Maximum gap between plasterboard joints?

GreeBo

Hey,
Ive been trying to google this one but not coming up with anything concrete. 3mm seems to be the recommended gap, but expansion joints can be up to 15mm.

The reason for the question is that the gap above and below one of my windows (in the room Im reslabbing) is exactly 4ft. Naturally the slabs are 120cm wide so I have a gap of about 15mm each side.
Id hate to have to cut two boards, its a shocking waste and also means I end up with a nice cut edge butt joint right in the centre of the room.

The slab is 12.5mm plasterboard with 20mm insulation on the back. This is sitting on the vapour barrier which is over 50mm rigid insulation.
So I have two 15mm wide x 32.5mm deep gaps.

So, options?
- Should I fill before taping? Ive a concern about the fill having nothing to adhere to.
- Foam then fill/tape?
- Just tape?
- leave all the gap on one side (30mm) and fix 2 layers of 12.5mm plasterboard in the gap and then fill/skim?
- Use two boards


I asked the same question in the C&P forum but the thread was closed and the mod advised me to come here to get a "Bob the Builder" answer.:rolleyes:


Thanks Bob

Carlow52

I asked the same question in the C&P forum but the thread was closed and the mod advised me to come here to get a "Bob the Builder" answer

Wrong:
u got the answer in post 5 of ur post and obviously dont like it.
http://boards.ie/vbulletin/showthread.php?p=59584821#post59584821

2 suggestions,

turn sheet on side

get a narrower window

GreeBo

Carlow52 wrote: »

Wrong:

I can show you the pm if youd like?

Carlow52 wrote: »

u got the answer in post 5 of ur post and obviously dont like it.
http://boards.ie/vbulletin/showthread.php?p=59584821#post59584821

No matter how many times you say it, thats still not the answer to "What is the maximum gap between plasterboard joints?"

Carlow52 wrote: »

turn sheet on side

then I have tapered edges butting square edges which is far form ideal.

Carlow52 wrote: »

get a narrower window

:cool:

delly

My own opinion would be that GreeBo didn't get a fair run of his problem in the other thread, so I'm happy for it to be posted here.

gsxr1

I would shallow foam fill the the gap.

Joint filler

then tape.

it may well crack open again though.

If its not tight, its not right

2 stroke

Why bother using plasterboard at all if you aren't interested in its flame retardent properties. Its not just a decorative layer and needs to be done properly. A 15mm gap will pop in a fire allowing a fire path to other rooms.
This question was already answered, close the thread.

Carlow52

delly wrote: »

My own opinion would be that GreeBo didn't get a fair run of his problem in the other thread, so I'm happy for it to be posted here.

The correct answer will be got from both a reading of the relevant building regs and the technical guidance docs for the product he is using.

This would be the correct answer to the title of the post, however the OP goes on to describe in detail the issue he needs to resolve. Sinnerboy suggested a very workable solution.

gsxr1

2 stroke wrote: »

Why bother using plasterboard at all if you aren't interested in its flame retardent properties. Its not just a decorative layer and needs to be done properly. A 15mm gap will pop in a fire allowing a fire path to other rooms.
This question was already answered, close the thread.

Its a gap on an outside wall is it not. Being under a window. Its hardly a major fire risk.

He wants to use plasterboard so he can skim. What else would he use?

2 stroke

Too many think anybody can install plasterslab, and true, it is not rocket science but there are building regulations to follow.
last year I saw a restaurant opening, delayed 3 weeks over a similar issue. building failed insurance inspection when a ladder poked through bodged hardwall while inspectors were on premises. Inspectors would not have known otherwise but they delayed insurance untill the wall was reslabbed.

2 stroke

gsxr1 wrote: »

Its a gap on an outside wall is it not. Being under a window. Its hardly a major fire risk.

Its 4 gaps, 2 above and 2 below the window, and who knows what path a fire will take. also somebody may be depending on that window or one above as a fire escape.
Theres no room on this thread for bad advice, close the thread.

gsxr1

2 stroke wrote: »

Its 4 gaps, 2 above and 2 below the window, and who knows what path a fire will take. also somebody may be depending on that window or one above as a fire escape.
Theres no room on this thread for bad advice, close the thread.

would ya give over would ya.:p


no room hahaha.


It may crack . It would be hard to decorate.

but in all fairness have ya ever heard of someone getting burned to death over 15mm of joint filler and expanding foam. what a way to go!! On an outside battened wall!! With a 9 " block behind it...









Joint filler and bonding is used all over the house to fill bigger gaps than 15mm .

what about patching ??
Filling around beams

Holes for switching.

Filling around vents the list goes on....



OP for sure the best thing to do is to reslab. As I mentioned before it could crack but assuming its on a battened wall and not a stud (which is less likely to move) It might not crack.

2 stroke

Yes gsxr1, I agree there are badly built houses all over this country, in my mind plasterslab is a flameretardant coating and I have heard of fire travelling behind it from ground floor to upper floors, bypassing the flame retardant ceilings. If you aren't interested in the flameretardant properties you might as well use paper mache.