Moulds are in fact microscopic fungi and can be found everywhere in the environment and are a common part of household dust. When found at normal low levels these moulds do not cause any concern, however if they are allowed to grow in large numbers they can cause allergic reactions and breathing problems in humans.

What is Mould

The most common place we see mould is on fruit, anyone who has left a peach for too long in the fruit bowl will know how quickly mould can grow. We sometimes also see mould on food that is out of date, even if it is kept refrigerated. Mould is microscopic fungi that grows on plant material and fibres. Mould travels through the air as tiny spores, when these spores land on damp plant material or fibres they can then grow and breed. When enough mould has grown it forms a colony, this is when the normally invisible mould becomes visible to the naked eye. Most mould needs moisture to grow so if mould can be seen growing then this is a sure sign that there is excessive damp.

There are many different types of mould, some are actually extremely useful, the most well known being penicillium which is used to make the powerfull antibiotic penicillin and also for making cheese such as Brie and Camembert. Other moulds can produce mycotoxins which are toxic chemicals produced by the mould. Exposure to mycotoxins is a serious health risk for both humans and animals. Long term exposure to mycotoxins is considered to be of particular concern.

Where Does it Grow

When your home has high humidity the water vapour in the air will condense on the coldest surfaces. This tends to be windows and window frames and walls, especially those that are north facing. Mould can also grow in less visible places, under furniture, behind wardrobes, in corners and sometimes behind drywalls (walls that are covered in a layer of plasterboard).

How to Clean and Remove Mould

Small amounts of mould on surfaces can be easily removed, mix one of ordinary household bleach with eight parts of water. Use an old cloth or scouring pad which can be thrown away afterwards. If there are large amounts of mould then extra precautions would be advised such as a respitory mask, gloves and googles. Wear old clothes than can be put through a hot wash afterwards and open windows while cleaning to allow fresh air into the house. If mould has infected carpets and platerboard then the only option to remove the affected areas and replace with new. Any cleaned areas should be allowed to dry completely.

Mould on sealant around baths and shower trays is very common and is due to the regular wetting of the sealant from baths and showers. Using a mould resitant silicon sealant will slow the growth of mould but eventually most sealant ends up with some mould growth, especially on shower trays. The only effective method to prevent mould growth on sealant is to dry it everytime after a bath or shower, this is often not practical so most of us accept that over time the sealant will go mouldy. While the mould can be killed and removed by using bleach, the black staining is permanant. The most cost effective solution is to remove the sealant and replace with new. This is one area where you should not cut costs, a high quality mould resistant silicon sealant will not cost much more.

How to Prevent Mould

Just follow these easy steps to prevent mould from growing in your home.

  • Ensure that any existing mould is properly cleaned up.
  • If the excessive damp was casued by a fault such as leaking pipes or blocked guttering ensure these are put right.
  • Ensure your home has good ventilation. If bathrooms and shower rooms do not already have one then consider fitting extractor fans.
  • Buy a suitable dehumidifier to remove excess moisture. Run the duhumidifer continually for the first few days to get the moisture levels down, once the excess has been removed from the walls, carpets and funiture you will only need to run the dehumidifier for a few hours each day to keep the damp under control. If you have a more advanced dehumidifier with a humidistat then it can be left permantly on.