Dimples / Bubbles in new Plaster

Discussion in 'Getting Started FAQ' started by Thoob, Feb 13, 2018.

  1. Thoob

    Thoob New Member

    I have had some plastering work done a week ago by a company who also do damp proofing which I also had done at the same time. I was quite happy with the work completed and up to a week ago the walls were very smooth. However Dimples have started to appear over the the plaster resulting it feeling bumpy in places (but not every where)

    Can these be simply sanded down or should I get the plaster back to take a look?
     

    Attached Files:

  2. Astramax

    Astramax Well-Known Member

    Similar post a couple of weeks ago.
     
  3. Longy75

    Longy75 Member

    Were the walls taken back to brick? And if they were what did they use for the undercoat?
     
  4. Thoob

    Thoob New Member

    Yes the walls were taken back to brick. I don't no what the undercoat was however the mix used was inline with recommended guidelines in damp areas. So a retardant additive has been used etc. I have emailed the company for their advice but I wanted a second opinion really if possible.
     

    Attached Files:

  5. Longy75

    Longy75 Member

    Hopefully from what you've just posted they did a sand and cement render and not used a thistle undercoat plaster as they're not really suitable where damp has been an issue, unless it's dri coat.
    As Astra said there was a similar post a while ago regarding blebbing where the skim is put on a backing coat which is either still too wet or has not been floated properly and creates little air pockets which show as blisters in the finish.
    How long was it left before they skimmed it?
     
  6. Thoob

    Thoob New Member

    I'm not sure to be honest they were just finishing up when I got back from work. The plasterer was very knowledgeable and professional (I got the feeling anyway); so from what your saying it could be down to a timing issue and not letting it dry properly you think? What are the fixes can it be simply sanded down or should I get them back to re-skim or something? The work is guaranteed because the damping system and plastering was done as a job lot.
     
  7. Longy75

    Longy75 Member

    If they used s & c render this really should have been left for at least a week before skimming, as it can cause the plaster to blow if done too soon, either way you probably could get round it with sanding and filling, however why should you? You paid for a service, get them back to rectify it
     
  8. Thoob

    Thoob New Member

    Thanks so much for your advice. I'm still waiting to here back from them but your right why should I! thanks again.
     
  9. Longy75

    Longy75 Member

    Hopefully they'll resolve it for you, see if you can find out what materials they used, my concern would be the skim blowing in the future due to not leaving the render long enough to dry and where do you stand if it does.
     
  10. Thoob

    Thoob New Member

    From what I can gather the company always render and plaster in the same day I was never advised that it would need a week to dry then they would come back to finish. I'm sure they treat all their customers the same.

    The plasterer did advise that it would take between 4-6 weeks to dry properly however as a minimum before re-decoration.
     
  11. Longy75

    Longy75 Member

    Unfortunately a lot of damp proof companies do it all the same day to save coming back, ideally the render needs time to cure before being skimmed as that's when it's likely to craze or crack and therefore compromising your finish coat, his drying times are testament to that as the s&c is trying to dry out behind the finish coat, if it was left to cure then skimmed you're only looking at a couple of weeks before you can decorate
     
    KIAB likes this.
  12. KIAB

    KIAB Well-Known Member

    Spot on.

    A lot of peeps don't realise there a lot of moisture to evapourate in a s & c, & slapping on a coat of plaster before it's fully will cause no end of problems,like the risk of the skim blowing, as already mentioned.
     
    Longy75 likes this.
  13. Thoob

    Thoob New Member

    Thanks again. Still waiting with baited breath on their reply...
     
  14. Longy75

    Longy75 Member

    Especially this time of year, spend most of the day waiting for stuff to set :(
     
    KIAB likes this.
  15. Dr Bodgit

    Dr Bodgit Well-Known Member

    Some deep bonding and plaster took about 6 weeks to dry in my bathroom.
     
  16. KIAB

    KIAB Well-Known Member

    It's the same problem with traditional s&c floor screeds drying time, peeps don't realise a 65mm floor screed needs around 6- 8 weeks to be throughly dry, & humidity & temperature can also affect this time.

    A lot to be said for a free flowing screed,more costly, but drying can be speeded up with a dehumidifer, so you can get down the final floor finish quicker.:)
     
    Dr Bodgit likes this.
  17. Dr Bodgit

    Dr Bodgit Well-Known Member

    Even longer when you have a leak...
     
    KIAB likes this.
  18. KIAB

    KIAB Well-Known Member

    Your plumbing that bad....:p
     
  19. Dr Bodgit

    Dr Bodgit Well-Known Member

    Not mine, 'twas the "professional" plumber that gave me the leaks!!! All my CH pipework is in place now, this weekend the soldering gets done then hopefully, after 2 months without CH, the boiler can be fired up.
     

Share This Page