cracks in sand/cement render?

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BigAl

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Hi all,

Bought a 3 bed semi, 6 months ago and carried out a full refurb.
The property had damp, so we were advised to do the old, 'hack the plaster of to 1 meter' job and then sand and cement with intergal waterproofer render before skimming.
This was all done by a plasterer as well as re-skimming the whole house.

Now were moved in, I expect hairline cracks here and there, but what I have noticed is a horizontal hairline crack, right around every downstairs room at the height the plaster was hacked of to. Further to this there are other hairline cracks apperaing here and there in the plaster, again upto the height of the render.

Should the joint between the render and the original plaster have been skrimmed, as im not sure this was?

Any other thoughts, or ways I can repair the cracks would be appreciated.

Cheers

Allan
 
it sounds like your render was to strong a mix and brickwork to dry, deeds done like bubbles say caulk, polyfill .
 
dont think you could have avoided it , i did damp proofing for many years , problem is the render has to be a strongish mix to do its job and will shrink . the original plastering above wont shrink anymore , so somethings gotta give , it can take up to a year for the shrinkage to fully stop , as said just fill with a flexible filler and repaint , you may have to do it a couple of times though . i now put lime in the render to try and stop this . Dont think you can blame the plasterer on this isue
 
Thanks for the replys.

I have gone over with filler once, but as said, it will be needed again as a few have reappered.

Could this joint have been skrimmed? And would that have helped?

Cheers

Al
 
i always used to scrim it and blend in above... dont like running up to existing and stopping, no matter what you do, its always gonna shrink a tiny bit...
matter of preference for the spread...
I think blending in is easier anyway..
 
was ithe whole wall re skimmed if yes i suppose scrim cud of been used in that situation if not in my oppinion you dont normally scrim when blending in to solid plaster
 
was ithe whole wall re skimmed if yes i suppose scrim cud of been used in that situation if not in my oppinion you dont normally scrim when blending in to solid plaster

Yeah, every wall was fully re skimmed.
Guess some do, some dont. The render is going to shrink whatever. Il just be busy with the easi fill!

Cheers

Al
 
no lime in the mix,lime is flexible.

thank me later.

It can also have an adverse affect on water proofing additives, thats why a lot of company's won't spec lime when doing the render after a damp proof course, that's why it's better if poss to use limelite, dri-coat etc
 
It can also have an adverse affect on water proofing additives, thats why a lot of company's won't spec lime when doing the render after a damp proof course, that's why it's better if poss to use limelite, dri-coat etc

very true warrior , most of the damp companies i used to work for would not allow Lime in mix
 
dont think you could have avoided it , i did damp proofing for many years , problem is the render has to be a strongish mix to do its job and will shrink . the original plastering above wont shrink anymore , so somethings gotta give , it can take up to a year for the shrinkage to fully stop , as said just fill with a flexible filler and repaint , you may have to do it a couple of times though . i now put lime in the render to try and stop this . Dont think you can blame the plasterer on this isue

here here try telling that to private customers
 
what i would have done is rendered up to a meter hacked off any loose areas above that and patched them in then quick flick over with pva once set then tight 2mmish coat of bonding coat over the lot (clues in the name) skim this just as it is going solid(dont forget to key it)two coats 1 should suck in quite quick top coat will hang a bit more might bubble a bit dont worry last hard trowel right at end will push it all in trust me it works tried tested but some1 has to pay for it
 
never heard of a chemical company that would guarantee a product you stuck bonding straight over..
but fair crack if you get away with it... takes allsorts i suppose..
youre supposed to let the render cure before you skim it anyway...
 
never heard of a chemical company that would guarantee a product you stuck bonding straight over..
but fair crack if you get away with it... takes allsorts i suppose..
youre supposed to let the render cure before you skim it anyway...

one of the companies i used to work for had the bright idea to tell the customers that they would not skim for six months to avoid the cracking / crazing issue or there would be no guarentee , within a couple of weeks they changed there policy back once they stopped getting any work ! , its a bit of a fine balancing act
 
kinell 6 MONTHS! not surprised then..
the other problem i find is half the time you end up throwing it on silly thick cos the walls all over the bloody place..
never get any work though if you had to keep going back every week and adding another 12mil... :rolleyes)
some seem to be using the old platon/olroyd membranes these days for just about everything.. metre high, use bonding over the top..
 
To be honest Chris , i try to avoid the damp proofing /water proofing these days , more trouble than its worth sometimes , it was different when i was younger , there was big bucks in it but now everyone and his dog does it , having said that a mate of mine started his own membrane company a few years back and he is now minted , big bucks , but you gotta do what you gotta do , i dont like turning anything down
 
least you dont have to worry about 25 year insuranced backed guarantees to spray a bit of vinegar on the wall and stick an extractor fan in... :RpS_laugh: i wish they did a part p ticket just for extractor fans, id make a killin.. :RpS_bored:
 
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