Earth / Mud mortar walls, what to do?

[agbagb]

I'm getting to the "end of the begining" stage, most of what's earmarked for being peeled back or assisted in falling off, has been done. We now have 5 interior walls that are bare sandstone with clay / earth / mud mortar.

Some walls are going to be left as bare stone and some limewashed (some parts show evidence of limewashing, with later lime plastering).

What would be best practice to deal with the earth mortar?

It looks, in parts, like some of it has been smoothed over, filled but not really pointed with lime plaster (haired)
In parts the mud is flush with the stone surface and I'm loathed to start digging it out so I was thinking of compacting it in, taking a bit off if required to give maybe 1/2 an inch to point / plaster the joints. Or what about leaving some as mud mortar?

The photos should give an idea of the situation:

a close up showing a bit of lime that survived the cement render stripping:

The kitchen wall :

All sugestions welcome.

 

[MdB]

We raked our mud out and then repointed in lime. Seems to have worked.

 

[angrybird]

We raked our mud out and then repointed in lime. Seems to have worked.

I remember seeing Mdb's pic of his stone walls and loved them so much!! I did the same to mine, raking out the mud and ash and repointing in lime.

 

[MdB]

Having exposed stone is a modern fad and isn't considered traditional. It does look fab though in my opinion (and my guests) but only about 50% of people here. The rest think lime plastering the wall would be better as this is more likely to have been what the wall was finished in originally. If the house is unlisted then this really comes down to taste and is up to you to choose. In my view, it can always be lime plastered later if needs be.

Be warned though, building control may well see it as a change in wall finish which then requires the wall to be insulated properly. This will mean 80mm of celotex or similar.

 

[88v8]

Our mud mortar was raked out and pointed (in cement grrr). Now partially redone in lime.
Try not to rake out the pinning stones.

I'm not a fan of bare stone walls (says he living in a house where many are...), although it's nice to see some of the bones of the house. We have a mix of studwork infilled with wattle or brick, stone, and stone plastered in lime. Wouldn't want all stone. Just my view.

Ivor

 

[MdB]

Wouldn't want all stone. Just my view.

I would probably agree with that. We only have the end walls in stone which is about 20% of the house.

I do know, that if all our house was made from stone, I wouldn't want to be the poor bugger who has to repoint it all...

 

[agbagb]

Thanks all, I think that's about settled it. Rake out a bit and lime point it is.
It won't be all the walls and some may be limewashed. And like you say MdB, It can always be plastered over in the future, so no harm done.

I'm already a poor bad word, O.H. says it'll not take me two minutes.

 

[88v8]

It'll take you a lot less time than knocking out the cement :x

When you rake out, beware of raking too deep in search of 'sound mortar' because there may not be any. Also, try to leave the pinning stones in place. Perhaps they don't matter any more, perhaps they do....

And, at the risk of statin the bleedin obvious, the earth mortar has tremendous suction, so you'll need to wet and rewet very well to make your lime mortar go off.

Ivor