Need some help lads

Status
Not open for further replies.
M

mshawplastering

Member
Hi lads
Had some damp proofing done in a house that we are working in we have job of s&c on the lower half of the wall the speck says 10mm with water proofed 3/1 10mm at 4/1 and 5mm skim the prob is that after hacking off the wall at 1mtr the plaster is only about 8mm all over been told to 10mm water proof then cover the hole wall with s&c 4/1 then skim thing is we done the window wall today and the s&c was sliding all over the place we did key the wall before we started can't hack anymore off the walls so how do we stop the s&c from sliding around would WBA do the job
 
Sbr slurry that would b 1.1.1 with cement and sharp sand then brushed on left till dry or would u leave till tacky before you go on it with s.c
 
Last edited:
Hi lads

Got mix wrong on sbr it should b 1/1 sbr and water and then 4/1 protland cement the only thing am not sure about is do u wait till its dry then start to render or when it's sticky to start rendering on to it any help will b great many thanks lads
 
Why not just float to match existing with 3-1 s+c with waterproofer in 1 coat. Then skim when set. I know its not to spec but what can you do, the spec is thicker than what your matching to.

You cant make the bottom half the wall thinker as any door linings/architraves, rads, skirting, sockets and ever the carpet won't fit back.

Failing all the above get advice off of the DPC firm.
 
As Carlos says get advice from the DPC company but if thats what they stipulate in the spec it sounds like you gonna have to do the whole wall so its all the same thickness
 
Hi lads did get advice from dpc company and that is there spec not mine and that is what that are telling us to do did say I was going to float hole wall in s/c that's why I had probs as could not get s/c to stick to the wall that's why I was asking and spr slurry as for rads that's down to Plummer the skirting that's in the bin as was rotten things plugs just use longer screws like said this is the dpc company's job not mine and its there speck not mine I just wanted to find out how to stop the s/c from sliding around and get it to stick that's it
 
What are you rendering over for it to be sliding around??????

If its painted brick you should be hacking it up provide a key.

If you trying to render over the existing plaster above 1m then, no wonder your having trouble.

Or have I got this all wrong????
 
hi carlos
like i said its on the walls on the in side and yes it was cut up to make a key with an angle grinder and it was going on at 10mm so yes it would of slid around as it did the reason for the thread was to ask for help with sbr or some thing to help with a key to stop it sliding and thats it and yes the top skim will only b 2/3mm max as standed on a reskim
 
So the thickness of the S&C on the existing is 8mm? And they want a total of 25mm? How about S&C with waterproofer where knocked off then dot & dab over the whole lot with 3/8" MR boards? Damp will only rise so far due to capillary action hence only 3' is knocked off. In my mind if you're wanting to render the whole wall then all the old backing needs to knocked off back to brick/block. I wouldn't put new over old as there's more chance of it shelling off with the extra weight and deterioration in the old render.
Well that's my crazy thoughts on it anyways.
 
I see, in which case SBR mix 1:1 with water then add OPC and whisk up till like double cream. Its 1:1:4 water SBR OPC.

Brush on and render straight away. If you let it go off it will be waterproof like a cement tanking and you will be back to having the render sliding round.
 
i think that the damp proofe com. has not got a clue.
if the whole wall needs to be plastered then it all must be stripped back to brickwork.
 
Status
Not open for further replies.
Back
Top