Before starting on a round of decorating, we want to figure out if we have to do any work first on some symptoms of dampness but we aren't sure what the problem is (probably there is more than one).
First, for background, the house is a detached bungalow built in the 1930s. It is pebble-dashed, not painted. There is a damp course but no cavity wall insulation. The surveyors report from when we bought the house back in 1998 noted some dampness on an internal wall that was put down to a leaking pipe which had been repaired satisfactorily, but no other problems. Roof and guttering were replaced a couple of years ago and we think they are working OK - the attic seems dry, there are no leaks and no water running down outside walls from overflowing guttering.
Now here are the symptoms.
In our main bedroom, if we leave clothes in plastic storage boxes under the bed for more than a couple of months they sometimes come out smelling a bit damp. Two corners of the room that are on the external walls build up a small black mark on the wallpaper over a period of months if they aren't wiped off (at the bottom, just above the skirting board). We were away for a couple of weeks recently (with the heating being off and no-one living in the house) and when we got back there was a faint smell of dampness in the room.
The wall paper tends to peel off the walls underneath windows in two other rooms although it isn't noticably damp to the touch. We had some problems with this many years ago, which we thought had gone away when we had double-glazing installed, but it seems to be happening again. In one of these rooms we also notice that clothes stored for a long time in drawers underneath the bed also tend to smell a bit damp.
There is a crack in the pebble-dashing near one of those windows may explain the problem in one case. Clearly, I should address the visible crack in the pebble dashing - how do I know how much of it needs replaced or can I just fill in the small crack?
Is it worth investing in a dampness meter to measure how serious the problem may be? I see that some devices are marketed as being for wood and others seem more general - is there anything I should be looking for?
Is this a job for specialists to assess and how would we select one that is reliable?
Any advice would be welcome.