Leaving render unpainted over winter?

[Titsywoo]

We built a new single storey extension this year. It was rendered a couple of months ago with waterproof render but we were advised to paint to provide extra protection.

The problem is we are doing the internal works ourselves and it looks like we won't have time to paint until the spring. We can't afford to pay someone to do it. It will take couple of days as it needs stabilising solution applied first and it is a big extension.

So my question is will it be ok to wait another 6 months? Even if we have another wet winter?

Thanks :)

I'm sure it will be OK. If rendered, it will be no more water-absorbent than a plain brick wall. As it is new I presume it is a cavity wall so it will not easily allow damp to pass into a heated room. Good gutters will keep a lot of the rain off.

BTW I would have used a couple of diluted mist coats, applied with a brush, rather than stabilising solution. Don't use PVA glue which is water soluble.

If you have differing advice, ask the paint manufacturer.

We are using a latex based paint so we're advised to use stabilising solution for that. Bought it now anyway! There is one dark patch on a corner where water seemed to be pouring down before the gutters went on and a roof issue was fixed. Not coming through. Yes it's a cavity wall with celotex in the cavity. Glad it will be ok though. Was panicking a bit!

Sorry forgot to say thanks

'Waterproof' render, eurggh.

Cement/Concrete is naturally waterproof, so I wouldn't worry about it being unpainted at all.

Be more worried about if you get cracks later on, which will let rain in, but it won't be able to evaporate out, leading to damp walls.

Ok thanks. How long generally until it starts to crack? It was rendered about 4 weeks after the shell was complete so most of the initial large movement was over at that point.

old lime render tends to loosen and scab off after 50-100 years, but a modern cement render should not crack significantly unless the wall is moving. Hairline shrinkage cracks are not significant.

Ok well hopefully that will be fine although the extension will probably still be moving since it is new for a while I assume?

Anyway we have no time to do it so we will just have to pray it is ok - was just hoping to put my mind at rest a bit :)

modern building uses much deeper and stronger foundations than Victorian houses, so the wall should not settle and crack. You may however get a crack where the extension meets the old house, because they will be on different foundations. This will be the joint, not the wall, cracking.