Damp smell from under floorboards

[withnail1969]

We moved into a link detached house that had been empty for 2 yrs but had been renovated.
It smelt a bit damp and we thought it due to being empty for so long.
9 months on there's a definite stale smell coming from under the floorboards. We've had 2 rotten joists replaced and replaced all 13 airbricks and this hasn't improved the smell. There seems to be a lot of old rubble underfloor but it's not blocking the airbricks.
Would removing the rubble help? What else could help us remove this horrible smell.
There was rising damp prior to us moving in but the work has been done and checked, the plaster is fine. I don't think it's dry rot as I've smelt that previously and this is more musty/old/stale. I'm currently using a dehumidifier, it's collecting lots of moisure but not really improving the smell.
Any advice gratefully received.

 

[mattysupra]

if you have rubble under floor it can cause problems, remove it! Your air bricks should be on opposite walls. If not they will give problems. Also make sure they are the correct size to the air flow needed for the size of property. You could also have a dpm bridge. Make sure there is nothing above the dpm on the outside (decking, soil, etc) every thing should be 6" below dpm, unless grave drain away etc.

 

[JohnD]

might there be a leaking pipe or drain? Old water pipes often perforate - especially at elbows e.g. where they turn upwards.

Sometimes people drain radiator systems by slacking a joint and letting it run away under the floor

do you have oversite concrete or is it bare earth under the floors?

 

[withnail1969]

Should i be able to lift floorboards, clear the rubble and relay them pretty easily or is there a knack/knowledge needed?
There's no concrete under the rubble, just earth.
If I put washing up liquid on the central heating pipes under the floor and turned it on would that show a leak?
Thanks for the advice!

 

[JohnD]

square-edged floorboards (found in older houses) are easy. T&G in modern houses is more tiresome. T&G chipboard is very tiresome, and you can expect to put down new after you've broken it out.

If there's just earth under the floorboards, it will always tend to be damp. If the problem is coming from there you can lay polythene and put concrete over it (the concrete is mostly just to stop it floating up).