How to repair crack in thin coat render on EWI

[SimonD]

I clearly must have had a moment when I did my rendering on the EWI as I've just noticed cracks in two corners around my front door frame. Clearly, forgot to detail the mesh correctly, or even put it in place. Can someone advise on the best method of fixing this? How much of an area do I need to take off to add mesh and how do I blend the repair in to the existing?

[Redbeard]

Do you have pics? Is this on the reveal? If so my suggestion of scraping back 150mm might not work as there may not be 150mm of reveal! But if you have the space, chop back (say around 150) till you find the mesh (and then you'll also see where it isn't), thin toothed coat of base-coat, mesh in, thin coat over, and try to recess about 1-2mm (depending on top-coat grain size (if indeed you have top-coated with 'from-a-bucket' stuff). This is what I have done. You *will* see the join at least a bit unless you are very lucky, but after a while you will have other things to look at.

[SimonD]

1 hour ago, Redbeard said:

Do you have pics? Is this on the reveal? If so my suggestion of scraping back 150mm might not work as there may not be 150mm of reveal!

 

Thanks, yes, it's on the reveal and I don't have 150mm. Pics below.

 

Also come to think of it, I've got a very thin length of ewi at the top of the doorset and sidelights. I'm wondering whether this has contributed the issue as it's a big heavy door, it's on a timber frame and the ewi is thin along the top so not much area to reinforce with the mesh. There's probably a lot of potential movement, and it seems it's only appeard following the very cold snap immediately followed by warm wet weather. (and yes, before anyone says anything, I do need to tide up the render on the door frame 😁)