Mould is a super contentious issue between tenants and landlords. I’m active in several tenant-based and several landlord-based forums on Facebook, and the standard response is always “the other guy did it”.
It’s not a straightforward issue. Well it is, but it is very case dependent. The cause in one home is almost certainly not the cause in another home. That’s why it take some real skill to diagnose the issue. Following are some things to look for broken down into structural (landlord’s issue) and operational (tenant’s issue).
Maintenance:
- Mould on ceiling – may be accompanied by water stains. Check roof tiles are all in place, they can get dislodged in storms or with people walking on them. Tiles can also crack, and it’s possible that the roof was constructed at too shallow an angle in the first place. Check for rusting sheet metal roofing. Overlapping sheet metal can promote wicking between sheets and rapidly rust out newer sheets.
- Mould high on walls – Check that the gutters aren’t blocked or overflowing. In some cases it’s possible for them to back up and flood over into the roof space, and even more likely if you have hidden or box gutters. Box gutters can rust out and leak directly into the roof space.
- Mould low on walls – could be rising damp. This is where water wicks up through piers or slabs and eventually gets into wall framing and brickwork.
- Mould on carpet – poor subfloor drainage or ventilation. This is a really complicated issue. It’s not as simple as dry is right. In clay based soils in our area we want consistency, this avoids the swelling as the ground gets wet and the shrinking as the ground dries out. This swelling and drying leads to movement in the foundations and cracking in the house. Consult an expert!
Operation:
- Mould in bathroom – mould on ceiling potentially indicates extraction fans aren’t being used. This could also be because the fan has failed, which would be for the landlord to repair or replace. Regular long hot showers would really exacerbate mould in bathrooms. Consider shortening showers and running extraction fan for a few minutes after leaving the bathroom.
- Mould in bedrooms – could be a sign of poor ventilation. It’s common in winter that moisture from breath condenses on windows, but this also happens on the walls, floor and ceiling. It may also landing bedding, leading to mould developing there too. Opening windows during the day can help, but using dehumidifiers or desiccants are really the only options to help here.
- Mould behind furniture – could indicate that the room is used by lots of people and pets without getting enough external ventilation by opening windows.
Mould can be a health issue, so act quickly and if in doubt refer to experts.
There are several ways to treat mould but definitely avoid bleach, all it does is take the colour out of it, but doesn’t kill the underlying issue. Instead:
- Wet and Forget Indoor – works well, just search for it on the internet. The last time I got it I think it was a pool shop or even a paint supplier.
- Natural! Tea Tree oil (melaleuca alternifolia) – 1-2 teaspoons per cup of water. Spray on with a demister, wait 60 mins. Then scrub off. Mouldinhomes.com has a recipe here https://www.mouldinhomes.com/removing-mould-with-tea-tree-oil/
SPAI Property Management 