Painting over any mastic is not usually recommended. This is because of how difficult it is to seal and its tendency to bleed a dark color through the paint afterward. However, when it comes to painting over asbestos adhesive, it is possible.
Nonetheless, asbestos is very dangerous, especially when it becomes loose through chipping, cutting, or breaking. This can release its dangerous fibers into the air and, if inhaled, can be deadly. This is why the removal of any asbestos should only be handled by a certified asbestos abatement team. However, if the asbestos is not disturbed, you can paint, tile, carpet, or even laminate over it.
If you’re unsure whether the adhesive you’re dealing with is asbestos or not, there are some ways to check. Inspect the area to see if there are any black or dark marks underneath the surface. Asbestos mastic is always black so quite easy to recognize. This is easier to see if you have a cracked tile with black paste exposed beneath or around it. If the adhesive has been exposed to the air for a long time, it may have a gray tint to it.
Although you can paint over asbestos adhesive, it is always recommended that the asbestos is completely removed in the first place if it has become disturbed. While paint may seal the glue in some parts, it may not prevent certain parts from becoming broken. This can lead to asbestos fibers being released into the air and result in health problems.
You should always be extremely careful when dealing with asbestos. Be sure to wear protective clothing such as goggles, a face mask, and long-sleeved shirts. Nonetheless, if the asbestos adhesive is undisturbed, try and keep it that way. Sealing and adding primer to asbestos adhesive is considered a cheaper and easier option than removing the asbestos altogether. As long as the asbestos is completely sealed, it shouldn’t pose a threat to your health in the future but consider hiring a professional to make sure it’s completely sealed for good.