Solid Concrete Floor

[Bart1664]

Well, we have recently purchased a cottage that was built in 1969 on the foot print of a much older cottage (probably dating back 200 years). However, we don't have any detail of the quality of that build and I have three questions I hope someone can offer advice on. The external foundations show a brick base followed by a visible dpc and air bricks around the property. It is faced in traditional stone as apposed to brick and does appear to be constructed with a cavity wall.

 

We are now unexpectedly experiencing some patches of damp on the internal walls mainly in the lounge just along the top of the skirting boards. We have done a great deal of research on damp and we are not swayed by the usual arguments of 'rising damp' and the usual remedies suggested by many of the 'experts'!

 

We have stable moisture readings in the lounge of 49% and 52% and regularly vent the rooms.

 

We have had the room examined by a builder who is also a 'qualified' damp assessor and he suggests that the plaster used in a recent attempt at renovation by the previous occupants was the 'wrong sort' and was probably in contact with the solid concrete floor. He used a gadget that had about 5 settings on it to probe the floor and walls and said that he was getting high moisture readings at the damp patches and that below one point on the concrete floor showed that the be 'saturated'. 

 

His suggested remedy is the take off all the internal plaster and re apply using the correct one (maybe with lime in it) and ensure that there was a sufficient air gap between the floor and plaster.

 

This then brings me on to my second issue - The concrete floor

 

The builder has suggested that 'potentially' this may not have a membrane within it and he suggests once the plaster is off the walls he will grind back the surface and lay a membrane across the whole floor and under the internal walls.

 

Does all this sound correct/reasonable?

 

My final question is that I have had conflicting advice regarding the external pointing of the stone work. Lime mortar or concrete? I'm told that because the cottage has a cavity it does not need to be lime mortar and can be normal concrete.

 

Many thanks in advance.