Removing mould from walls can be harder than it seems. There are health effects to worry about and there is always the chance that it can come back after all that hard work. It is therefore imperative that a sound knowledge of mould and how to remove it is established first.
What is Mould?
Mould is defined as neither plant nor animal. It is a single or many-celled organism that relies on an external food source and the right conditions to survive. Mould will produce what we call reproductive spores into the air for the purposes of just that, reproduction. These airborne spores can prove to be hazardous to human health causing problems such as allergies and infections and can be toxic given the ‘right’ situations.
Why Does It Grow?
Mould spores are present everywhere, indoor and outdoor. Some environments will have higher concentrations than others, such as living near a park or forest, however, there is always mould spores present in an environment. What causes these spores to grow into the mould is an important question to ask. By eliminating the source, we can effectively eliminate the need for mould removal.
The influences on mould growth are:
Temperature
Mould typically grows beast in 25-30 °C but can grow between 0-30°C
Water Source
Mould needs water to support its growth. Leaks and/or condensation play big parts in mould growth
Food Source
Mould also needs an organic food source in order to grow such as wood, plaster, or dust. While mould cannot get nutrients from inorganic materials such as metal, glass and plastic, it can grow on the thin dust layer sitting on top of these materials.
No Light
While light does not affect directly the growth of mould, the light in a room can heavily affect the amount of moisture in the air and in the environment. The more sunlight the less likely there is to be too much water in the air and on surfaces.
Eliminating any one of these requirements for mould will effectively reduce the chance of mould growing within the environment.
Proper Safety Protection
When removing mould from the wall it is important to wear the right protective gear. When you scrub and agitate mould on surfaces, mould spores are released into the atmosphere. These spores may contain mycotoxins (harmful chemicals attached to spores) and can be hazardous. When removing heavy mould growth, you must wear a protective bodysuit (either disposable or reusable), gloves (disposable or reusable) as well as a P3 graded face mask.
How to Remove Mould from a Wall
Before removing any mould from the room, it is important that the environment is sealed from the rest of the house/building (when wearing proper protection). This will cause any resulting spores in the air to stay within the environment. If there is a window you may open it so as to let the spores escape that way.
If the mould is particularly heavy, it would be advantageous to first vacuum the mould with a brush vac tip and a HEPA graded vacuum cleaner. If you do not use a HEPA graded vacuum, the spores will get sucked up through the vacuum and be vented back out into the atmosphere as there was no filter tight or dense enough to catch them. This greatly reduces the number of spores the mould can reduce.
If possible it is also advantageous to run a HEPA filtration unit during and shortly after the cleaning process. By doing this the air will constantly be filtered, removing any spores that might have been released in the room during the cleaning. If you are using a HEPA filtration unit, make sure the room is properly sealed (close windows as well).
The most advantageous and safe way to physically remove the mould off walls is to use two things:
- A Vinegar solution — 80% vinegar, 20% water
- Microfiber sponge and Microfiber Cloth
A vinegar solution is both cheap and safe to use as it does not contain anything harmful to humans.
First, dip the sponge into the solution, scrub the mould with the sponge and then wipe dry with a microfiber cloth to remove any remnants of the solution. Although the smell is not ideal, it will dissipate after a few days.
Do not use bleach to remove mould. While visually it will appear to work, it will only remove the top layer of mould and colour the rest. The mould will continue to grow and the treatment will be ineffective.