Damp walls
Patchy wall condensation is often confused with penetrating damp. Removal of a small area of plaster should tell you which it is. If it is condensation, the brick area behind will be perfectly dry; if it is damp, try to find the cause. At ground floor level it could be a faulty damp proof course; upstairs it may be a faulty gutter or down pipe or driving rain on porous solid brickwork might be the reason. Try to increase the circulation by warm, dry air in the affected area, but remedy the cause of the problem as soon as possible otherwise the trouble will recur.
Ceilings
Those with a high gloss finish are most susceptible to condensation.
To test for damp floor, place piece of glass on ring of Plasticine over affected area. Moisture on underside of glass indicates penetrating damp. Moisture forming on top of glass indicates condensation present
Damp floors
These are often caused by damp from the outside and not by condensation. You can make a simple test to see which condition is present with a piece of glass on a ring of Plasticine. Condensation on floors usually occurs with cold surfaced materials on concrete, such as tiles in the kitchen. The most effective remedy is to substitute existing flooring with warm-surfaced flooring.