gregmcateer]

I agree with R, that it will crack.
It can be reduced by they plasterer taping or 'scrimming' the join, which they would do normally.
Talk to your plasterer first and they'll tell you what thickness they will do.

 

[John Brown]

Thanks. I don't have a plasterer yet. But thanks anyway.

 

[Adam W.]

What's the existing wall made of ?

 

[John Brown]

What's the existing wall made of ?

It's. Skimmed plasterboard on studs.

 

[Adam W.]

That's good. Is it single skin of plasterboard or double ?

You can check this by taking off the light switch and having a peek inside. If it's double skin that's better, but even with single skin you can possibly make it work, but take a look first.

 

[John Brown]

That's good. Is it single skin of plasterboard or double ?

You can check this by taking off the light switch and having a peek inside. If it's double skin that's better, but even with single skin you can possibly make it work, but take a look first.

I'll check it out, and get back. Thanks.

 

[Lons]

It's. Skimmed plasterboard on studs.

So you're in effect extending the wall with the same construction and materials in which case any good plasterer will match up with minimal chance of cracking, ( I agree normally joins will crack if different). He'll want to trim back the existing skim and scrim tape it, any later fine cracking would be due to movement in your new wall and easily filled, easyfil works very well for that and easy to sand. The finished job depends largely on how good you construct your wall, I'd recommend using drywall screws not galv nails to fix the plasterboard btw and sink the heads flush with the surface, you can buy a cheap drill bit specifically for that purpose which prevents the screw going in too far..

I'm no plasterer but have done it many times without issues, I always allowed 3mm for a skim coat but as said your plasterer will tell you what he prefers.

 

[John Brown]

So you're in effect extending the wall with the same construction and materials in which case any good plasterer will match up with minimal chance of cracking, ( I agree normally joins will crack if different). He'll want to trim back the existing skim and scrim tape it, any later fine cracking would be due to movement in your new wall and easily filled, easyfil works very well for that and easy to sand. The finished job depends largely on how good you construct your wall, I'd recommend using drywall screws not galv nails to fix the plasterboard btw and sink the heads flush with the surface, you can buy a cheap drill bit specifically for that purpose which prevents the screw going in too far..

I'm no plasterer but have done it many times without issues, I always allowed 3mm for a skim coat but as said your plasterer will tell you what he prefers.

Thanks, Lons.

 

[Lons]

This type of bit John, you can get them from Screwfix, Toolstation and most of the sheds. Not essential but makes life easier.

 

[John Brown]

That's good. Is it single skin of plasterboard or double ?

You can check this by taking off the light switch and having a peek inside. If it's double skin that's better, but even with single skin you can possibly make it work, but take a look first.

The only light switch is on the other side of said wall, in the futility room. It's surface mounted, as luck would have it!
Definitely stud and plasterboard, though, I can find the studs by tapping. I have to move s light switch, which would otherwise be the wrong side of the new wall, so I guess I can check then.

 

[John Brown]

This type of bit John, you can get them from Screwfix, Toolstation and most of the sheds. Not essential but makes life easier.View attachment 111548

Thanks, I'll order one from Screwfix the next time I go there. What's it called?

 

[John Brown]

Ok. I've found it...

 

[Adam W.]

OK, but if you want to minimise the chance of it cracking you'll have to join the new board to the old stud along with the old board and scrim it with the self adhesive fibreglass tape.

You can either cut the old plasterboard down the centre of the stud, there may be two if your lucky, and screw both to it or attach one of those pressed steel studs along the old stud and screw into that. It won't shrink, obviously, as that's what you want to avoid at the join. Then build the rest of the stud wall in the usual way.

When it comes to skim coat, the new plaster won't create a feather edge and join with the old nicely, so readymixed joint filler is your friend at that joint as you can sand it smooth.

If you have double boards, then you can remove the top board at the stud before the join and lap the new ontop and scrim and plaster as before.

 

[John Brown]

OK, but if you want to minimise the chance of it cracking you'll have to join the new board to the old stud along with the old board and scrim it with the self adhesive fibreglass tape.

You can either cut the old plasterboard down the centre of the stud, there may be two if your lucky, and screw both to it or attach one of those pressed steel studs along the old stud and screw into that. It won't shrink, obviously, as that's what you want to avoid at the join. Then build the rest of the stud wall in the usual way.

When it comes to skim coat, the new plaster won't create a feather edge and join with the old nicely, so readymixed joint filler is your friend at that joint as you can sand it smooth.

If you have double boards, then you can remove the top board at the stud before the join and lap the new ontop and scrim and plaster as before.

That's all very useful, thanks.

 

[xy mosian]

If there is a metal trim to the existing wall corner, would there be any benefit in removing it?
xy

 

[Rorschach]

Ah sorry, I assumed brick wall joining to stud. As long as your join is as solid as possible then cracking shouldn't happen as the whole wall will move at the same rate.

 

[John Brown]

If there is a metal trim to the existing wall corner, would there be any benefit in removing it?
xy

I don't know yet, but I would suspect there is.

Just checked with magnet, yes, definitely metal corner trim. Good call, I would not have thought of that.
Looks like I need to investigate whether it's single or double boarded.

 

[Adam W.]

If there is a metal trim to the existing wall corner, would there be any benefit in removing it?
xy

Yes.