How to proceed? - any advice welcome!

[Stainless]

We've just bought a semi-detached, cavity walled, 1930's ex Local Authority house which at some time has had a porch poorly built and poorly removed at the rear of the property. The poor construction has let water penetrate behind the render and caused large areas of it to blow which in turn has caused areas of the internal walls to become damp, flaking paint, etc. (and also the fact someone has rendered over the damp proof course). The side wall and front walls don't seem too bad, it's just mainly the rear.

I'm fairly sure that the render is original as a number of houses in the local vicinity, including our next door neighbour have exactly the same type of render and finish. I'm also fairly sure that it is a sand/cement render, hence the reason it is trapping water.

The blown render has been removed and the internal walls are already noticeably less damp.

My first question is what is best to replace the now missing render with? I am reluctant to use a cement render as I can see the same problem of damp internal walls coming back. I'm guessing a Lime render would be the way to go to allow the walls to breathe? If so what mix ratio is recommended?

My second question is how do I re-create the original textured finish? (two photos are attached) so that the rear of the house blends in with the house next door and also our own front and side walls. Again, I would guess at a textured roller of some description?

Many thanks!

 

[Rigsby]

It looks painted? If you use a lime render then wont you lose the breathability by painting it to match?

It looks to me to be a fatty cement render and the stipple today could be created by a sponge in a plastic bag. Getting it to match perfectly will not happen. The man that did it will have took his method to the grave with him. You would need his tool, same mix and conditions. But it could be close.

 

[malc]

there was an exterior artex.
we use to put an empty mastic tube on a paint roller to produce a light stipple finish. if this is what the finish is.

 

[Spoon]

That was called sandtex I think you are talking about. Used that back in the early 90's. Don't think it would work well with lime though.

 

[tam]

That looks to me that it might be napped. Which is sand and cement floated as normal then when firm, wet with a brush and float with a sponge float to bring a fat on it, then dab it with the sponge float. Hope this helps.

 

[essexandy]

I think Malc is on about Hibuild, which is what I thought that finish looked like straight away.

 

[DannyMac]

I don't think that is finished with a roller. Looks more like it's been patted with a sponge in a plastic bag.

 

[Stainless]

Thanks for the replies. I shall try a small test section with a bagged sponge to see how it works out.