Humidity and damp problems

Humidity and damp problems need to be tackled when they are first noticed; as they produce mold, which is not only unsightly but poses serious problems to health. Mold grows where there is moisture.  


Mold and Your Health In 2004 the American  Institute of Medicine (IOM) found there was sufficient evidence to link indoor exposure to mold with upper respiratory tract symptoms, cough, and wheeze in otherwise healthy people; with asthma symptoms in people with asthma; and with hypersensitivity pneumonitis in individuals susceptible to that immune-mediated condition. The IOM also found limited or suggestive evidence linking indoor mold exposure and respiratory illness in otherwise healthy children

Rising and Penetrating damp.  Properties over 15 years old are prone to these problems, normally caused by poor DPC and weatherproofing during construction. “Remedial damp proofing is always difficult”. Of the types of damp we’re looking at today, the first is penetrating damp below ground level, it’s often possible to excavate and expose the walls, and install a waterproof membrane. Personally I prefer to use several coats of bitumas, as against the sheeting technique, which is only as good as its jointing.

Rising damp in brickwork Most buildings are constructed of brickwork directly on supporting concrete beams making it more difficult to tackle. Silicon injection type treatments are becoming available; I believe they work better in “solid brickwork” less so here due to the “claypot “bricks. Electrical osmosis treatment is available; effectiveness is again dependant on the quality of the building work, physical insertion of a DPC is possibly the most effective method but costlier. In many cases sadly there is often no guaranteed solution, the best one can do is to regularly remove the damp plaster back to the brickwork, disinfect, re-plaster and repaint.

Damp rising through the floors is more easily remedied by the installation of a waterproof membrane directly onto the concrete over-site, though the work involved is considerable.

Humidity Carries the same health risks as damp and should be properly treated, not just painted over; this merely traps the living spoors under a layer of paint. Firstly find out why there is mold; in many cases it can be due to poor ventilation and air circulation, easily remedied by installing air bricks, the inner grill should always have an integral fly screen. Mold also occurs at high levels where concrete meets brick for example, or where the exterior rendering is cracked allowing damp. The interior plaster should be cut away, then treat with fungicidal, make good the plastering, then repaint with a mould inhibitor finish. It’s best to cut away the defective exterior rendering, make good the cracks or defects, then re-rendering as necessary then repaint.


It is important to remember that the exterior finish of your property is not merely decoration; it’s the first and most important line of defence in protecting the fabric of your home. It’s unwise to “decorate down to a cost”, better to paint just one façade of your property yearly, but have it done well, not just a quick coat of a regular quality emulsion, which by its very nature is pervious to water. Call Newstar Homes in Spain we will be happy to arrange a visit and discuss any problems you may have regarding damp in your home. In our next epic we will look at exterior decorating.


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