Repairing holes in rendered wall

[Justine Time]

Am considering wall insulation. The sponge finished rendering is 3 year old and freshly painted 1 month ago and in excellent condition. Would you trust the installers to fill the holes to match the rest of the wall. I was thinking maybe to ask them not to make it flush with the wall and then I would come along and do my own mix and filling (carefully). Would I need to know the exact grade of sand the renderer used and what sort of sponge he used.I don't want to have any scars/shadows as to where it was plugged.

What do you reckon guys.

[Man at B&Q]

[stuart noble]

I reckon you'll be lucky to achieve a perfect match, not least because the mix used for the render may not work as a shallow filler. You could do worse than dose a normal sand/cement mix with pva and finish with a dry washing up type sponge. IME knowing how long to leave it before using the sponge is the difficult bit. Not too wet, not too dry etc.

[Tabby]

Installers tend to make a dogs dinner of this bit. Really if you've no idea how to get a matching finish, its unlikely you will.

NT

[Owain]

most of them ;-(

Agreed.

But if you've got spare paint it should end up a similar colour, if not shade and texture.

Owain

[Justine Time]

In that case I would be prepared to pay the guy who did the rendering to do it, but then, even though he has been in the business a million years or so it could be difficult/impossible for him to achieve a perfect finish.I will contact him. I would sooner go without insulation than have patches all over the walls. Thanks guys

[Andrew Gabriel]

It's impossible, even if he used the same mix the next day.

What about injection from the inside? That's probably easier to repair invisibly.

[Tabby]

Absolutely. Not hard to get a good filled finish. Another option is to skim the outside after its done, with cement mix.

NT