Finishing Daub Panels

[mnorris3]

Sorry for the barrage of questions, but I'm a bit stuck...
What is the best finish for daub panels that are not covered in lime? I am experimenting with lime wash, but the results are not great as the staw in the daub is over visible.

Many of the original infill panels in the house have a ~2mm coating/covering over the daub - would this be lime plaster or distemper? These look much better and I'd like to recreate this - any thoughts?

If you think its lime Can you 'skim' lime plaster on to daub, if it does not have the 'finger' holes in the surface to key the plaster?

If distemper - how should I prepare the surface? And do I limewash over this?

Finally - would the answers to the above be any different for a bathroom, given steam etc?

Thanks

 

[Ian Bond]

Have you seen the Daub article on the Information page of PPUK?

It's written by Ian Pritchett, and there's a more detailed version here:

http://www.buildingconservation.com/articles/wattleanddaub/wattleanddaub.htm

Lime plaster then limewash (not distemper) would seem to be the best approach.

 

[biffvernon]

You can certainly put lime plaster over daub. You could also have put a mud layer without straw over the daub. And of course you can put lots of layers of limewash on. It gradually builds up to a thickness that covers anything. Half a dozen coats usually obliterates most things.

 

[mnorris3]

Thanks guys. I'll carry on limewashing a test area with more coats and see what it looks like. If that doesn't fix it - then I'll have a go at the mud of lime.

Should I add an additive (linseed or something?) to limewash if being used in a bathroom?

MAt

 

[Ian Bond]

Do not add linseed oil, unless absolutely necessary. Perhaps for exposed external renders.

If you use limewash you must accept a 'non perfect' finish, quite unlike that you would get with modern emulsions. Moisture will darken the limewash. It will take many coats to cover old plaster, especially if it has been much patched and varies in colour.

The non-uniform, matt appearance of limewash is lovely, and it suits older vernacular buildings perfectly. That's not to mention the importance of breathability.

You probably do not want a perfectly flat surface, given the nature of your house, it would look wrong. Nicely undulating surfaces perhaps. If the daub is very rough, compared to the original panels, lime plaster it first. Then limewash. Limewash alone will not cover the roughness in a few coats.

Done right (suitable substrate, thin coats, at least 2 days between to allow curing) limewash will not easily rub off on you clothes etc. Without anything added.

Suitable substrates would be porous: daub, lime plaster, brick, stone, timber. Not gypsum plaster, or over modern emulsions. It can be made to stick to this, but is more likely to rub off. I would always remove as much as possible of any modern paints, and get back to the lime plaster surface before limewashing. A heck of a lot of effort, but worth it.

 

[Ian Bond]

Oh and you can use limewash in the bathroom, but take the usual measures to ventilate and control moisture levels. Open a window and shut the door after baths.

But as I mentioned above, the limewash won't behave like a modern emulsion: condensation running down the walls and then the paint peeling off.

It'll go darker in places, and the colour will vary as the moisture level changes.

And people used to 'perfect' uniform modern finishes will ask you when you are going to decorate

That's one of the problems with old houses. If we've repaired it, and conserved it properly, it looks like nothings been done.