Damaged Lath and Plaster

Just use plasterboard screws to screw it to the studs underlying the laths (or use plasterboard nails even).

If this is a tiled wall subject to regular soaking (eg in a shower) you might want to consider a waterproof wallboard like Aquapanel instead of plasterboard - see the archives of this newsgroup for more info.

David

You might want to dab it with plasterboard adhesive instead as this will hold the laths too. If you strip the laths the edges of the void need blocking out so it could be a big job but getting the levels right would be easier with packing strips.

Wouldn't you rather strip the whole wall and start fresh? Tiling an old wall, you will never get a perfect match. And as you are doing a refurb the plumbing will need hiding in the walls.

I think doing the whole wall will be a step too far for me (and I have just bought some "handy panels" of plasterboard as a full panel won't fit in the car.

Another question:

I am going to locate the washbasin on this wall (where the Lath and Plaster is intact) - I am thinking of cutting out some pf the L & P and inserting some plywood where the basin needs to be attached. Any comments?

Not sure of meaning of "edges of void will need blocking out"

That is exactly what you do. They are called patresses. Set them back enough to cover them with the plasterboard.

The loose edges on bare studwork will flap if they go past a stud by more than a few inches. You have to put extra support in for it. With the laths left in place you won't need to.

Next time buy a whole sheet and cut it down to the size you want at the yard or have them do it. You must know someone with a van or have a shop that delivers such stuff somewhere nearby.