Is my limewash mix feeding mould?

[Roger H]

I've a ground floor kitchen that is sunken into the ground at one end. The walls are a double skin of sandstone with a rubble fill. They are pointed with lime inside and out after I'd ripped out the old cement. Prior to this, they had been poorly dry-lined with plastic sheeting and hard board. On removal of this, and of the internal cement, water literally gushed from the wall.

I fitted a land-drain outside and lime washed inside with a mix of 50% hydrated lime putty 50% water with a glug of linseed oil.

The walls are now dry to the touch but I suspect are cold bridges as there are occasional black mould points on them. In general, I think I've done all I can to dry out the wall but am wondering what can be done to tackle the mould. I fear that more limewash with oil will just be feeding it? Would an oil-free limewash work or is there something I can add to the lime (salt?) to make it a less comfortable environment for them.

Any advice appreciated, Roger

 

[MatthewC]

I would have thought that it was most unlikely that limewash could be feeding mould - it's only calcium hydroxide and pigment plus the linseed oil you added. Is your drain keeping the water away completely from the wall? Is the kitchen area well ventilated?

Matthew
http://houseintheenchantedforest.blogspot.com/

 

[MdB]

I would guess if anything it would be the linseed that was being fed upon by the mould. However, mould seems to grow on anything damp including my glazed bathroom tiles so it could well be that there is just enough stuff in the air to keep it alive.

 

[Penners]

I agree with both of the above. Your situation sounds like a cert for condensation, which is almost certainly the cause of the mould.

As Matthew mentioned above, I would try to take steps to ventilate the wall on both sides as much as you possibly can.

 

[Roger H]

Ok - thanks for your thoughts. My feeling is that it is mainly condensation. I've aired the outside of teh wall by putting ribbed palstic between the wall and the ground (as it is a semi-sunken room) with gravel and french drain beyond.

Trouble is my buyers are insisting on injecting the wall with a dpc, but you'll all have heard that sort of tale before

 

[robgil]

What kind of linseed oil did you use? I used cheap stuff on a door and it's covered in mould and it's very hard to remove without it coming back.