Hello All

Long time no see. I wonder if anyone can help?

I'm two months into the conversion of a listed coach house into a private dining/function room for a hotel.

My problem is that the 600 mm thick limestone rubble North walls have an inaccessible two metres of earth up against them. I was proposing to tank them with Newton type crating draining away but then had hoped to insulate and lime render the inner face. The original 2007 stone wall thread is long gone and I wondered what current thinking is on insulation, breathability and lining.

The double height south facing (wainscotted to 1200mm high) well glazed room will sit 20 plus diners, be thoroughly insulated top and bottom, have a wood stove, and underfloor heating so fairly regular heat but my client wants to hang pictures along the north and gable walls: an independent ventilated timber frame was my assumption but much the old thread criticised this approach. Certainly the conservation officer would like a light touch with the imperfections of the old wall on show.

Any help gratefully received.

Ralph

We lined the inside of our stone barns with Newton Newlath 2000 (now called System 800/805 I think). It is breathable heavy-plastic waterproofing but the dimples hold it off the stonework to allow a little airflow and clear drainage path. I don't know if it was really necessary but I like that the studwork is fairly protected and it keeps a lot of wind out of the insulation so I think I would use this method again.

But inside this we had timber studwork and a fair bit of insulation and finally a solitex breathable membrane (can't remember which) below regular plaster boards.

Is there a chance much water could come through the stone though from all that piled up earth? I would still be inclined to worry about where it would go if you cannot make sure it can drain at the bottom.

We have one high-walled old stone barn that we use as a garage. Largely untouched except for a new roof, re-pointing with lime mortar, lime render inside, and an old concrete floor, and this has about 2 to 3 ft of earth above this floor outside on the south face. When it rains heavily enough water comes through to form puddles inside :-/ I'm glad it's not 6ft of earth.

Our conservation office and planners were fine with lining the inside. They were not OK with changing the outside appearance with insulation.

Thanks everyone. We definitely can't French drain so drained tanking is going in; then the walls are to be studded in insulated metal stud work which I understand has less risk of shrinkage if its near a damp /condensing wall.

You're suggesting an additional breathable membrane on top of that under whatever finishing board and plaster?