Patching up this render

[CzDuck]

Hi all,

We're currently in the process of preparing our 1877 mid-terrace for sale in order to up-size (and fast forward 56 years to 1933). Over the last 7 years we have done a complete overhaul of the inside, but not touched the outside other than replacing doors and windows.

The outside of the property is rendered and painted and in quite a number of areas the render is blown or has completely fallen off. We want to, at least, patch up the bits which have fallen off in order to tidy the house up. Of particular concern is the wall which runs down the alleyway between the properties.

I've attached some photos, and as you'll see there seems to have been a number of layers of render over the years. What I'm hoping someone here will be able to guide on is what would be the best thing we should be using to patch up the worst of it.

The walls themselves appear to be either solid brick or very early cavity (ie. not functional as a cavity, really) but we have never had damp problems even though, based on what we found inside, we suspect the outside hasn't been treated 'traditionally'.

This area specifically is actually undercover -- it's a passageway through to the back gardens which our 1st floor runs over -- if that makes any difference or life any easier!

Thanks in advance for your suggestions and advice!

 

[Zebra]

Hmm. Can't tell if that render is lime with a traditional limewash or, as I suspect, cement with masonry paint. It's probably too thin to be lime, isn't it? Wonder why it's failed there. Looks like there was an earlier cement render which has been scraped off in order to apply whatever then failed, so it may not be the first time this area has been re-treated. I think if it were me I would be looking to apply a lime render and limewash but I appreciate it's a very small area to be buying in materials that you wouldn't otherwise have or use. Have you got any lime products left over from your interior works, or have you renovated the interior using modern materials?

 

[CzDuck]

Thanks Zebra. I agree it seems too thin to be lime render. It certainly doesn't seem to be the three layers I'd expect to see on a lime render (assuming you would apply it the same way as a lime plaster?).

There is another patch on the same section of wall where the top coating has come away and what is underneath seems to me to be more cement-like, although a very light colour. It certainly seems harder than I would expect for lime. It also seems to have more coarse material mixed into it. Photo attached.

I'm not sure if the front of the house is rendered the same way or at the same time, but there is a section here where the top coating has come away where it joins the neighbouring property and what is under that also seems to me very likely to be cement, and much grayer than on the side wall (although is that possibly an old coating which has just been painted over?).

I'll have a look at what we have left from inside. We have made repairs with lime in places (although thankfully few), but I know from removing the covering on the inside of the vent you can see below the damage in the above photos, the internal side of this wall has been plastered with multifinish before our time. Again, there are no damp problems here.

Thanks again!