plastering plasterboard

[freepo]

Plasterboard has two sides, usually an ivory side and a matt paper side (i think).

Supposed to wallpaper onto ivory side and plaster onto matt paper side.

My ceiling boards are foil backed, and have been installed already with foil side in the loft, but the ceiling side is ivory, and I want to plaster them.

Will it be ok to plaster onto ivory side on a ceiling?

Other problem is that when installing I butted them too close and there is no gap between them. Will it be ok or do I have to use a router and cut a 3mm gap from all the joints?

Thanks

[mark.hannah]

I had the same 2 issues - and the plasterer had no problem making a good job. I think a coat of PVA on the ivory side will make it suitable for plastering.

Mark.

[sm_jamieson]

This has been dealt with many times. *These days*, the ivory side is used for all purposes. The other side has a glued flap of paper on it, and this flap can become unstuck if plastered over. Also, reportedly some plasterers like a gap between the boards to help bond them together. However, every time I have boarded for a plasterer to skim, I have butted them up and me or the plasterer has stuck the scrim tape over the joints. None of them said anything about expecting gaps ! Simon.

[freepo]

Cool nothing to worry about then. Thanks everyone.

[Lobster]

Well not long ago I boarded out several walls and ceilings with the aformentioned gap between the boards, and got ticked off when the plasterer arrived and told me he prefers the boards tight together.

So go figure...

David

[Roger]

The message from Lobster contains these words:

I am no expect on plastering but ISTM that if you plasterboard a ceiling without noggings at the board ends (not that I would) then a gap there for plaster to be forced through will do a better job than a tight joint and scrim tape. After all lath and plaster is just very short boards and a multitude of gaps.

[George]

Might be a bit late? but fill the gaps with acrylic sealant and wipe off excess,much better than scrim tape.

[Dave Plowman (News)]

Trouble is that finish coat is extremely hard and inflexible - as well as being very thin. Plasterboard is made of softer plaster - so any flexing gives obvious results at joins. Lath and plaster is different - the plaster used there is lime and very flexible. At least when new.

[Andrew Gabriel]

Correct, but you still use the scrim tape too, after you've forced the plaster through the gap.

You should really be forcing bonding coat through the gaps. Finish coat doesn't have much of a sticking/glueing property, and it shrinks enormously as it sets, so a 1/4" wad in a gap would definately crack along the gap. Of course, it's annoying mixing up a small quantity of bonding coat just for this, but if you're using it elsewhere, then you can just slap it in when you have it mixed up for other purposes.