Rendering. PLEASE HELP
- Thread starter G2607
- Start date
Ok
Back to basics first
Sand is the aggregate (won't stick to itself or anything else - without........)
Binders
Cement and lime are binders (bind s**t together and stick)
You have more in the 2nd than 1st coat, hence it's stronger (and heavier) which leads to.......
Your predicament.......
To much 'weight' (and strength) over a more feeble base.
You can adjust, and it'll be fine.
.
Stay with 1st coat (I'd add fibres myself though)
2nd - go 8 to ¼ to 1 (and fibres again (small ones))
Salfordspread
Member
Ŵe used to add fbres in the scratch coat many moons ago before good old ocr came along . That's a proper old school trick that is that only a few of us old dinasors use .Stay with 1st coat (I'd add fibres myself though)
2nd - go 8 to ¼ to 1 (and fibres again (small ones))
Salfordspread
Member
These we used to get when the dreaded bell mixer raised its ugly head
That's them, although we changed to 6mm
Found 20's could sometimes pop up "out" on warm days rubbing up.
I carry 2mm , 6mm and 8mm fibres now.
Don't even see them.
Work well though, knit it tight.
essexandy
The Lake Governor
I reckon the original Fibremesh (?) brand used to be 40mm long. Finer than a human hair and never had any problems with them. In fact they were way better than the modern clumpy crap that's available now.That's them, although we changed to 6mm
Found 20's could sometimes pop up "out" on warm days rubbing up.
I carry 2mm , 6mm and 8mm fibres now.
Don't even see them.
Work well though, knit it tight.
Salfordspread
Member
Fibre mesh that's the stuff been a long time since we used them tbh
essexandy
The Lake Governor
I used to buy it from a local ready mixed concrete company up to about 2004. Definitely the best one that has ever been available. A quick stir into your mixing water and the fibres completely separated, never a single clump of them. I used them for both screeding and rendering.
Salfordspread
Member
Showing are age now . Ha ha
I think that's the difference between fibreglass and polypropylene fibres.
We used to get proper fibreglass that would separate equally/evenly through the water first, you stick polypropylene ones in there and it looks like frogspawn
Probably cheap Chinese shite flooding the place again?
essexandy
The Lake Governor
Possibly, but I thought the original ones were polymer fibres not fibreglass?
essexandy
The Lake Governor
Yes mate I did and do, mainly because that's what the manufacturers called them.
essexandy
The Lake Governor
Not the good ones, haven't been able to find them in years.
Still use the crappy ones in both screed and rendering.
Monkey Boy
Well-Known Member
Go to bed
essexandy
The Lake Governor
The fibres I first bought were made for the concrete industry you thick c**t. They work in two ways. Millions of fibres criss crossing in the mix give added strength (hence why fibres are spec'ed for screening in place of steel mesh for most applications) and if cracks do form they follow the paths of the individual fibres, meaning that the cracks are ultra fine and usually invisible to the naked eye.
Salfordspread
Member
Same applies to the hairs in lime . Ha ha there's some M T HEADS on this here forum alright
algeeman
It’s A Boy
algeeman
It’s A Boy
but lime still cracks aswell
Monkey Boy
Well-Known Member
I think the large aggregate in concrete acts like type 1 MOT subbase and all the stones play off each other giving great resistance
Cockney
Well-Known Member
Go to bed!
essexandy
The Lake Governor
Same reason screed still cracks with steel mesh embedded mate. Outside forces. Rendering will be for a multitude of different reasons. All you can do is take as many precautions as possible.
You'll know as well as I do that on site the same plot types will have cracks in the same place, that's got to be down to design, hasn't it?
Salfordspread
Member
Yes till the top coat goes on that's why it's sprayed down as much as possible . No material contained water is guaranteed not to crack
Danny
-
You have to press the 3 dots
algeeman
It’s A Boy
essexandy
The Lake Governor
My house is to calm mate, his little head would implode.
You don't have any of these
how odd, ya c**t.