K Rend Hairline cracks

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Munners

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Alright lads new to this forum business. Got a fair size KRend job which is split into 6 panels. Each panels been sbr'd onto the brickwork followed by a backing coat then a top in pewter grey. The problem is when we come back 12 hours later to rub up there's a few hairline cracks in different places over the panel. Anyone got any ideas? Cheers Munners
 
Are you sure its hairline cracks ?

when hand applied this can appear like a crack but its more like when the gear slumps and seprates - happens with hand apply on this gear as its not the best at binding together, very gritty, not enough good stuff.

you did say it was before you rub up ?
 
Na mate just straight forward KRend backing coat?

It has been applied by hand, rubbed up this morning and the cracks are still there. KRend weren't very helpful on the phone they just said fill in the cracks with the dust from the scratch and fill it in with that. Which I've tried and it just falls out again soon as anyone touches it.

The labourer was knocking it up, leaving it 5 minutes or so then knocking it back up again.

from having a look around the forum the only other thing I can think is that sbr wasn't the best thing to put on the brickwork? I saw a post that said that sbr on the brickwork before putting on the backing will cause the backing to suck the top and cause cracking?

What do you fellas think? Cheers for the help.
 
No mate straight forward KRend backing coat.

The KRend was applied by hand but rubbed up earlier and the cracks are still their? Spoke to KRend on the phone and all they said was that to fill the cracks use the dust from the scratch which I tried and it didn't really help because its still noticeable and as soon as anyone touches it, it all falls out.

Got the labourer knocking it up and leaving it 5 minutes then knocking it up again. KRend say it takes 10 minutes for the particles to desolve properly.

Looking around the forum the only other thing I can find is someone's posted that if you sbr the brickwork it causes the backing coat to s u c k the top coat? Anyone got any views on that?? Cheers for the help lads.
 
I've noticed this before in the day we use to hand apply, for what its worth i don't think its suction issues but caused by trapped air(air pocket, bubbles) from the laying down, probably from inconsistent mixing and from laying in to drier/wetter gear. Its more common in my experience with one coat application rather than the preferred two coat.
 
using parex and now weber regularly spraying.....picked up a couple of bags of krend from local selco just to get a head start on some beading before gear arrived. omfg what sheizer.....dead, crude, slumpy, slidey. I've said it before but this stuff is the coloured render equivalent of cpi gp mortar.....cheap & not so cheerful. When the pral m arrived hallelujah......
 
The difference is amazing in quality I agree.for k rend to suggest to fill cracks in with dust, just about sums them up.
 
it wouldnt be the sbr mate defo, sounds like technique/mixing or something along them lines. Is it gone on quite heavy and sagged or cracking along a mortar joint pal? Fill in with dust lol krend should no better than to tell u that, tut tut...
 
mix up some gear late evening bang it in the fridge overnight. next morning take it to the job break it up and use this stuff to overfill fill the cracks. then rub em back with a small piece of nailfloat
 
Hi mate, try using a serrated rule to get rid of the air pockets. I would also apply in two passers, I would put a coat on up to about 5 meters then second coat it. As if the first has pulled in to much when you apply second pass. When it comes to scraping you could scratch threw which will cause haloing and looks like a dogs dick. Hope this helps
 
it would be great if Krend just changed the gear to cover a metre Square per bag and made it more user friendly for those that tend to have problems. there is deffo more people complaining about krend than any other product
 
I agree, with the good placement they have in the market...shame the product has been left behind. All they need is to tweak the formula(copy weber, Parex) and change the bags so that it has a relaunch and hey presto....lots of Krend being used and praised. Doesn't the boss of Krend care at all about a duff reputation or is he just coasting to retirement or summat?!?
 
Hi Im new to this forum. Our house was done with k rend last year by a plasterer in August and has started to show a few hairline cracks. These cracks have only come out now since the warm weather in the last few weeks. It is not hollow at all. Two cracks are coming from both corners of a window cill. Are these cracks settlement? Then there are a few more hairline cracks on there own. Also there is a crack where two walls meet at a 90 degree angle. There is also one long back wall with no expansion joint in the plastering and it is around 6- 7m long with mostly sliding doors and glass. This is where all of the cracks are. These are not bad at all but why are they coming out now. I cant get the plasterer to come back at all. The k rend was silicone based and sprayed on. There was a scud coat and then a base coat of 3-1 sand and cement with water proofer. Then it was sprayed on with a machine. Any suggestions or help ?
 
Alot of renders crack even if you go by the book, there's always someone saying he should of done that etc
 
biggy said:
Hi Im new to this forum. Our house was done with k rend last year by a plasterer in August and has started to show a few hairline cracks. These cracks have only come out now since the warm weather in the last few weeks. It is not hollow at all. Two cracks are coming from both corners of a window cill. Are these cracks settlement? Then there are a few more hairline cracks on there own. Also there is a crack where two walls meet at a 90 degree angle. There is also one long back wall with no expansion joint in the plastering and it is around 6- 7m long with mostly sliding doors and glass. This is where all of the cracks are. These are not bad at all but why are they coming out now. I cant get the plasterer to come back at all. The k rend was silicone based and sprayed on. There was a scud coat and then a base coat of 3-1 sand and cement with water proofer. Then it was sprayed on with a machine. Any suggestions or help ?
Click to expand...

Just has this on a job completed 8wks ago, the hot weather in the last week has caused shrinkage to a random nature. Hacked off a section to see if base coat had cracked, but it is sound and solid. Job was rendaided, riblathed, cloth meshed and scratched over old s&c pointed stone work, topped with egrade(sprayed)

I reckon its the stonework building up thermal mass and releasing it quickly through the weaker topcoat in the cooler evenings. We're getting this confirmed later in the week.....will keep you posted.
 
Cracks from the window sill ends sound like stress cracks. Well the stress is not down to the renderer but he should have put decent size stress patches in and left an expansion gap around the window sill. If the render is tight up and the sill expands in the sun then something has to give.
 
Sound lads thanks for that. So basically it is movement around the window cills and expansion etc and it wasn't meshed in the base coat is the problem and no expansion joints. Thanks for your help lads. I presume there is nothing can be done unless it is all re-done as I know K rend cant be repaired/patched. Thanks for all yer help lads
 
If I remember rightly, there is a product called MENDREND on the market. Even though I havent used it,the manufacturers claim that its a resin based product,applied through a syringe and can be tinted to any render colour,leaving an invisible repair.:huh:
 
22jasper said:
Just has this on a job completed 8wks ago, the hot weather in the last week has caused shrinkage to a random nature. Hacked off a section to see if base coat had cracked, but it is sound and solid. Job was rendaided, riblathed, cloth meshed and scratched over old s&c pointed stone work, topped with egrade(sprayed)

I reckon its the stonework building up thermal mass and releasing it quickly through the weaker topcoat in the cooler evenings. We're getting this confirmed later in the week.....will keep you posted.
Click to expand...

i would guess that the riblath has expanded in the heat and cracked the render.
 
Sounds like you want to put the blame on the spread!! About right!! If its been on there a year before it cracked then its structural. You only need to put expansion beads where there are expansion joints and you bead under cills etc to allow for movement on timber framed builds. Mesh to stress points is fair enough but down internal angles?! Some jobs require full mesh but without knowing the substrate and build how can anyone commenting know it needed a full mesh?
 
And mesh doesn't always stop cracking. I've had jobs that have cracked and we've done everything by the book and its cracked and we've had to dig out the render and prove that it's meshed and the client still thinks its down to us!
 
Rigsby said:
Cracks from the window sill ends sound like stress cracks. Well the stress is not down to the renderer but he should have put decent size stress patches in and left an expansion gap around the window sill. If the render is tight up and the sill expands in the sun then something has to give.
Click to expand...

Do you use stop beads around the cills or form a soft joint using foam to allow for expansion?
 
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