You have to find what’s causing the moisture problem and fix it, or the mould will come back. Remove any mould and material that the mould has grown on. It’s important to protect yourself and others while you’re doing this work.
You may need the help of a building expert (such as a construction engineer or a building repair or construction specialist) for foundation, roof, or exterior wall problems. You may need a plumber for leaky plumbing fixtures or sewer backups.
Porous and semi-porous material
Porous material has openings on the surface or has cavities inside. Examples include carpet, upholstered (covered in fabric) furniture, wallboard, ceiling tiles, clothing, books, and pressed wood products. You can’t clean these materials, so you need to remove them. (Restoration specialists can restore some porous materials.)
If there’s mould growing in a heating, ventilation, or air conditioning (HVAC) system, replace porous materials such as filters and insulation lining ducts. You’ll likely need to call a company that deals with HVAC systems.
With semi-porous material like wood framing, you can often clean the surface and leave the material in place. If the mould has gotten into the material, you need to remove the material.
You can usually clean non-porous material such as metal, plastic, and glass.
Clean non-porous materials using a HEPA (high efficiency particular air) vacuum, wiping with a damp cloth, or pressure washing.
Using biocides (chemical products like chlorine bleach that kill living organisms) isn’t usually recommended for removing mould.
Biocides may be needed for sewer back-ups or surface floodwaters on certain HVAC parts. Check with the manufacturer of the parts for what they say you should use. Not many biocides can be used in duct systems. They must not leave any residue in the HVAC system and must be certified by Health Canada. Contact a company that works with HVAC systems for help.
The most important thing is to protect yourself and others when you’re cleaning and removing mould. Follow this advice:
Depending on the type of building, the size of the area, or how long it takes, you may need professional help to clean and remove mould.
1. Less than 1 square foot of mould that is close together (contiguous):
2. Between 1 and 10 square feet of mould that is close together (contiguous):
3. Between 11 and 99 square feet of mould that is close together (contiguous):
If you own and live in the home, it’s best to hire a professional contractor who knows how to clean and remove mould and an environmental consultant. If you decide to do it yourself or have regular cleaning staff do it, follow this advice:
For rental home, public facilities (such as schools, daycares, hospitals), and commercial buildings, follow this advice:
4. For 100 square feet or more of mould that is close together and marijuana grow operations (MGOs):
Go to Alberta Health Services Environmental Public Health to learn more.
Current as of: February 18, 2021
Author: Environmental Public Health, Alberta Health Services
This material is not a substitute for the advice of a qualified health professional. This material is intended for general information only and is provided on an "as is", "where is" basis. Although reasonable efforts were made to confirm the accuracy of the information, Alberta Health Services does not make any representation or warranty, express, implied or statutory, as to the accuracy, reliability, completeness, applicability or fitness for a particular purpose of such information. Alberta Health Services expressly disclaims all liability for the use of these materials, and for any claims, actions, demands or suits arising from such use.