Loose render - how do I fix?

[pcornall]

We bought our house last year and I've been getting ready to paint it by snapping off peeling paint and sanding down, etc. (The old owners used cheap paint).

However, on one part of the wall when I took off some of the old paint, part of the top layer of render came off (about 20cm x 15cm). Underneath is another older layer of render that feels very solid. Around the edges where the render came off, I can feel the top layer is not stuck down and loose, leaving a slight gap which is obviously a concern if moisture was to get it. It also looks weird as the two types of render have different textures.

Does anyone have any recommendations on how I should fix this? I'm guessing I need to seal the gaps around the edges with some sort of sealant or adhesive, but I don't know what. I'm also not sure if I should use some kind of external filler to go over the area so it is flush with the rest of the render (it is a lumpy style of render so wouldn't need to be too pretty).

 

[vinn]

A photo would help me.
Maybe your old paint is a plastic paint, perhaps your old paint, wont allow moisture from the house to get out, and any water thats got behind any damage or cracks cant get out either. So eventually the render begins to blow.
Depending on the extent of the damage and the difficulty of removing the old paint its sometimes worth hacking off, and re-doing the render with the modern stuff, or even external insulation and render.

What did the mortgage surveyor have to say about the render?

 

[pcornall]

Sorry, here's a photo attached. The survey didn't raise any issues with the render. The paint was Wickes bog-standard own brand (found old paint pots in shed!). Apparently it was only painted about 3 years ago, but not sure how old the top layer of render is. Is it going to be a case of having to remove all the blown render and then re-render?

 

[vinn]

The only paint fit for render is top quality masonry paint.

Judging by the photo, it might be a worst case of removing all your render back to masonry and beginning again.
But first continue lifting off until it all comes off or you reach solid attachments to the background.
I would remove all the surface layers anyway because, unfortunately, solid seeming backgrounds are covered for reasons - maybe crazing or movement cracks.

It was possibly painted pre-sale for the sale, and the usual so what RICS mortgage Surveyor was fooled by appearances.

 

[pcornall]

No worries - thanks for the advice. I did wonder why the new render when the old stuff seems very sturdy... I do wonder what the point of a survey is, as I'm sure do most other people.

I'll take off all the loose, blown render and see how big an area I'm left with. If it grows big I'll get a pro to deal with/advise.

Thanks a lot.

 

[stevethespreader]

Looks like textured paint to me that's peeling off with a solid render background