Plasterboard question

thehotstepper

Hi everyone,
I have a question about plasterboarding. If you want to just fill in the joints, ie.paint the paper, you use the sides with the tapered edge. But what do you do where the ends meet eachother? Its impossible to put tape on and plaster over or there will be a bump. If you dont use tape, it will crack after a few weeks, and therell be a line. So whats the norm?

O-Ninio

What you're referring to is known as taping and jointing at the joints use scrim, this is a kind of mesh tape. Give it a first coat with some joint filler you mix out yourself and then a second coat with the Lafarge ready mixed filler and finally sand it down.

thehotstepper

sorry, i've the brain of an under fed hamster today. I meant the ends, not the sides that are tapered, fine with them, but the ends where they butt up against eachother.

Corkey123

Did you use 8x4 sheets or the smaller slabs?

thehotstepper

Hi Martin, 8x4 sheets staggered on a ceiling.

Corkey123

thehopstepper

I know what you mean, normally this doesn't occur on most walls as they are normally us over 8 ft and there is usually no need to join at the butt end.

You must have a large ceiling, anyway what I would do is:

Check the join to remove any high pieces in the join, there are likely to be a few unless of course you are Michaelangelo.

Then using the scrim tape place it over the join

Use the joint filler, as thin a coat as possible, but enough to high the tape

When its dry sand each side of the join to bring it flush with the rest of the board.

I have done this on walls and it is surprisingly easy and works out well, however on a ceiling mmhh..a bit more difficult.

Goodluck

Cal

Should you not finish those end pieces on a joist? This would allow you to put a very fine layer of filler and it shouldn't crack as it is well supported.

This is not a professional view just my logic at work. There is possibly a reason this won't work that I haven't thought of.

Cal.

Steve

I've only done this on walls - but it works.

Use a router with a flat bottomed cutter to mill off 30mm strip x 3mm deep from each edge you are joining. Then use a SHARP blade to remove the furry edge. Don't nail or screw in the cut area when fixing - it will break. Fill the joint with scrim and powder joint filler. Finish with pro-fin and sand flush.

I've done this a few times, I'm sure there are pro's reading this and grimacing but I've not had a crack yet!

If you scrim / fill over a flush surface then the ceiling light will highlight the join and it'll look bad. If you're going to use downlighters then chances are you'll get away with it and never see the join.

The only other option is to plaster the entire ceiling - doesn't matter what kind of joins you use then.

p.s don't use the paper tape - it'll crack, get proper scrim tape. Its a fibreglass mesh which is slightly sticky on the back.

Steve

Cal wrote:

Should you not finish those end pieces on a joist? This would allow you to put a very fine layer of filler and it shouldn't crack as it is well supported.

This is not a professional view just my logic at work. There is possibly a reason this won't work that I haven't thought of.

Cal.

If you try to nail / screw plasterboard close to the edge it breaks. I think the recommended distance from the edge is at least 50mm. This rules out butt fixing 2 boards on a joist as you describe.

rooferPete

Hi,

Most use tape and a light bed of joint filler, when that dries you use Joint Finish and feather out any high points.

Personally I prefer the skimcoat finish but that requires the fast dying skills of the "Real Plasterer".

Taping and jointing is now the most popular finish in developments because it's fast and cheap, an artex finish (stipple) covers a multitude of sins including nailing too close to the edge of the boards.

.