Drywall adhesive is a modified gypsum mortar with high adhesive strength, made for sticking boards onto a masonry background. It is applied in dabs: blobs of adhesive on the board or the wall, board pressed on, then aligned and plumbed. The Dutch term is kleefgips; well-known products include Knauf Perlfix and Gyproc adhesive.
The technique is known as dot-and-dab or dry lining: instead of plastering a wall in several coats and waiting for each to dry, you hang a flat board in front of it.
Where it is used
- Levelling uneven walls — poor brickwork, rough concrete or coarse render gets a flat board surface
- Bonding insulation — insulated laminate boards (plasterboard bonded to rigid foam or mineral wool) on an inside wall
- Fast renovation — no battens or metal framing needed, and you lose only a few centimetres of room
- Local repair — levelling one wall in a room without replastering the rest
Application
- Thickness — the adhesive bridges irregularities of roughly 5 to 40 mm; where the wall is more out of true, a framed lining is the better choice
- Background — sound, dust-free and free of loose material; very dry, absorbent walls should be dampened or primed first
- Working time — gypsum sets quickly; only mix what you can use within the open time, and always use clean water and a clean bucket (set residues speed up the reaction)
What it will not do
Drywall adhesive does not bond to damp walls, wallpaper, painted surfaces or smooth non-absorbent surfaces. Where damp penetrates or rises, a board stuck to the wall is not a solution — the cause of the damp has to be dealt with first. In permanently wet rooms gypsum is the wrong binder altogether; use a cement-based board and a cement-based adhesive there.
Related terms
- Plasterboard
- Gypsum
- Adhesive mortar
- Metal stud
- Plaster coat
- Primer
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