The RTA does not talk about mould directly, but it does say that it is the landlord’s responsibility to make sure that the property is kept in a good state of repair, is fit to live in, and meets all the health and safety standards that apply.

If you have a problem with mould, you should talk to your landlord, superintendent or property manager immediately. You should ask them in writing to fix the problem and keep a copy of this letter for yourself. The landlord will need to fix the problem within a reasonable time.

Both the landlord and tenant have responsibilities when it comes to fixing this problem. The landlord may have to arrange to remove the mould and the tenant may have to do some work, such as helping prepare the unit for the work or taking steps prevent the problem from happening again.

Source: www.sjto.gov.on.ca