Frequently Asked Questions
Q1. I have blistering paintwork on the inside of my walls. What causes this?
A1. This could be due to either bad preparation of the surface prior to painting or possibly the signs of Damp.
Q2. In addition to the blistering of the paintwork there is a white, fluffy substance on the walls. What is this?
A2. This is efflorescent salts, most probably sulphates. They are brought to the surface during the process of evaporation. Have your walls checked for the presence of Damp.
Q3. I have damp patches in my carpet in the middle of our ground floor lounge. What could cause this?
A3. Depending on the age of the house, this could be due to either the failure or absence of a damp proof course (dpc) beneath the floor slab or the beginning of the break-up of an old malthoid dpc used prior to the introduction of modern plastic dpc sheeting. This requires professional treatment and you should contact a damp specialist.
Q4. I have damp patches appearing on the inner face of my external walls at a height of about 2m from the floor. What causes this?
A4. Once again this could be due to a number of reasons. First check the height of ground outside your walls. If this is above the height of your floor it could possibly be Rising Damp; if you have flower boxes on the outside it could be Lateral Damp due to a failure of waterproofing; if close to a window it could be due to leaking joints between the window frame or sill; it could also be due to descending damp from a leaking roof or possibly even Penetrating Damp through porous bricks or faulty mortar.
Q5. I have a basement/cellar and there is water appearing on the floor after heavy rains. What should I do?
A5. The waterproofing on the external face of your walls has obviously failed. Since we cannot now get access to this side of the wall we will have to treat the inner face of the walls with a cementitious slurry or other suitable waterproofing material to stop water ingress. In extreme cases it may be necessary to line the walls and floor with a drainage membrane and channel the water to a sump from which the water can be evacuated by means of a self-actuating pump.
Q6. I have efflorescent salts and damp appearing on my walls and ceiling beneath an upstairs balcony. What causes this?
A6. Either the balcony has not been waterproofed prior to tiling etc or the waterproofing has failed or did not properly cover the joints with outlets and side walls. A further problem could be a failure to adequately waterproof parapet walls. Have the balcony checked by an approved applicator.
Q7. I had my walls treated for damp a year ago but blistering and efflorescent salts have now appeared in the wall above the area that was treated.
A7. Damp can rise in walls to a maximum height of 1.2m above ground level. Where treatment fails to stop water ingress and the walls have simply been treated with a slurry but not to the full height of 1.2m, damp will continue to rise in the walls and damage any areas in between.
Q8. What causes the damage in my walls?
A8. All building materials contain a certain amount of moisture and natural salts. Only when excessive quantities of both are present do problems normally occur. Usually this comes from a failure or absence of dampproofing material which allows moisture and salts from the ground to enter the brickwork of our properties. As evaporation takes place, the salts carried in the water are drawn to the surface where they accumulate and start attacking our plaster and brickwork. Some of these salts are hygrophobic i.e they attract moisture from the air. If we fail to remove them completely they will continue to attract more salts to the surface as the moisture evaporates and the problems will persist.