New render on the house is cracked already

[WabbitPoo]

Had someone out today to render around a window (as it has blown). I get home to find him gone and there are crackes all over the render already. As they are due to return some time soon to do the trolean render finish, I need to know the likely cause of the cracks before I ring them to complain.

Is the most likely cause that it dried out too quickly on this warm day?

Either way, its gonna have to be redone.

 

[roughcaster]

Probably dried out too quicky. Get them back anyway WP,,, it's no good working onto a surface that's cracked before you start.

 

[WabbitPoo]

For those who are interested, here's some pics of the bodge.....

I can move the "chunks" between the cracks by pressing them with my thumb. Woeful

 

[crank39]

Were they planning on coming back to tyrolean it or is that it?

 

[roughcaster]

For God's sake,,, what a really awful mess. It looks more like mosaic than render. That is a write off Poo,,, no doubt about it. All of that render needs to be removed that's for sure. DID THEY SCRATCH COAT IT FIRST, OR DID THEY BRING IT OUT IN ONE THICK COAT?? There is no way you can save that mess. I think the problem with your job would have been high suction on the wall itself,,, probably not wet down enough in the first place. You would get the same cracked effect with plaster etc, if you coated it straight onto say, thermalite,, red brick,, etc. Preparation of any surface before you plaster or render is paramount. High suction is as bad as heat/wind/draught, when it comes to quick drying.
If they had given the wall a "good soak" first,, scratch coated it with a waterproofer/plasticiser in the scratch coat, leave to dry and cure for a day or two,, then wet the wall again, then render,, you would have had no problem. In my opinion though,, it's dried out far too quick, causing it to shrink and split.

 

[WabbitPoo]

I was not present, but it must have been one coat. They arrived when I wasn't here, having not told me they were coming, so peeing off the old crone who's garden this window overlooks. Looks like she's gonna get peed off again when I get them back to do it all again!

 

[roughcaster]

Right enough WP,,, if the render was finished when you came home later that day, it would prove it was done in one thick coat. That's why it has dried in and split. If it was done in two coats,, (scratch and top),, with the right prep, on two seperate days, you would not have the problem. Tell them that,,, although they should know!!!

 

[stuart45]

Did the same thing when I was a teen many years ago using a strong mix and one coat. I got exactly the same finish. My rendering isn't much better all these years on.

 

[roughcaster]

Can't be as bad as that though Stu'.

 

[marshman]

Well that's a good example of shrinkage cracks, that might be soft sand as well, its got to come off and be done again.
I agree with rc on the cause.