Mould: How To Clean & Treat

Mould: How To Clean & Treat

Here’s how to get rid of mould.

All mould loves cellulosic material – so all wallpaper, grout, plaster and plasterboard and wood, carpet – in short all household fixtures and fittings are subject to mould contamination and it isn’t easy to get rid of.

Where does damp come from?

  1. In a big old house the damp course could easily be compromised, assuming that there is one in the first place.
  2. From broken gutters, window frames, holes in worn brickwork and grout, leaking roofs and tree roots. Damp wicks through the brickwork and wall finishings. As it dries off, the mould grows on the cellulosic material.
  3. From high humidity in unventilated bathrooms and showers, but also in 50/50 humid atmospheres

Mould is a symptom of damp and high humidity and to remove the mould you have to remove the source of damp:

  • Humidity is controlled by a dehumidifier. Showers and bathrooms should be well ventilated and dried with a dehumidifier where ventilation is inadequate
  • Wipe the shower walls down after use to control obvious damp.
  • Treat the damp by cutting it out of the wall finishings (plaster and plaster board) since in extensive mould this will be behind walls, so treating what you can see is a waste of time – it grows back rapidly.
  • Seal all window frames internally and externally
  • Fix broken and blocked gutters. You will see a greyish line from the gutter down the walls –this is rainwater dripping onto (and getting in) the walls
  • Some old stone-built houses may not be able to be damp-proofed by cavity wall insulation and bear in mind that this may add to the damp problems. If this is the case then keeping as much water out of the house as possible is all – important.


Mould Treatment

Once you have sealed up your leaks and holes and run the dehumidifier the house will need the walls and voids treating to get rid of the mould. There are two ways to do this:

  • Wash down the mouldy areas thoroughly with borax as a detergent. Here’s the rub. Borax is banned in the EU (although you can still get it online) Rinse off and recoat the area by spraying with borax as a surface coating leaving it to dry.
  • If you can’t get borax, clean the mouldy areas thoroughly with detergent solution to remove the black surface mould, rinse thoroughly and leave to dry. You now have a choice: wash with neat white vinegar and tea tree oil or clove oil or coat the mould with a commercially available fungicide (some sanitisers are fungicides so look for one) This does not mean bleach, which doesn’t work on mould and just damages surfaces making the situation worse. By doing this you will have killed off the sopres as well as the fungus. However you may need to retreat when the fungus reappears. Mould spores are everywhere and will always reappear when conditions are right for growth.
  • Recommended fungicides: if you can’t get borax (do not look at borax substitute) then commercially available products like Byotrol work well. The BS EN you need to look for on any product is BS EN 1650, 13697 and 14348.

Finally walls can be painted with anti-mould paint – which is paint containing an antifungal product. Be under no illusions about mould contamination – it can be the cause of chronic ill-health and anyone allowing it to flourish can open themselves to a claim against them if they have not done all they can to eradicate it.