Plastering FAQs: answers for London homes
Practical answers about existing plaster, drying, cracks, preparation and quotes. Choose a topic, then follow the detailed guide when you need more than a quick answer.
Existing walls and finishes
What does skimming actually mean?
A skim is a thin plaster finish over a suitable background. It gives the surface a fresh finish, but it doesn’t replace the need to assess what is underneath. See our skimming service for the work we can discuss.
How do I know whether old plaster can stay?
That needs an assessment of its condition and attachment to the background. Tell us about loose areas, previous repairs or cracks you’ve noticed. A photograph can start the discussion, but it cannot confirm everything about the wall.
Can a skim make a crooked wall straight?
A smoother finish and a straighter wall are different aims. If alignment matters—for example, beside fitted furniture—say so before the work is priced. Ask whether levelling or other preparation is needed rather than assuming a thin finish will correct the shape.
Does wallpaper need to come off first?
Wallpaper generally needs to be removed so the wall beneath can be assessed and prepared. Agree who will do that work. If you uncover loose material or an unfamiliar coating, pause and discuss it rather than continuing to strip everything back.
Can you plaster over a painted surface?
Sometimes, but the paint and the surface beneath it must be suitable. British Gypsum says both need to be in very good condition. A plasterer should assess adhesion and preparation before recommending a finish. See the manufacturer’s painted-wall guidance.
What is the difference between plasterboard and plaster?
Plasterboard forms or lines a wall or ceiling; plaster can provide its finish. The board, fixings and finishing method need to suit the project. If boards are already installed, tell us which type was used, if known.
What does overboarding involve?
It means installing a new layer of plasterboard over an existing surface. Whether it is suitable depends on the construction, condition and fixing arrangements. It needs assessment; it is not an automatic answer to every damaged ceiling.
Can bare brickwork be plastered?
Brickwork can be a background for a suitable plaster system, but its condition and the building’s construction matter. Share whether the wall is newly built or exposed during renovation, and mention any moisture or previous coatings.
Drying and decorating
Is plaster ready to paint as soon as it feels hard?
No. Setting and drying are different stages. British Gypsum advises that gypsum plaster should be thoroughly dry before final decoration. Ask for guidance for the material used on your job rather than judging readiness by hardness alone.
How many days should I leave before decorating?
There isn’t a reliable countdown for every room. Thickness and the conditions in the property affect drying. Ask the plasterer what to expect for the actual work, and keep the decorating date flexible until the surface is ready.
What should the first coat of paint be?
Follow the plaster and paint manufacturers’ instructions for the products being used. The required first coat, primer or dilution can differ, so avoid a universal “mist coat” recipe. Tell your decorator which plaster was applied.
Should I turn the heating up to dry the walls faster?
Ask for the drying advice for your project before changing the room conditions. Don’t aim intense heat at fresh plaster or assume rapid surface drying means the whole layer is dry. Keep the next trade informed if the programme changes.
Cracks, moisture and textured coatings
Will plastering stop a crack coming back?
A repair can address the visible damage, but it does not by itself explain the cause. Show us where the crack is and whether it has returned after an earlier repair. Significant, changing or recurring cracks need assessment before cosmetic work is agreed.
What should I do if new plaster has cracked?
Contact the person who carried out the work before filling or painting over it. Send a close-up and a wider view, say when you noticed it and whether it is changing. Those details help with assessment; a photo alone does not establish the cause.
Can a damp wall simply be covered with new plaster?
The source of the moisture needs attention first. Explain where the damp appears, when it started and whether the cause has been investigated. A new finish should not be used to hide an unresolved moisture problem.
Can a ceiling be replastered after a leak?
The leak needs to be resolved and the ceiling assessed before finishing work. Tell us whether there is continuing moisture, loose material or visible deformation. Keep clear of a sagging or unstable area and arrange an assessment rather than treating it as a decorating job.
Can you skim over Artex or another textured coating?
The coating needs assessment before anyone disturbs it. Some older textured coatings contain asbestos; appearance alone cannot confirm whether it is present. Do not sand, scrape or drill a suspect coating. Get competent advice about identification and the proposed work first. Read HSE’s guidance on asbestos materials.
Preparing for the work
What can I do before the plasterer arrives?
Confirm room clearance, access, parking and protection arrangements. Move belongings only as agreed, and mention items that cannot be moved. It is better to identify an access problem beforehand than discover it when materials arrive.
Will there be dust and mess?
Some stages, particularly removal and preparation, can create dust and debris. Discuss protection and cleanup as part of the scope. Ask how nearby rooms and shared access routes will be handled if the property stays occupied.
Who removes old plaster and takes away the waste?
This should be stated in the quotation. Removal, disposal and final cleanup are separate details worth checking. Make sure you know which are included and whether you need to arrange anything yourself.
How much time should I allow for the job?
Ask for time on site and drying time separately. The surface condition, work involved and access affect the programme. A room’s dimensions alone cannot give a dependable completion date.
Can I send photos instead of arranging a visit?
Photos are helpful for an initial discussion. Include a whole-wall or whole-ceiling view, a close-up of the issue and something that gives a sense of scale. Some details still need an assessment before the work can be confirmed.
Prices and choosing a service
Where can I find a guide to plastering prices?
Our plastering price guide explains the supplied rate ranges and a worked room example. Use the cost calculator to explore dimensions and options. Both are starting points for budgeting, not a confirmed quotation.
What if I don’t know which service to ask for?
Describe the result you want and what is wrong with the current surface. You don’t need to diagnose the wall or choose a product. We can discuss whether the next step is a repair enquiry, skimming assessment or a more detailed look at the project.
Does a new skim provide insulation or soundproofing?
Do not treat a finishing skim as a substitute for an insulation or acoustic system. If warmth or noise is the main concern, explain that at the outset so the wall or ceiling construction can be considered as a whole.
How can I compare plasterers before booking?
Look for relevant work examples and clear explanations of the proposed work. Our plasterer hiring guide has a comparison checklist; the company page explains how to put together a project brief.
More detailed product and safety guidance
For material-specific instructions, use British Gypsum’s installation guidance and the instructions for your chosen paint. For suspect textured coatings, refer to HSE’s asbestos guidance before planning any disturbance.
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