Plastering Calculator
Calculate how many bags of plaster and PVA you need for any wall or ceiling. Supports bonding, multi-finish, and one-coat plaster types with customisable thickness.
Frequently asked questions
How many bags of plaster do I need per m²?
For a standard 2mm skim coat of multi-finish plaster, a 25kg bag covers approximately 8–10m². For an 8mm bonding coat, a 25kg bag covers approximately 1.5–2m². Coverage varies by substrate condition and application thickness.
What is the difference between bonding and multi-finish plaster?
Bonding plaster (or browning) is an undercoat applied in thick layers (8–11mm) to provide a flat base. Multi-finish is a skim coat applied on top in thin layers (2–3mm) to give a smooth, paintable surface. Most replastering jobs require both.
Do I need PVA before plastering?
Yes — PVA (polyvinyl acetate) seals the surface and improves adhesion. Apply a diluted coat (1 part PVA to 3–4 parts water) and plaster while still tacky. This is especially important on absorbent surfaces like bare brick or old plaster.
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Plasterer? Quote and invoice from InvoiceAdept
Create professional quotes and invoices with itemised materials and labour. Send to clients by email or WhatsApp from your phone.
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