Short answer
Yes, if it’s an acrylic like Pereseal 702 or FR and it has dried. No for ordinary silicone: paint won’t stick to it. Even on a paintable sealant, the paint will crack if the joint moves more than the paint film can stretch.
Cracked paint over a sealant joint usually comes down to one of three things: the wrong sealant, painting too soon, or a joint that moves more than paint can take.
Use an acrylic
Water-based acrylic is the sealant for painted work. Pereseal 702 takes paint very well, and it’s the one we recommend for gaps round frames, skirting, cornices, plasterboard joints and wall cracks. Pereseal FR, our fire-rated acrylic, is paintable too.
Some polyurethane and hybrid sealants can be painted as well. We don’t make those, so follow the maker’s instructions if you use one.
Don’t paint silicone
Paint doesn’t bond to cured silicone. It beads up, stays patchy or peels off in strips. Our N and AF data sheets say it plainly: not for paint coatings. Sanding or priming ordinary silicone doesn’t change that.
If the joint has to be silicone and has to match the wall, choose a close sealant colour. Our silicones come in white, grey, black and clear, depending on the product. If the joint doesn’t need silicone, cut it out and use 702.
Wait until it’s dry
702 skins in about 20 minutes, but a skin isn’t dry. The data sheet says to keep it away from water for 24 hours, and a water-based paint is mostly water. Leave it at least a day before painting, and longer for a deep bead or in wet weather. Paint put on too early can stay soft, crack or discolour over the joint.
Mind the movement
Paint is far less stretchy than sealant. 702 handles ±15% movement, but the paint film over it cracks long before that. On a joint that barely moves, like a skirting board, a cornice or a settled plaster crack, that’s fine. On a joint that opens and closes every day in the sun, expect a hairline crack in the paint even when the sealant underneath is intact.
For a real movement joint, leave the sealant unpainted in a matching colour. For a crack that keeps reopening, find out why before you fill it again.
Test first on a big job
Run a short bead on the actual surface, let it dry, put on the full paint system and look at it a few days later. Check for cracking, stickiness and colour change. It takes an afternoon and saves repainting a whole floor.
Keep paint coats to their normal thickness. A heavy build-up over the joint cracks more visibly and dries slowly.
If it has already cracked
A fine crack along the middle of the joint means movement or shrinkage. Paint peeling from the edges points to dust, oil or silicone residue underneath. Paint that stays tacky usually went on too soon.
If the sealant is still stuck and rubbery, it’s a paint problem: repaint lightly, or leave the joint unpainted. If the sealant has let go, cut it out and start again. See why sealant joints fail.
Paintable gaps: use 702
Acrylic sealant for frames, skirting, partitions and wall cracks. Takes paint very well. 300 ml cartridges and 400 or 600 ml sausages.
See Pereseal 702
