Masonary paint over lime render - what to do?

[anjomi]

My house mainly has lime render on it, and is lime-washed. But on one section, the previous owner has painted it using standard masonry paint (I found a can of Sandtex in the shed, so its probably that). Near ground-level, this is all peeling off, probably due to damp getting underneath it.

So my plan is to scrape it all off and lime-wash it. However, it looks like the further I go up the wall, the harder it will be to get the paint off. I don't want to end up removing too much of the render as I might do more harm than good.

Does anybody have any tips on removing paint from lime render?

Thanks
Anjomi

 

[Ian Bond]

I used steam to get emulsion off lime plaster, but it was a long and tedious job. The plaster was rendered directly onto masonry in this case, and not applied to laths.

I did it this way to save money on chemicals, but had to be very careful as it would be easy to damage the plaster.

The steam method might also be tricky to do up a ladder :wink:

You could ask Strippers of Sudbury for advice on this - they may be able to recommend a suitable product and give you an idea of cost per square meter.

http://www.stripperspaintremovers.com/contact.htm

 

[Gervase]

A repointing job I was on last week had been Sandtexed, and Strippers was able to provide a bucket of gloop which worked a treat at getting the old paint off.

 

[glayzell]

i had emulsion on top of some plasticly bitumen type paint on top of lime on lathes.

heat gun, many hours an loads of blades, as soon as they get blunt they start eating into the lime. Arms like hercules afterwards.

 

[skier-hughes]

And finger tips like musroom gills if they were anything like mine

 

[anjomi]

Thanks for the advise so far.

I got some samples from Strippers, and they took the top layer off no problem. This was the Sandtex layer.

However, underneath that I have two more layers before the render, both of these are white, and quite thick. Neither of them appear to be polymer based, and I think the top one is impervious. They are both quite crumbly when you scrape them off. Does anybody have any idea what they could be? Could it be limewash or whitewash, how could I tell?

I'll try the heat gun next, but I don't think it will touch it.

 

[Ian Bond]

Limewash is like a thin sheet of chalk - quite brittle and crumbles easily, unlike some plasticcy paints.

If you spray a little water on the wall it should soak in nicely to limewash, and the wall should dry quite quickly - with some emulsions and masonry paints the water tends to just run off the wall - no soaking in.

SPAB explain how to identify limewash better than I can:

http://www.spab.org.uk/html/advice/technical-qas/technical-qa-18-limewash/

I agree - hot air gun will be useless stripping paint off an exterior wall.

Just remembered a money saving tip from the Guardian a couple of weeks back. Someone was stripping layers of paint from a cornice, and rather than using expensive poultice strippers, tried porridge.

They reasoned that it was the moisture that softened the paint layers, so mixed up the porridge good, thick and hot then trowelled it on and covered with cling film for an hour or so. They said the paint came off wonderfully easily.

Don't eat the porridge afterwards though, and don't blame me if it doesn't work - write to The Guardian addressing the complaint to the Space section of the Weekend Magazine.

I wouldn't try porridge outside either - the local wildlife will be at it in no time.