What to do with old sandstone walls

[ScottishGasMan]

Checking an old chimney at my house today, with a smoke bomb, found it not only blocked but the smoke was pouring out between the external brickwork where pointing has faded and failed.

Looking at the wall its in need of some attention, as where smokes getting out, waters getting in.

But I've no idea what my options are with sandstone? The house is approx 100years ol, pics below show side wall and one of internal wall, front of the house was re rendered just before I bought it by a couple of really old sandstone specialist guys that I presume knew what they were doing.

I certainly won't be diy'ing this one, but would like an idea of the dos and donts with sandstone first while looking at my options. Ie rough casting/re rendering/painting etc

Untitled

• ScottishGasMan
• 8 Mar 2015
• 1

Untitled

• ScottishGasMan
• 8 Mar 2015
• 1

Untitled

• ScottishGasMan
• 8 Mar 2015
• 1

 

[ree]

You have whats called Vermiculated Rustication ie. the way the stone surface is worked.
You also have S&C strap pointing - which should be removed (it literally catches water) and raked out to a depth of 20mm to 25mm and re-pointed in 3:1 sand and lime.

Moisture will be entering the elevation thro the pointing not the actual stonework unless the acid soot in the flues has eaten the stonework away.

Various claims are made for various liquid "water proofer" applications - research them. FWIW: SBR have a good reputation.

Rendering would have to be a site call but, personally, i'm dead against render unless nothing else will work. Thing is, any render will bring with it its own down the line possible difficulties.

The interior surface behind the framing appears to be dry? Are you having damp issues? What kind of interior wall surfaces do you want - exposed stone or plaster?

 

[ree]

OP, I've split this long reply.

1. you have a cellar, is it well ventilated? Only one air brick visible.
2. the flue soot can be seen grinning thro the affected stonework following the flues to the c/stack.
3. The S&VP seems to have had its day.
4. the flat capping on the stack should be flaunched to allow water to run off.
5. There is an unwrapped or lagged metal pipe coming from the ground near to the meter.
6. Do you have any interior damp issues?
7. Are your floors level and firm?