S&c cracking on soft reds

Joined
25 Mar 2017
Messages
4
Reaction score
0
Country
United Kingdom
Hello

Long time lurker first time poster.

I've had my 1920's home fully dpc injected and all the downstairs stripped of all original black ash/sand/lime plaster (we took it all off, not just the lower part as it was blown in places anyway).

Unfortunately we are not able to re-render/plaster with the same materials (lime) as the new dpc spec requires a s&c backing. Obviously much stronger than lime so not ideal but we decided to go ahead after lots of research/advice (looked into renovation plasters but would invalidate guarantee).

The plan was for two coats of s&c to flat out the walls and then skim with multi. When the plasterer came to do the job he advised that its common to get lots of cracking (he described it as jigsaw puzzle like cracking) when plastering on our type of soft red bricks and suggested that he do the first s&c scratch for the damp proofing then dot and dab.

The scratch has been done and he says if we really want to go ahead with skim then he will come back and do the second s&c then skim but really advises against it.

We're not very keen on d&d and were really hoping for a solid skimmed finish. I'm wondering if leaving as much time as possible between the s&c backing and skim would minimise the risk of cracking? Would it be completely bananas to line all the walls with fibreglass mesh before the skim coats as an extra precaution?

Any advice would be greatly appreciated!
 
Sponsored Links
Seems all very strange to me. So the scratch coat, presumably with some form of waterproofer in the mix such as renderguard gold or similar is on? If this has gone on ok, with presumably no 'cracking' then there would be no reason that a second render coat would be problematic.

Maybe your 'plasterer' doesn't like the idea of getting a float coat on bang on plumb and level ready for skimming. Dot and dabbing it now just seems like a cop out on his part. If you want a solid render and skim finish, then there should be no reason why you shouldn't get it. What does the scratch coat look like anyway, have you any photos?
 
Seems all very strange to me. So the scratch coat, presumably with some form of waterproofer in the mix such as renderguard gold or similar is on? If this has gone on ok, with presumably no 'cracking' then there would be no reason that a second render coat would be problematic.

Maybe your 'plasterer' doesn't like the idea of getting a float coat on bang on plumb and level ready for skimming. Dot and dabbing it now just seems like a cop out on his part. If you want a solid render and skim finish, then there should be no reason why you shouldn't get it. What does the scratch coat look like anyway, have you any photos?
Hi chris_o

thank you for your reply!

Yes, scratch is on - photos attached. And yes I provided the plasterer with Soverign Rendermix waterproofer/salt inhibitor.

What you say regarding getting the float right has run through my mind.

I've attached a photo of the background for reference too.

Thanks again for your input.
WP_20170324_16_14_51_Pro.jpg
WP_20170324_16_15_12_Pro.jpg
WP_20170324_16_15_17_Pro.jpg
WP_20170324_16_15_24_Pro.jpg
WP_20170324_16_15_28_Pro.jpg
WP_20170324_16_15_34_Pro.jpg
WP_20170324_16_15_46_Pro.jpg
WP_20170324_16_15_51_Pro.jpg
WP_20170322_17_22_24_Pro.jpg
 
Last edited:
There's lots about this job I don't like , first thing is the ceiling should be up before floating so that the ceiling sits on top of the newly floated walls, also as mentioned above sounds like he don't want to float or can't, also even though it's a scratch coat the corners are cr@p it's making it hard to float them in straight being not level or straight like that , things such as limelite was made for this kind of situation ,supposed to mimmick render why would that invalidate the guarantee? Have all the scratch coat got wp in it? Anyone can do a scratch coat that's the easy part but should be done better if your going to get it right
 
Sponsored Links
Just to add it won't be the bricks cracking your plaster it will be his lack of knowledge also seems like u have had dp done and doing your own render? You may have well have done the lot why pay someone to inject a few holes?
 
There's lots about this job I don't like , first thing is the ceiling should be up before floating so that the ceiling sits on top of the newly floated walls, also as mentioned above sounds like he don't want to float or can't, also even though it's a scratch coat the corners are cr@p it's making it hard to float them in straight being not level or straight like that , things such as limelite was made for this kind of situation ,supposed to mimmick render why would that invalidate the guarantee? Have all the scratch coat got wp in it? Anyone can do a scratch coat that's the easy part but should be done better if your going to get it right
Thanks for your reply stevethespreader

Yes all should have waterproofer in (although only half a 5l tub seemed to be used? Not sure if that sounds about right). The two main damp injection companies here both insisted on s&c if any claim was made in the future they wouldn't pay for remedial work if anything other than s&c was used. This was when they were asked about limelite.

Starting to sound like I should be looking for a new plasterer...
 
Just to add it won't be the bricks cracking your plaster it will be his lack of knowledge also seems like u have had dp done and doing your own render? You may have well have done the lot why pay someone to inject a few holes?
Definitely haven't done this myself!

The injection was only 300 which I thought was worth it for a guarantee.
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Back
Top