Skimming plasterboard walls - how thick

Hi all,

I'm doing our own bathroom. One wall has been lined with plasterboard, direct fix onto walls, but one of the boards is proud of its adjacent board by approx 1 to 1.5mm

How thick can I skim the wall to 'even out' this difference ?

Have the boards have been dot/dabbed onto the wall behind? If it’s done properly the boards should be flush, that’s the whole point! It is perfectly feasible to “fill out” to the adjacent board with plaster but if the boards aren’t basically level, they will need a levelling skim first or the finished wall will be all over the place & look awful.

Multi finish can easily take up 1 – 1 ½ mm & for an experienced plasterer it may easily be possible to do it in one hit but it really depends on what the rest of the wall is like. If the levels are out, it may be best to use Bonding plaster to provide a levelled base coat & then skim that with Multi finish but I would say your getting beyond the capabilities of a an inexperienced DIY plasterer. If it’s in a bathroom, have you used moisture resistant PB? & if it’s a wet area such as behind the bath or in a shower cubicle, you should use a cement backer board such as Aquapanel or tank the area. Ordinary PB or even moisture resistant will crumble fall apart once moisture get into it.

Hi Richard,

Thanks for a detailed reply.

OK - the wall is original plaster. The house was built in 1898 and if I ever find any wall / surface / frame or anything else which is truly plumb & flat ...... I'll pass out with shock

Made tiling a nightmare. The walls around the bath were as straight & true as a politician

Work below where the PB is (services to toilet, basin, etc..) caused some of the plaster to begin a slight crack in plaster surface. To make the upper wall look better, I've used moisture resilient PB from 3' height to ceilling.

PB is fastened to wall mechanically ( M6x60 nail-in fixings ) sunk below level of PB then skimmed with joint filler.

Wall wasn't flat to begin with, and to be honest, a perfectly flat 'new' wall would look kinda out of place in our property so all I'm looking to do is skim the wall to give a uniform finish.

The ceiling in the bedroom was D&D re-skimmed last year by pro's following storm damage to the roof (insurance claim) and I know is sounds daft but the billiard table smoothness of the ceiling compared to the old one looks out of place.

I have used true AquaPanel for all the wet area's or areas likely to become damp. When wet get this wall ready for painting, it'll be sealed again against dampness, just as an added extra to the moisture resilience of the PB, and all the paint we use will be suitable for the job in hand.

Fine; just thought I'd mention it.

rampump said:

The ceiling in the bedroom was D&D re-skimmed last year by pro's

Click to expand...

D&D on ceiling boards; not normal practice & hope gravity doesn’t take it's toll; could be interesting!