Plasterboard and scrim.

As John Rumm said before, knock off a couple of inches of skim coat all around the hole (doesn't matter if you take some of the base/scratch coat off too). You want to make the plasterboard level with the 2" of wall all around where you have removed the finish coat plaster.

If you have a gap between the plasterboard and the wall, make it at least 1/4". Use plaster bonding coat to fill this gap -- force it in so it goes right through the tickness of the plasterboard, and oozes out on the back. This will very effectively bond the plasterboard to the wall. (You will need to have PVAed the wall side of the gap -- this is probably most easily done just before you start building the studding inside it, and repeat with a large brush in the gap 1/2 hour before plastering.) Also fill any holes you knocked in the original scratch/base coat.

Then for the finish coat, tape across the filled gap with scrim before applying first finish coat layer.

Glass tape no, hemp yes.

Can you tell me, please, why hemp is better, and would the same apply to ceiling boards?

Regards.

OK, thanks for the advice.

One other question, there is a chance that the stud and plasterboard will be slightly to low to allow for just a skim coat. Can I put browning on plasterboard? Or should I use another plaster that can go on thicker? Maybe one-coat? And maybe do it in two or three coats?

Thanks

I'm about to scrim&skim my basement wall - plaster board dry lining on studs. Its a high ceiling about 11ft, with about 100ft of wall . So, this sounds like a stupid question but; where to start - top or bottom, how to work - along in parallel lines at a convenient height e.g. starting on scaffold at the top and working around the room at that level, then from floor level? Or working top to bottom (or vice versa) in complete vertical areas? Or both - complete top area from scaffold tower, then finish area below, then move scaffold to next bit? Now I've written it down the last sounds the best way I suppose.

cheers

Jacob

You can put a scratch/base coat on plasterboard, but you then lost a lot of benefit of using plasterboard -- i.e. a nice flat surface to apply the finish coat to. I've not used browning myself, I always use bonding coat as a plaster scratch coat which would work (it sticks to just about anything, especially tools). Remember that the resultant wall will be heavier -- use more plasterboard screws.

Sorry, never tried one-coat so can't tell you its pros and cons.

I use plastering scrim tape, which I believe is glass tape, and it works fine.

Think, "Large bag of Polyfiller"

You'll find it easier to start at the bottom with the 'off cut' ie if using

And u won't notice the join due to not being at eye level.

Dave Jones

Thanks but I've done the boards - its the finish coat I'm contemplating for Monday morning.

cheers

Jacob