Silicone caulk functions as a barrier to seal gaps between surfaces, preventing air and water entry. It forms a waterproof, tight seal that remains flexible, making it a good choice for bathroom, kitchens and laundry rooms. Applying silicone to drywall to seal gaps is typically not a good choice, because most silicone caulks are not paintable. Also, silicone caulk adheres very well to most surfaces, so removing it from drywall without causing too much damage is somewhat tricky.
Peel off as much silicone caulk as possible by hand. Peeling the silicone caulk may damage the paper covering on the drywall, making repairs after removal necessary.
Hold a glass scraper or razor blade parallel to the wall at the top or bottom of the silicone caulk bead. Slice through and shave the silicone caulk with the glass scraper or razor blade a little at a time, until only a very thin layer of silicone remains.
Sand the surface of the remaining caulk with 80-grit sandpaper, until a thin film remains. Do not sand all the way down to the drywall because 80-grit sandpaper is coarse and will abrade the paper covering.
Dip the edge of a nylon scrubbing-pad in white spirit and scrub the silicone caulk until it disappears. Do not use white spirit on a painted wall. If you will apply paintable caulk to the area where you're performing the caulk removal, stop the removal process when only a thin layer of silicone caulk remains. Apply the paintable caulk over the light layer of silicone caulk, feathering the edges so they cover all of the remaining silicone caulk. Silicone caulk provides an acceptable base for paintable caulk.
Wipe up as much caulk as possible with a rag. Wipe the silicone caulk from the edges toward the centre, to avoid spreading the caulk over a larger area.
Scrape the silicone caulk with a flexible scraper. Wipe the edge of the scraper with a rag to remove the caulk from the scraper with each pass.
Dip a rag in rubbing alcohol and rub the silicone caulk until no caulk remains on the drywall surface.
Wipe the area with a damp rag and an all-purpose cleaner to remove any rubbing alcohol residue.
Silicone caulk will fill in between the sanding grit, reducing its effectiveness, so keep changing the surface area of the sandpaper you're using. If you damage the surface of the drywall while scraping, make repairs with drywall joint compound. Ventilate any area where you use white spirit.
Do not use white spirit near an open flame.
Tips and warnings
- Silicone caulk will fill in between the sanding grit, reducing its effectiveness, so keep changing the surface area of the sandpaper you're using.
- If you damage the surface of the drywall while scraping, make repairs with drywall joint compound.
- Ventilate any area where you use white spirit.
- Do not use white spirit near an open flame.