I’ve been wondering how best to redecorate a room whose surfaces are finished in old materials – clay and plaster – but which have been painted with modern emulsion. That may be creating a breathability problem.
Very modern emulsions are impermeable to moisture. Cruder basic emulsions have a certain amount of breathability, but it’s hard to tell which it is, looking at the result at least 30 years after it was last painted. So should the emulsion be removed?
That would be the ideal solution. The walls could then be distempered, which I have read is the usual treatment for inside walls in Suffolk. Distemper can still be bought.
My answer is no to stripping, because emulsion paint is pretty tightly bound to the surface and my attempts to get it off with chemical strippers or wire brushes caused significant damage. The best I could do with a wire brush was to remove loose paint flakes.
So after a year or two of procrastination, I’ve decided to limewash over it, which should not make the breathability too much worse, even if it doesn’t improve it. I ruled out distemper on top of emulsion because I don’t think it will stick very well and it is also quite prone to leave dusty traces on clothes when touched.
But will limewash stick to emulsion? My favourite paint maker, Ingilby of Glemsford, says its limewash with linseed oil can be indeed be used over emulsion, and I’ve tried it in the past on a smaller area and it’s very effective. So I’m using it to completely redecorate two rooms. One of the rooms is the most complete in the house, in the sense that it has walls of unplastered plain clay daub (with straw showing) and a lath and plaster ceiling.
Ingilby’s limewashes can be bought in custom colours so I took along a sample of a creamy off white that we liked, which they copied exactly (and it’s now in their list as a colour with our name on it).
Limewash that I made up myself using instructions from books on lime was very thin and watery, and it was not surprising that the recommendation was five or six coats. Ted Ingilby’s lifelong professional experience of paint technology – not just lime, and including marine paints – has produced a product that fully covers even a contrasting surface in only three coats, the first diluted 2:1 and the second 1:1.
It is still very liquid on the brush and so quite messy to apply, though nothing like as runny as my trial of home made stuff. The floor must be very well covered and exposed oak timbers masked with sticky paper tape, though I’ve found (see photo above) that only the horizontal timbers need masking – Ingilby limewash is controllable enough on the brush to avoid splashing the verticals when painting the panels between them.
This has now transformed decorations which previously were very obviously modern emulsion into a beautiful matt surface with the soft, subtle colouring of limewash. It’s not the purist’s answer – that would be to strip and distemper – but it’s the pragmatic one.