Hairline cracks in render

[mickthejig]

Hi guys, first-time posting. My name is Mike. Carpenter by trade, but can turn my hand to most things, and I'm doing a large self-build extension. The extension is concrete block with render. Up to now I have rendered 3 large walls with no problems. Over the weekend I rendered the front elevation which is now showing lots of hairline cracks. As far as I can tell I have done nothing different. I have used a 4-1 plus waterproof-er for the scratchcoat and a 6-1-1 for the top coat. The only thing I can think of is that when I put the scratch coat on it turned into a very wet day before I had finished - could this have made a difference? As the wall was not well protected. Any ideas what could have caused this, and as we will be painting the render will the hairline cracks show after painting?

 

[johniosaif]

Possibly dried too fast, itmaywell be hidden by the paint,otherwise you may need To go over it with silver sand with an sbr scud prior to this,

 

[church]

just go brickwork in future , we all live and learn

 

[irish_spread]

Sure it wasn't breeze blocks ?

 

[church]

Sure it wasn't breeze blocks ?

its ninus ******* around mate , ask yourself what type of dope builds in breeze blocks these days

 

[Rigsby]

Did the render get very wet? Also if so did it dry quickly? Did you put the same amount of lime in and any plasticiser?

 

[plastererpeter]

Did u gauge out material

 

[johniosaif]

its ninus ******* around mate , ask yourself what type of dope builds in breeze blocks these days

Did an extension last week,all thermalites. Used red grit then ocr, turned out nice enoughnice enough

 

[Rigsby]

Did an extension last week,all thermalites. Used red grit then ocr, turned out nice enoughnice enough

You would have, you had suction control.

 

[church]

Did the render get very wet? Also if so did it dry quickly? Did you put the same amount of lime in and any plasticiser?

just give up mate , i have :RpS_bored: