PIV Unit


Mould and condensation

Household Mould and Condensation

Mould and condensation


There three most common forms of mould found in the home are:

Altenaria - commonly found in areas of the home that are most exposed to moisture / damp, such as around the bath, the shower curtain, window reveals and underneath leaky sinks.

Aureobasidium - Commonly found on walls or wooden surfaces such as skirting boards, in areas of the home that are poorly ventilated such as behind furniture.

Stachybotrys - Usually present where humidity levels are high and thrives off organic material such as cardboard, wood and paper.


Mould and damp conditions are synonymous with each other and one of the most common causes for mould is condensation. Inadequate ventilation, poor insulation and high levels of humidity in the home being key factors. The average home with an internal temperature of 20 degrees should have a humidity level no higher than 50 - 60%, and whilst this isn't easy to monitor without necessary equiptment to measure it, there are some simple steps you can take to reduce condensation and the spread of mould. If you dry clothes indoors this alone can raise the humidity in a property by 30 - 50%. Prevention is always better than cure when it comes to condensation and mould and there are a few simple steps you can take to reduce both with little cost or disruption. It is important to remember that any house hold mould can lead to health implications so the first step would be to get rid of any mould you can access. There are many effective mould removers available in hardware stores and most leading supermarkets but take care when doing so and always follow the instructions on the product. Keep your home at an even temperature, ensuring that all rooms are heated equally. Keep doors closed when cooking or showering to prevent moist air travelling through the home. If the problem is local to a particular area, invest in a dehumidifier. Any water droplets around the windows / doors dry immediately, similarly to droplets on surfaces left by steam in the bathroom or kitchen areas.

For a permanent and more effective solution we would recommend the installation of a PIV unit (as pictured above) which will improve the ventilation throughout the property. Installing or renewing cavity wall insulation or having all external walls of the property fitted with thermal boards to prevent cold air bridging with warm air.


A larger scale problem that causes mould is of course rising damp. If you find that you have symptoms of rising damp (please see our page for more information) the only solution would be to install a damp proof course (DPC). You can use the contact page for further advice or to arrange a free site visit to examine and accurately diagnose damp issues.