They are actually caused by the slow buildup of dust soot and sometimes mold and there are several root causes behind the buildup.
Paint over soot ceiling.
Soot is easy to smear so if you use a regular sponge you risk pushing the soot farther into the wall and causing a permanent stain.
Dry cleaning sponges are specifically designed to absorb residue which makes them perfect for cleaning soot.
Most coatings don t do a good job of covering nicotine or other smoke stains on your ceilings.
On untextured ceilings it s a good idea to start with a quick once.
Soot and smoke from candles fireplaces or cigars and cigarettes can be quite unsightly on interior plaster or sheetrock walls and that smoky residue may also produce some unpleasant odors.
Simply covering the soot with low priced latex paint won t solve the problem.
Use a dry cleaning sponge.
Obviously nicotine staining is the result of people smoking cigarettes indoors.
Nicotine from heavy smoking can penetrate through the paint and settle into the pores of drywall leaving what seem permanent stains and odors which can.
If you apply a coat of ordinary white ceiling paint the stain will continue to bleed through and even a second coat may not hide it.
Instead they re made from vu.
Soot and smoke damage can come from wood burning fireplaces candles or a small kitchen fire.
How to paint over a heavy smoker s walls.
If you re painting over a ceiling that s yellow from smoke roll a coat of shellac over the entire ceiling before painting with latex.
Black carbon more commonly known as soot is caused by burning fuel.
How to repaint a sooty ceiling.
While this is not a problem outdoors when you burn fuel indoors the soot released into.
Since the soot from fireplaces cigarettes candle etc on sheetrock walls or interior plaster is many times not noticeable it may be tempting for you to paint over soot covered walls.
Dry cleaning sponges are also called chemical sponges but they don t contain any chemicals.
For best results start your painting job like the pros do with a stain killing primer.
Over time and as the layers of paint build up bumps and crud can get stuck to the ceiling.
Sand before you paint.