Cracks in render ?
- Thread starter Spray
- Start date
Spray
Well-Known Member
Sounds like your pissed off mate with the rendering game
Spray
Well-Known Member
Nope but that’s not the question lol ?
Lol
beader
Private Member
No and guess what....but not all the time.Tbf.
essexandy
The Lake Governor
I worked on the same basic eight designs of house for fifteen years. Now unusually in this day and age the builder didn't rush things along and the blockwork had often bee stood for twelve months or more before I rendered/plastered them. It didn't take too long to get to know exactly where cracks would appear on certain house types. Initially I would paper and EML over the cracks and later on started to use fibreglass mesh embedded in the scratchcoat. The cracks never came back through using paper/EML but did on a couple using the fibreglass mesh. Obviously I dropped the fibreglass mesh and carried on using paper/EML.
I wouldnt dare not tbh
beader
Private Member
It depends on what you call back in the day?.When I started in 86 it was not available to my knowledge but others may know different.
an area to be rendered would be built with keyed bricks,laid on a bed of lime mortar, as these are now to expensive , it is all block work, built with a strong mix of sand and cement.
essexandy
The Lake Governor
We rendered a couple of sites on fluted flettons and there never seemed to be any cracking, and they were laid with S&C.
when we was NHBC registered ,we often received advice to use keyed flattens and add lime to the mortar to receive render.
we have stripped new properties of their render and redone for the NHBC. these were often on lightweight blocks.
essexandy
The Lake Governor
Well you know as well as I that people struggle to work with lightweight blocks Malc. And that's brickies as much as spreads. Muck is usually way to strong.
vfr12
MOTORC*NT
Only in uk they are laid on with s&c and the strength of the mortar has nothing to do with this, it’s the suction they can’t overcome. Any other country in the world uses special adhesive, apart from Africa maybe .
The Hobo
Well-Known Member
mud
The Hobo
Well-Known Member
sorry u disagree andy but seen to many fck ups not mine don't do it
essexandy
The Lake Governor
I've done many many S&C renders over a variety of substrates and much prefer it to bagged materials.
The Hobo
Well-Known Member
cant comment never done bagged gear mainly a Victorian internal man / if u ever up my way give u a few days free fishing pike and course
essexandy
The Lake Governor
Cheers Norman, you never know I might just make the journey.
Danny
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essexandy
The Lake Governor
That wasn't why we were laughing at you mate.people laughed at me when I have said that in the past
essexandy
The Lake Governor
Yeah I have seen the adhesive used locally a couple of times.
Overstrength brickies muck does cause lots of cracking. I remember a builder sending a sample of the local sand off to the manufacturer of Durox blocks and they recommended a 16:1 mix be used.
The Hobo
Well-Known Member
think your right pal local sand is a big issue brought up in Lancashire work in isle of man for years been in Scotland last 35 sand is a big issue back in lancs on site work seen thermo walls split to fck cuase gear to strong
beader
Private Member
4.1 mix will crack light weight blocks straight down a wall .But you can't explain to bricklayers. It's the same principle as render that the mix must be weaker than the substrate to be covered.
Arti
Well-Known Member
16:1 holyshit balls that's weak
essexandy
The Lake Governor
Yeah that sand goes rock hard at 10:1, literally a job to tidy up your internals before skimming.
Rigsby
TPF Special Forces
At first sight, it is presumed the applicator has got it wrong somewhere but that is not always the case.
The substrate can be wrong for example, the blocks have just been laid, wrong strength. But also structural cracking. I have seen plenty of that.
Weak blocks can be overcome but that's if we know. Concrete blocks look like concrete blocks, how are to know what strength they are? Then there is the ignorance of the client being told but they ignore your advice and you get told to get on with it.
As for applicator error? Yes, that is possible. base coats not cured enough, rendering tight up to expandable surfaces like soffits and frames. Wrong materials on the substrate like for example, Mono on cement particle board.
But when a crack happens and it is not obvious why then it is easy to blame the applicator and hold back payment. Unless the applicator can prove his innocence, then he is deemed guilty. A bigger problem is when the applicator knows what caused the problem and he is not believed. That is when the s**t hits the fan!
Spray
Well-Known Member
Back in the day I think build quality was far higher mate
Spray
Well-Known Member
correct mate
Spray
Well-Known Member
Agree Jon !