Damp can arise for many reasons and when it does it is often the cause of problems including structural damage and fungal infections. These may include wet rot, dry rot, and the moulds that appear as little black dots called aspergillus. While there are many aspergillus species, the common aspergillus fumigates is particularly damaging to health and can be fatal for asthma sufferers and people with a damaged immune system.
Doctors have recently reported that they are treating an increasing number of patients for illnesses caused by inhaling aspergillus fungal spores. As a landlord it is your responsibility to ensure that you provide your tenants with accommodation that is safe and free from health hazards.
Sources of damp
Rising damp occurs when there is a problem with the damp proof layer in the building, and water rises through the brickwork by capillary action. It can result in serious structural damage and fungal infections such as wet rot and dry rot. Fixing the damage can be extremely expensive and is likely to make your property uninhabitable for the time it is being fixed.
Damp can also be the result of a water leak. Just a small leak that occurs in a place that isn’t obvious may go unnoticed for months or even years and can cause serious damage. For instance it can penetrate under floors and seep into walls causing huge amounts of damage. Wet rot and dry rot can also set in and result in very expensive repair bills.
Gutter leaks and faulty downpipes are another frequent cause of damp. The water that cascades down your external walls can cause extensive damage and can penetrate through to the inside of the building causing damp patches that attract fungal growth and damage the plaster. The same applies to leaking roofs.
Damp can result from inadequate ventilation. If your property has been fitted with replacement double glazed windows, then it is possible that the air-flow that would have occurred naturally no longer does so. Modern double glazed windows and doors are draft free, and unless your installation includes trickle vents for ventilation it is likely that the amount of ventilation throughout your property is inadequate. This means that the air could become saturated with water vapour causing condensation. This is likely to encourage the growth of fungi the spores of which are likely to be damaging to health.
In the cold weather people are reluctant to open windows to ventilate the property, even after taking a bath or a shower. Trickle venting is unlikely to be able to cope with the resulting amount of water vapour in the air, and it is inevitable that this will result in condensation. While you can’t insist that your tenants open the window each time they shower, you might consider installing an externally venting air extraction system in the bathroom.
During the winter it is almost inevitable that your tenants will dry their damp towels and laundry inside your property while keeping the windows closed. Naturally the water that evaporates from their clothes will condense out somewhere else; it has to go somewhere. The result is condensation and damp patches. Tumbler dryers can also be a source of damp if they aren’t properly externally vented. If you are unable to provide adequate extraction, then the alternative is to use a high efficiency condensing dryer.
While you should do all you can to keep your tenants safe, you can’t control their actions. Should your premises become contaminated with dangerous fungal spores which result in health problems, they might hold you responsible. Landlord insurance from More Than includes up to £5 million public liability cover which will protect you from such an eventuality.