Old and crumbling loose plaster and lath

Sure you can screw plastrboerd over .Only thing carfully install plastrboards dont let plaster fall off between new pasterboards and wall

Although not the recommended way , Yes this can be done although there are a couple of things to keep in mind such as the skirtings if you over bored any wall the skirtings will be effected so maybe they will need taking off and replacing after also Any electric points upon this wall will need longer screws when re screwing the face back on Also you will need to locate the stud and not just screw the plasterboard In to the lath when mechanically fixing ( screwing ) Its essential to get a good fixing to avoid future problems such as bouncing cracking or worst case complete fail of the work When choosing the Plasterbored there are two considerations to think of Standard Plasterbored comes in two main thickness 9.5 mm and 12.5 you can use 9.5 mm (thickness ) bored when over boarding to save the space but 12.5 is much stronger And there are two sizes (area ) of bored 8x4 (2400x1200) 6x3 (1800x900) Although 8x4 will cover a larger area per bored The 6x3 are much simpler to work with Hope this helps Jmbm

Yes it can be. The best solution would be to remove and install new plasterboard but as long as the wall is relatively plumb, over boarding is fine. Consideration should be taken that old skirting board may need to be removed and replaced in most cases with new.

Yes, overboarding can sometimes be done without removing all of the wallpaper and old plaster, but it depends on how loose and deteriorated the existing lath and plaster is. If the wall is still reasonably stable, overboarding may be a suitable option. However, if large areas are loose or detached, some removal and repairs may be required first to ensure a solid and long-lasting finish.