Our home is a 1930s detached house, brick-built with cavity walls and
suspended timber floors at ground level. There are airbricks to two
sides of the house, with varying degrees of clarity, whilst a modern
extension and a conservatory - both solid-floored - are now appended to
the rear and one side of the original house.
In a recent underfloor excursion I noticed a massive difference in the
dampness of the subfloor between our lounge - which is on one of the
open sides of the house - and study, which is effectively in the centre
of the house with minimal ventilation. In fact the study was cinder-dry
and just covered me in dust, whilst the subfloor in the lounge was
earthy and clammy. On a previous visit both rooms were equally dry.
As well as seeming a bit damp underfloor, the lounge has always been
extremely cold. There are two sizeable radiators, but also an open
fireplace which must remove a lot of warm air. In fact, sometimes the
carpet feels a bit wet on the surface,as if condensation is forming.
Is it generally advisable to insulate the underside of the wooden
floor? There is nothing at present. Will this have a detrimental effect
on the already-poor ventilation, which is presumably the root of the
I also noticed that two airbricks at the rear are actually placed level
with the floorboards, i.e. only the bottom half of the brick is below
floor level. Not surprisingly, my coathanger doesn't get very far in
the top half. Even in the bottom half I would say only 10-20% or so of
the airbrick is clear.
Any advice is welcome, both on the potential damp situation and on
warming the room up as autumn draws in.