How do you safely strip wallpaper, woodchip paper and artex from plaster, restore loose and cracked plaster, and replace missing plaster from internal walls?
Plaster was usually originally painted with distemper. This is water-soluble and can be removed with a soft brush and hot, soapy water. A small quantity of wallpaper stripper in the water is sometimes effective. For complex mouldings, wet a little at a time and use a brush and toothpick to remove the distemper. Wash thoroughly with clean water.
However, in most cases the distemper has been over-painted with modern oil-based paints which are best removed with a solvent-based stripper. Do not use an alkali-based stripper as this can damage plaster. Dab the stripper into details with a stiff brush and an artist's palette knife. Protect your hands with gloves or simply strong polythene bags.
If the paint is very thick, use a poultice stripper; cover the stripper with the sealing sheets supplied or with clingfilm. After one or two days, peel them off, and they should lift away much of the paint. You may be left with the underlying distemper which you can wash off, as above.
Wash off all the traces of stripper. Use a paint brush to help penetrate all the details in the plaster. Allow the plaster to dry for several days before repainting. The best results are achieved using a distemper which is available from specialist paint suppliers. This gives a wonderful chalky finish, and of course, can be simply washed off in future when redecorating.
Decorative coatings that were put on before the mid-1980's usually contain a form of asbestos. This represents a significant health hazard if the fibres become airborne and are breathed in. The removal of this type of material needs to be done with care. Asbestos removal companies are licensed by the Health and Safety Executive (HSE). The HSE provides free information on this. As a homeowner, if you employ someone to remove the coating, then they should be licensed. If you do it yourself, then you should follow all the precautions both for your health but for the health of your family.
If the artex is on plaster, try a wallpaper steamer. The steam should cause the artex to split from the plaster and you can then scrape it off with a small plasterer's blade. If the artex has a lot of plastic or latex in it, the wallpaper steamer will soften it enough to scrape and peel it away. A gypsum-based artex should start to disintegrate once soaked with enough hot water and you can scrape it off.
If the artex has really stuck on and you still want to save the plaster underneath, the only way is to get underneath it and carefully and slowly lever it off with a small plasterers blade.
The final option is to strip the plaster and artex from the wall or ceiling and replace.
A wallpaper steamer is a useful tool for this, or use a garden sprayer with hot water. Scrape the surface, cutting though the paint layer; use a flat cheese grater, serrated steel roller or a toothed scraper. This helps the steam and water to soak in.
Do not hold the steamer in one place for too long or you can damage the plaster or plasterboard.
Small areas of loose plaster can be ignored; use a heavy lining paper before wallpapering or painting.
To fill fine cracks, scratch along their length to widen them and remove any loose plaster. Use a fine surface filler; spread it with a filling knife across the crack and then finish along the crack.
With larger cracks, solve the cause first and then use a bolster chisel to chop away and undercut the edges of the crack. Rake out the loose debris. Moisten the plaster thoroughly, and then apply a filler in layers, or plaster of Paris and then a coating of surface filler. Once it has set hard, use sandpaper to smooth the surface.
Plastering is one of those skills which is difficult for most DIY-ers to master. Small areas of less than a square metre are not too daunting and you may be able to achieve a reasonably level and smooth finish.
Ideally the new plaster should match the composition of the original; subsequent fine cracks between the old and new areas are less likely. You can use a modern plaster instead but expect cracks and it can exacerbate damp problems.
You can carefully remove only the damaged plaster - usually from waist to shoulder height, and then get a plasterer in to replaster. This is usually a good approach if you want to avoid disturbing cornices and picture rails.
If you opt for plasterboard, remove the old plaster. With stud walls, remove the laths, and all the nails, and then add 'noggins' - 8cm x 5cm horizontal pieces of wood between the 'studs' (the verticals); you will need one row to support the top and bottom of each sheet of plaster board - so typically one at the bottom, and other at 1 metre up, another at 2 metres, and one for the top. These are nailed at an angle into the studs. Use a large G-cramp to help. Plasterboard is nailed to a stud wall or fixed to brickwork with patches of plaster.
Deal with the source of the staining first. If it is due to damp, investigate the source of the moisture and solve the problem. Leave the wall to dry out for as long as possible – at least two or three months.
If there are black specks of mould, apply a fungicide.
The staining should then be sealed. For most stains, an aluminium alcohol-based sealant is effective.
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