Damp through solid floor

moonpenny

Can someone suggest how to rectify this problem?


My son has bought a small 2 bed ex-council house (build in 50,s) which he is in the process of doing up to live in.


There is a small outhouse joined onto the house by one wall. This has been used as a utility room and he wants to do the same.
It has a dropped floor and a flat roof as it used to be a coalhouse. The roof seems intact but there are damp patches at floor level on 2 walls, just where it meets the floor.
The bottom of the walls seem to be hollow and plastered over so it seems there has been issues with it before.
As it used to be a coalhouse it probably is not a cavity wall. How does he correct this?


Also, more importantly, the downstairs floors are all solid quarry tiles and there seems to be some dampness coming through the joins of the tiles in the dining room so there is possibly a problem here as well.


There are Patio Doors at the back and only one row of bricks under this on the outside before the garden backs up and no evidence of a damp proof course.


On the buyers report it said there was evidence of a damp proof injection being done at some point and the holes on the outside are about 18 inch up from the ground. How does that stop damp coming up through the floor?


Anyway, sorry for the long post but if anyone can offer any suggestions to deal with this, I would be most grateful!

sbtools

First things first, the outside coalhouse will probably be single brick, as most were built like that and without any DPC damp proof course as it is classed as an out house. You can hire a damp proofing machine and drill 2 x 10mm holes in each brick at the floor level. Then inject the fluid into the holes, this cures and forms a rubber like waterproof seal. the moisture will always seep through concrete floors if there was no membrane applied under the concrete, which seems likely in this case. you could do a cheap repair and coat the tiles in a polyurathene waterproof sealer, Apply 2 coats. The patio door wall may need re-drilling and injecting again, but make sure there are no cracks in the bricks or the fluid will just leak out into the cavity. If there are any cracked or damaged bricks, they will need replacing.

Hope this helps

TheCyclingProgrammer

Not sure I'd spend much money on this personally. I'd save up, knock it down and have a proper extension built if it were me.

Furts

The clue lies in he comment "a drop down floor". The coal house will be built with a slab at ground level and probably has no effective membrane. It was never intended for habitable accommodation, hence no membrane was needed. It is also likely that the walls are built of this slab, without any foundations. Being a coal house it did not require cavity walls. In essence this is a brick version of a garden shed. The answer is to demolish and build properly

Furts

Quarry tiles are robust and water proof, so the floor issue may not be worrying. If it is just slight damp on a few joints at 1mm wide does this really matter? You could re -grout these. I would not worry provided these are not laid on a timber floor structure that is defective.