Many landlords find themselves getting a phone call from a tenant to find out that all of a sudden they have a serious mould growth problem in one particular room or in a number of rooms in the house. The house may have had no problems or only a small mould growth problem for many years leaving the landlord mystified to why all of a sudden he or she has a serious mould growth in the property.

If a solution is not found fast not only has the landlord the problem of the tenant leaving, more serious damage to the internal fabric of the building can be caused as the mould will grow far more extensively on the inside of plasterboard. Also interstitial condensation can occur inside the wall and ceilings wetting the insulation which will reduce the valve of the insulation for keeping heat in but more seriously could lead to fungus, rot and mould growing inside the building.

The problem is that mould spores are naturally in the air all the time and can suddenly start to growth when the relative humidity of the air in winter is over 70% for as little 24 hours.

The relative humidity in a tenants property can stay above 70% very easily as the tenant tries to save energy in the house by closing windows, trickle vents and switching off noisy extract fan which come on for long periods every time the bathroom light is switched on. The fans in the kitchen and utility room are often not fit to extract the large volume of water vapour that some tenants produce through cooking practices and drying of clothes.

The following video will show the problems and solutions to condensation


Controlling Condensation and Mould Growth – an NLA Guide


The Solutions

1. Adequate ventilation:

We can use an anemometer to check the ventilation rate of you existing fans to see if they are fit for purpose. If the fans are not suitable we can offer a large range of extract fans to solve different problems such as silent inline fans, silent axial fans, humidity fans and filterless fans which are constantly running at a slow speed and increasing very quietly as the humidity level rises without the tenant been able to switch the fan off. This fan is easily maintained and very energy efficient. For our full range of extract fans see our product page.

2. Adequate heating and insulation:

With the aid of technology from thermal imaging we can see clearly areas of your building that are missing insulation or been affected by thermal bridging which will lower the temperature of the wall or ceiling and be more prone to mould growth. With the use of a moisture meter and a thermal imaging camera areas at risk of condensation can be clearly shown. With the use of thermal imaging we can also see problems with the heating system such as sludge build up, air locks and improperly balanced radiators which can cause rooms not to heat to a required level. See thermal imaging for the benefits, we also have a borescope which can see inside the wall through a 11mm hole to confirm missing insulation.

3. Reduction of humidity:

We have a range of whole house positive input ventilation units from envirovent which will lower the humidity and ventilate the whole house very energy efficiently. These units are usually place in the loft and cannot be tampered with by the tenant. These units will deliver constant filtered fresh air 24 hours a day lowering the humidity and stopping mould growth. See our video on about positive ventilation.

4. The use of mould spray and paint additive:

We have mould spray which is very good at removing mould stains and paint additives to stop mould reappearing again. Call us today about more information on these products,