damp continued.

[brenda]

the room is heated from time to time by a small electric fire and is not attached to the central heating system.There are 2 small windows which he opens regularly to let air in.
He says that he can feel air circulating around the edges of his bookcase,so are the air bricks working, and letting in water because they are so low down.
The floorboards do not appear to be damp.
would a humidifier help to solve the problem?
all advice very welcome , esp. from builders mate.
The room is used on a daily basis 5/7as a consultation and treatment room .
he is at his wit's end with the prob.
there is a
damp course to the prop. but do not know if this is breached.
Please help if you can.TIA Brenda