Peeling Paint On New Lime Render

[JROBNO24]

Hello Everyone,

About a year ago, we had the entire outside of the house re-rendered to replace the cement base render with a lime base render. The house is a late Victorian build (1880s) with no damp proof lining.

The rendering was finished around March and painted soon after. Beeck Renosil Fine Mineral Paint (suitable for lime render) was then used after applying a Beeck Fixative first.

Since then the paint has slowly been peeling off on all the walls that face south west (where most of our weather comes from). These walls are now just a mottled, patchy, cracked mess (see pictures). I can confirm that the render itself is still solid and not shot. There are a couple of small hairline cracks in the render, but otherwise the rest of the cracking is in the paint work.


I reached out to the supplier of the paint to try and find what's going on. I knew lime would be hard work, but I didn't expect this to happen on such a scale so soon. They suggested, I remove the paint and then repaint with a coarser Beeck Mineral paint first to fill the hairline cracks, and then paint with the finer Beeck mineral paint that was originally used. However, what they haven't told me, and what I'd like to ask here is:

- Why has the paint not stuck, like it has on the North Eastern facing walls?

- How do you remove paint off of the lime render without damaging the render?

- Do I have to apply the Beeck Fixative for both the coarse paint layer and then the finer paint layer?

Any insights would be gratefully appreciated.

Cheers

 

[larry]

Weird, I thought silicate paint was supposed to bond with the masonry... Which doesn't look like has happened. Was there some 'weather' soon after application? Was the base coat definitely applied? Basically just asking questions, my only experience is we used silicate paint for our own house, and haven't had any problems.

 

[stuart45]

Was the paintwork done by you or a contractor?

 

[WiltshireBoy]

Why has the paint not stuck, like it has on the North Eastern facing walls?

I think you might have answered you own question when you mention the wall faces south west from where most of your weather comes from. I'd suspect it's not the 'weather' per se but the heat from the sun. A south west facing wall pretty much gets the sun most of the day making it perfect for heat absorption, and you would be surprised how hot it does get (& remains). In contrast a north east facing wall pretty much gets no sun at all.

As to the resolution - i'll leave that to the more knowledgeable.

 

[Robola]

How soon after rendering was it painted?

I painted a wall of our house last year with silicate paint - over a combination of new lime render, the existing old render, pointing around the windows. It is South East facing and also very exposed to the sea. The only place that it has done something similar is an area of pointing that maybe hadn't fully cured when painted.

There is also an old church near us that was painted in silicate paint, the main part of the building is fine but the bell tower has completely failed. It looks like the render had a fine dusty layer on the surface that the paint had adhered to. The dusty surface layer of the render had then delaminated, obviously taking the paint with it. I don't know what the difference in the good and bad area was on this building, i suspect the tower had new render.