Dumb Gyprock Questions

[Pete F]

G'day Guys, sorry but I have a few really stupid questions about gyprock I'm hoping someone could help me with.

The situation is that I have an existing stud wall which somebody removed the plaster from and replaced with wood t&g boards. I'm sure he thought it looked nice. The house is late 60's and the original cornice has remained in place (obviously attached to ceiling) so I need the gyprock to slide up between the studs and the cornice (hope that makes sense, there's a "groove" left at the top behind the cornice in other words).

Firstly, I wonder if gyprock is commonly available in various thicknesses? The studs seem rather uneven and until I get all the boards off it's difficult to see how thick it should be but maybe as much as 15mm? If it's too thin I would have to pack it forward to meet the cornice. [Edit: Since posting I can now see the plasterboard print on the reverse side says 3/8" recessed edge so I guess both sides were the same.]

Secondly, due to the uneven studs I presume the norm is to pack out anywhere fasteners will go? The only time I've done this before was on a new construction and the studs were pretty straight. I assume the blue glue will be fine for the rest of it?

Finally, should I nail or screw? The studwork is VERY hard timber and I thought screwing and pre-drilling may be easier.

As an aside, I've read warnings about not fastening close to the glue dobs and I was just wondering why that is? Just curious.

Thanks for the help.

Pete

[OBBob]

Hi Pete

Stadard Gyprock is 10mm thick, there are other thicknesses out there but I don't think you'd bother for this.

Studs are normally planed down or packed with masonite strips as required. Then the blue glue also takes up any gaps too.

[Gooner]

I am wondering about this too, as my studs are not completely vertical and I will be re-plastering the wall soon.

The studs are about 6-8 mm off vertical along the entire height of the room. I would not sand or plane this amount of material off the stud.

When I removed the original plaster it looks like the previous installer used the blue plasterboard adhesive to take up most of the discrepancy. (That stuff really sticks to the stud). I don't see any packing, so I am wondering how he got the plaster vertical to begin with using only adhesive.

[cflake]

Hey Pete,

As well as the normal 10mm, you can buy 13mm and 16mm (CSR has 13mm in stock, never bought 16mm so it could be a special order, they are both special order from bunnings). However, I would be more inclined to pull off the cornice and put a new piece in that lines up to some new 10mm you can hang. Cornice and the adhesive are pretty cheap.

Yes, you normally pack low studs or plane proud studs. You must 'flatten' the wall before you hang the board. Note that it doesn't need to be level or plumb, just flat. I use a aluminium straight edge and don't even look at a level, otherwise you would be there all day. Obviously if it's waaay out of plumb you may try to address it, but once it's finished and painted, how many visitors are going to ask to borrow a level to check your wall?

The blue glue is what's normally used. You're not supposed to fasten near glue because the nails can pop afterwards. As far as nails/screws, I'm no expert, but I usually use nails for walls and screws for ceiling, but I can't see a reason why you can't use screws for a wall.. Nails are probably faster though especially if you have to pre-drill. I'm doing a reno at the moment with hardwood studs and providing you hit it hard, the nail goes in fairly easily.

[Pete F]

Great, ok thanks guys, much appreciated. The reason I don't want to pull the cornice off is that, well firstly it will be a hell of a mess, just so much easier to slide a new piece of gyprock up there. Also, being an older house I'm not sure how I'd go getting that profile. Interestingly every single room in the house has a different profile (literally), go figure.

As I mentioned in my edit I can see the other side is 3/8" so I'll give 10mm a go and see what happens. I figured I can bog the gap (if any) between the gyprock and the cornice if it's not too much. If it is, I'll find some cunning way to make a "feature" of it (I never make mistakes, just creative "features". My place has a lot of interesting ones. Groan ).

Just to bludge some more good info. How long does the blue glue take to set up before I can start taping the joints/corners etc? With these smaller jobs it seems I am forever waiting for things to harden/dry before I can move on. It would be nice to have an idea when it should be done (then multiply it by 2 and double the cost).

Cheers,
Pete

[Gooner]

The reason I don't want to pull the cornice off is that, well firstly it will be a hell of a mess, just so much easier to slide a new piece of gyprock up there.

I pulled the cornices off. Wasn't hard....but was messy. I now have a feeling that it just may be easier to replace all the plasterboard on the ceiling, (its a small room), than try and get the gunk off where the old cornices were to put up new ones.

[Pete F]

I pulled the cornices off. Wasn't hard....but was messy. I now have a feeling that it just may be easier to replace all the plasterboard on the ceiling, (its a small room), than try and get the gunk off where the old cornices were to put up new ones.

Ha ha, I know how you feel. It's ironic how small jobs ...."I'll just do this" turn in to major renos. Would you believe this is part of laying a new floor (don't ask). It's the lounge room and if the Ministry of Finance arrived back home to find the ceiling on the floor instead of the nice American Oak she was expecting I'd be speaking about 2 octaves higher thereafter.

[DvdHntr]

It is better to redo the whole of the plastering than try and save some elements. I was going to try and save the cornice on my reno, but for the amount of effort involved it is more logical to do it all again.

[Pete F]

Ok, well that all seems to have gone according to plan. The only glitch is, having hung the last sheet late last night, this morning the bottom sheet is now 1-2 mm proud along the join between two of the studs. Just in the one place (right in the centre of the sheet). Because it's between the 2 studs I can't just put another nail in there. Is this sort of thing normal and the level difference is simply taken up as part of taping? It's still well below the level of the sheet (in within the recessed area) when I put a straight edge across the 2 sheets.