Our end goal is to mud over the existing plaster walls/texture to create a smooth finish. Before this we want to repair several hairline cracks to prevent them from recurring. After scraping open the hairline crack we plan to add caulk inside the new, wider crack, but not fill the space all the way to the surface, leaving room for a sandable Durabond to bring it flush to the surface. Our thinking is that the caulk would allow for flexibility at the back of the crack and the Durabond would allow for better control of the surface sanding process. We would appreciate any insight into this process.

  • NO idea if this is a good idea or not (some expert please chime in) but if you are re-coating the entire wall, I'd suggest just covering the cracks with fiberglass tape.
    – DA01
    Jun 6 '12 at 18:11
  • Your suggestion might be a good one...never thought of it. I do hope an expert chimes in, just in case we are about to do something in error. Our problem is that there are too many opinions on other sites, many of them differing from one another, and we need to know the 'bottom line'. Thanks for your input.
    – RET
    Jun 6 '12 at 21:09

Fiberglass tape and a couple coats of compound will give you the best results.

Just a thought not sure how textured your walls are that you're trying to smooth out but sometimes this can be more work and leave you with inferior results instead of just taking it down and replacing with drywall.


I have worked on several high end homes with plaster walls over the years along with many hair line crack. I'm an expert drywall finisher with 30 years under my belt so for best results I would contact your local drywall company. Remember - Drywall Finishing is an art - it is not something you can pick up as a DIY and expect expert results. But my personal success on the question is as follows.

  • Open hairline crack by scraping with razor knife 45 angle
  • Sponge or wet rag over crack to remove plaster dust
  • Use mesh or fiberglass tape with either durabond or USG All Purpose (GREEN CAN)
  • Build out taped areas as a but joint
  • Sand entire area knocking down any sand texture or multiple layers of paint.
  • I top with 2 coats- 1 USG Green all purpose followed by 1 USG Lightweight Blue can. I hope this helps
  • Good answer but depending on what type of wall he has, there might be a need to reanchor the plaster to the lathe (if there is lathe). I find Plaster Magic to be the easiest system for repairing cracks for the homeowner.
    – figtrap
    Apr 12 '18 at 15:24

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