Internal rendering after dpc

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paradise said:
Thanks rigsby nice advice..


so I'm going to


1-sbr slurry coat


2- first coat 4/1 with salt inhibitor and silka1 waterproofer whilst sbr wet
-- scratch and leave for 2 days


3- second coat 4.5/1 without salt inhibitor or waterproofer
-- scratch and leave for 2 days


4- third coat 4.5/1 no salt inhib or waterproofer then leave to dry out for 1 week


5- pva and skim as usual


obviously don't bridge the dpc - leave 2 inch gap from ground..
i think to use the grade m plastering sand as it sounds easier to use


Rigsby I would be over the moon if u could tell me if this sounds ok


Keithuk. - it's a paid job and it is true that I have to start somewhere. I'm a self taught plasterer (bonding and skimming) and in the past 6 months put myself out there. No complaints yet.
if it f@&ks up I will stay till it's correct!


I understand I'm going to sound naive but anyway thanks for the replies everyone


:)
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Washed plastering sand 4/1 with waterproofer two coat work all in the same day , set next day , unless high ground levels then a whole new ball game , best of luck , but keep away from damp work if you can
 
keithuk said:
Washed plastering sand 4/1 with waterproofer two coat work all in the same day , set next day , unless high ground levels then a whole new ball game , best of luck , but keep away from damp work if you can
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Not a leave it for a week man then Keith, I never did before the forum guys advised
 
johniosaif said:
Not a leave it for a week man then Keith, I never did before the forum guys advised
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No mate ,i started of in the Damp game , family company about 28 years ago and that was always the way ,some did use sharp sand ,but found the mix was so strong it cracked a lot , not saying what is right or wrong John ,just how i was told to do it , and still do mate
 
If it is 20mm why? that is thick for render or plaster. If it has to be 20mm then 3 coats, 2 coats and you risk cracking. Time left in-between coats is to allow for shrinkage but some have to chance it because of time restrictions.

Your second coat might slide because it is on a waterproof background. put it on as near as damn it and don't play with it or it will slide off. The third coat however will have some suction so some grab. If it sucks too much then wet down a bit to make it manageable. Rule off flat and use a devil float (float with nails in) to key. You hopefully will not need to use a pva as this might cause condensation problems later. Skim straight on and if required wet the s&c down to control suction.

If you used water proofer in each coat like some do then you might then get condensation settling on the top and giving the impression of damp is still there. Using Dri-coat or Limelite is a safer bet (do not use a bonding agent) but is a dog to use in the hands of a novice. Rush the stuff and it cracks. Multi coats a day apart is safer and easier.
 
Rigsby said:
If it is 20mm why? that is thick for render or plaster. If it has to be 20mm then 3 coats, 2 coats and you risk cracking. Time left in-between coats is to allow for shrinkage but some have to chance it because of time restrictions.

Your second coat might slide because it is on a waterproof background. put it on as near as damn it and don't play with it or it will slide off. The third coat however will have some suction so some grab. If it sucks too much then wet down a bit to make it manageable. Rule off flat and use a devil float (float with nails in) to key. You hopefully will not need to use a pva as this might cause condensation problems later. Skim straight on and if required wet the s&c down to control suction.

If you used water proofer in each coat like some do then you might then get condensation settling on the top and giving the impression of damp is still there. Using Dri-coat or Limelite is a safer bet (do not use a bonding agent) but is a dog to use in the hands of a novice. Rush the stuff and it cracks. Multi coats a day apart is safer and easier.
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Well said :)
 
never done any waterproofing myself, even though it's just rendering with different additives, albeit a bit more skillful, I have noticed no one mentioned adding any plas, some waterproofers have them added obviously and as far as i'm aware sika doesn't. So is not advisable to use plasticiser when tanking/damp proofing? cheers.
 
raytheplasterer said:
never done any waterproofing myself, even though it's just rendering with different additives, albeit a bit more skillful, I have noticed no one mentioned adding any plas, some waterproofers have them added obviously and as far as i'm aware sika doesn't. So is not advisable to use plasticiser when tanking/damp proofing? cheers.
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No. Plastisizer aerates which leaves spaces for water to pass through , I still see plasterers adding plasticiser to sika because they want it easier, easier yes but ruins the whole purpose
 
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