How to price a plastering job

Plastering looks simple from the outside: trowel it on, leave it to dry. The price, though, lives almost entirely in what's underneath and how much prep it needs. A skim over sound plasterboard is a quick job. Hacking off blown plaster, dot-and-dab boarding a wall and skimming it is a different one entirely. Price the two the same and you'll lose money on the hard one. Here is how to work out which job you're actually pricing, what to factor in, and how to structure the quote.

Work out which job you're pricing

The first question on any plastering job is the state of the existing surface, because that decides everything. Go and see it, run your hand over the walls, and tap for hollow or blown areas. A wall that just needs a fresh skim is worlds away from one that needs hacking back to brick and rebuilding.

• Skim only: sound plasterboard or existing plaster that just needs a smooth new finish.
• Overboard and skim: fixing fresh board over an uneven or tired surface, then skimming.
• Full re-plaster: hacking off blown or damp plaster, repairing the background, then re-skimming or floating and setting.
• Patch and make good: localised repairs after other trades, which are fiddlier per square metre than a clean wall.

Prep is most of the price

The skimming itself is the quick part. The cost is in everything before the trowel touches the wall. Be clear with yourself, and on the quote, about how much prep the job needs, because that's where a cheap-looking job turns expensive.

• Removing old, blown or flaking plaster and bagging the waste.
• Sorting the background: PVA or the right bonding, scrim on joints, beads on corners and reveals.
• Protecting floors, fittings and anything that isn't being plastered.
• Dealing with the cause if there's damp, because skimming over a damp wall just fails again.

Factor in drying time and access

Plaster needs time to dry before it can be painted, and that affects how the job sits in the customer's life, not just your day rate. Set the expectation plainly: fresh plaster typically needs to fully dry before decoration, and rushing it causes problems. If the customer or their decorator is following you, make clear when the wall will be ready. Also note access: a ceiling, a stairwell or a room full of furniture is slower than an empty room you can work freely in.

Price your own labour and materials

Work your labour from the realistic time the job takes including prep, drying-out gaps between coats, and clean-up, not just the skimming hours. Price your materials from your suppliers: plaster, board, beads, bonding, scrim and the consumables. Price your own materials and labour for the surface in front of you, because square-metre rates copied from someone else ignore the prep and the background, which is exactly what drives the cost.

Be clear about scope and finish

State plainly what's included: which walls or ceilings, to what finish, and whether you're making good around them. Spell out exclusions: if you're not removing furniture, decorating afterwards, or treating damp, say so. If the customer expects a glass-smooth finish ready to paint, confirm that's what you're providing, because a skim finish and a re-float are not the same thing and that mismatch causes complaints at the end. It's also worth noting whether small cracks are to be expected as the plaster dries and settles, so a hairline mark a week later isn't read as a fault in your work.

For the standard sections every quote should carry, see what every professional quote should include. If you can't tell how bad the background is until you start hacking off, our guide on quote vs estimate covers when to give a fixed price and when to estimate.