Yes, paint and coatings are tested when an old painted surface is going to be sanded, scraped or removed. Some older paints, textured coatings, spray-applied fillers and floor coatings may contain asbestos, and the paint layer is often sampled together with the filler beneath it. You cannot tell by looking, so the answer comes from a sample.
Can paint contain asbestos?
Asbestos in paint is possible but not a given. Asbestos was used as a filler and reinforcing agent in many building products, and some older paints and coatings may contain it. A thin, ordinary wall paint is rarely the survey’s only concern. Thicker, paste-like coatings and the filler beneath the paint are more often the reason a painted surface gets tested.
Because painted surfaces have been redone many times over the decades, a wall or floor can carry several layers from different periods. The top coat may be new even if there is a 1970s coating underneath. That is why you cannot judge the age of a surface from the top layer of paint.
Which paints and coatings may contain asbestos?
A survey pays particular attention to these surfaces when they date from before 1994:
- Textured paints and patterned coatings, meaning thick, patterned finishes on walls and ceilings.
- Spray-applied fillers used to give ceilings and walls a rough or patterned finish.
- Floor paints and floor coatings in basements, washrooms, garages and technical rooms.
- Bitumen-based coatings and brush-on waterproofing, for example in wet rooms and foundations.
- Old paint layers over filler, where the filler itself may contain asbestos.
The list does not mean every such surface contains asbestos. It means these surfaces are worth checking before work starts. Bear in mind too that paint can hide other materials: a painted pipe may have old insulation underneath and a painted joint may hide a sealant, and these are tested separately.
Why is paint tested together with the filler?
A paint layer is thin and bonded to what lies beneath. When the surface is sanded or scraped, both paint and the filler under it come away. That is why the sample is usually taken so that it includes the paint and the filler right down to the substrate. The result then tells you whether the work could release asbestos, not just whether the thin paint film contains fibres.
Fillers are among the most common asbestos finds in old walls and ceilings. Read more about asbestos in wall filler. If the painted surface sits on wallpaper or the wall has a textured filler wallpaper, see also asbestos in wallpaper.
Which painting jobs carry a risk?
An intact painted surface left in place does not usually release fibres. The risk arises when the surface is broken. Jobs like these include:
- Sanding by hand or machine before a new coat.
- Scraping to remove flaking or old paint.
- Sanding or grinding a floor coating before a new coating or floor covering.
- Drilling and chiselling into painted walls and ceilings.
- Removing filler and coatings, for example before tiling.
Washing an intact surface and applying new paint without sanding does not loosen the old coating in the same way. In practice, though, repainting almost always involves some patching and sanding, so the old surface should be tested before work begins. If the building or coating dates from before 1994 and surfaces are removed or worked on, an asbestos survey is required under Finland’s Asbestos Act (684/2015) and Government Decree 798/2015.
What about exterior paint and painted boards?
The same principle applies outdoors. Old coatings on facades, plinths and roofs are tested if they are going to be sanded, scraped or blasted off with a pressure washer. Painted boards need special attention: there may be an asbestos-cement board under the paint, in which case the board itself, not the paint, is the source of asbestos. A painted board should not be sanded or pressure-washed until its material has been identified.
What if the surface has already been sanded?
Stop work and close off the room. Do not sweep up the dust or use an ordinary vacuum cleaner on it, as that spreads fine dust. Take a sample from the sanded surface and wait for the result. If the surface contains asbestos, it is best to leave the clean-up to an authorised asbestos removal contractor.
How do you take an asbestos sample from paint?
Take the sample from a spot that represents the whole surface, and include every layer down to the substrate:
- Protect yourself with disposable gloves and an FFP3 respirator.
- Wet the surface so no dust is produced.
- Remove a piece a few centimetres across that includes both the paint and the filler or coating beneath it.
- Seal the sample straight away in an airtight bag and note where it was taken.
- Take a separate sample from each different surface, for example the spray-applied filler on the ceiling and the textured paint on the wall.
The samples are analysed in the laboratory with a JEOL SEM-EDS electron microscope. If you want to test a single surface, you can send a sample by post for 39,90 € + VAT per sample. For a larger renovation involving several surfaces, a survey is the safer choice. Depending on the city, it costs from 119 € incl. VAT, and the price includes the survey, all samples, the laboratory analysis, travel and the report. The surveyor visits on site in Southern Finland. See the price for your city in the price list.
If the result is positive, the surface must be removed by an authorised asbestos removal contractor. If no asbestos is found, the painting and coating work can go ahead as normal.