If you have ever had to deal with algae on your walls, you know how unsightly and difficult it can be to remove. You may be wondering if you can simply paint over it and forget about the problem.
The short answer is yes, you can paint over green algae on a wall, but the more involved answer suggests this isn’t the best solution to the problem. Algae will continue to grow under the paint, causing it to peel and giving the algae a foothold to return.
Many people don't realise that the green stains or black streaks on the exterior walls of their homes or buildings are actually algae growth. While algae is a naturally occurring element in the environment, it can cause problems for humans when it starts to grow on the external surfaces of our homes and other structures.
Algae growth is often accelerated by high levels of humidity and moisture, making it common in coastal areas.
However, even homes and buildings in inland areas, or surfaces on the north side of your house, can be susceptible to algae growth if they don't have proper ventilation or if they're located in a shaded area. In addition to causing unsightly streaks, algae can also lead to other problems like mould growth, water staining, and even premature deterioration of building materials.
It can, so this is another potential issue to consider when taking care of your property, both the inside and outside of your property. If you have decking, review the entire deck for damp areas or signs of mould on the surface.
While there are many products on the market that claim to get rid of algae, not all of them are safe or effective. One of the most economical and safe ways to remove algae is with a solution of vinegar and water.
Simply mix one part vinegar with four parts water in a spray bottle and apply it to the affected area. Feel free to mix and match until you find the right solution, if you are cautious, start with two cups of plain water and a small amount of vinegar.
For best results, allow the solution to sit on the algae for at least 15 minutes before scrubbing it away with a brush.
The amount of time it will take for paint to cover and hide algae stains on an exterior surface will depend on a number of factors, including the type of paint used, the type of surface being painted, and the number of coats applied.
Generally speaking, however, it is possible to achieve complete coverage with one or two coats of paint. If the algae marks are particularly stubborn, it may be necessary to apply a primer before painting.
In most cases, however, a single coat of high-quality paint will be sufficient to provide complete coverage and hide algae from your surface.
When it comes to cleaning products, there are a lot of options to choose from. But if you're looking for a product that can effectively destroy algae, moss and mould, there's a clear choice, bleach. Household bleach is a powerful disinfectant that can kill 99.9% of bacteria and viruses.
You might think painting over algae will deny oxygen, which will eventually kill off algae. This isn’t the case, and even when painted over, spores will thrive. You need moisture vapour to evaporate, and if it is unable to, removing algae will only be a temporary solution.
Therefore, the best solution is to ensure you fully remove algae from a wall before you paint it, and this means removing algae, and then treating the surface. Simply scraping algae off the wall is no guarantee it won’t return, you need to remove the source of the growth.
Unsurprisingly, there are paints manufactured to be more effective in dealing with algae-prone surfaces. Algae resistant paint will cover algae for some time, perhaps even up to a year, but it doesn't remove green algae.
Painted surfaces might look good, but over time, mould growth can reoccur because moisture exists, so even specialist paint isn't a long term solution.
Some of these paints are formulated to prevent green algae from growing, or to slow its rate of progress. However, no paint, as of yet, destroys or removes this blight, and over time, algae will grow and show through even specialist paint.
There is no denying pressure washing or a power washer can speed up the process of clearing algae from a painted surface, but there is no distinct need to use specialist equipment.
When it comes to cleaning products, there are a lot of options and many brands to choose from. Use oxygen bleach rather than chlorine bleach, as chlorine bleach damages paint, can warp timber, and the run-off can be harmful to surrounding plants. Using a small amount of bleach shouldn't harm plants, but if you use an excessive amount, plants and grass might suffer.
Oxygen bleach also breaks down the cell walls of algae, and mould, causing them to wilt and die. In addition, bleach helps to prevent the regrowth of mould by inhibiting spore formation.
As a result, this is an incredibly effective cleaner for any home or business where algae, fungi, or mould is present. Sodium percarbonate is also highly effective at removing algae.
Those looking to avoid using bleach on painted surfaces should start with warm water and liquid dishwashing detergent or a commercial cleaning product.
Thankfully, you can remove green algae in a few simple steps:
Simply painting a new coat of paint is a natural step for most homeowners to take when dealing with this issue, but it isn't enough to remove algae or prevent mould growth on walls and wooden surfaces.
Regular cleaning, new paint and looking out for wet areas or moisture build up will help you avoid structural damage of the surface of your walls, decking and roof.
