What is Lichen?
It is a symbiosis of two organisms, a fungus and an alga or Cyanobacterium. It is sometimes referred to as blue-green algae. It thrives on a combination of sunlight, carbon dioxide, water and minerals. Lichen will grow in a wide range of temperatures and conditions, from a hot desert to the cold of Antarctica. There are a few different types of lichen but the main ones are the green blue looking lichen and the black streaky algae that attach to your roof.
Lichen can look unsightly on your roof, around your garden paths and on your driveway. It can also cause a hazard on the walk ways of your home. Lichen can hold moisture against the surface that it has attached itself to, and could freeze in cold frosty temperatures, causing damage to the surface. Over time this damage could deteriorate the surface and if the surface is your roof, it could mean any number of things for you as a home owner.
In one of my previous blogs, I wrote about Home Insurance and whether or not you are covered should you need to claim an incident. Upon reading my policy more carefully I found exceptions at the end and it read that if I haven’t maintained my roof and guttering and there is a claim involving them, then I may not be covered for the claim and it would be denied.
So take home lesson here is to keep up the maintenance of your property so that your insurance premium you pay each year is not for nothing.
How can you remove this unsightly Lichen?
Scraping, scrubbing or brushing away lichen could cause the surface paint or protective layer to come away too. The job is time consuming and physical, as it intense labour depending on the pitch of your roof.
There are other ways, for example, metal strips, chlorine bleach or pressure washing. These processes are not without effects from the by-products of the activity.
Metal strips can leave a residue runoff that is harmful to the environment. Galvanised steel, copper and zinc are a natural poisonous substance that inhibits the growth of lichen.
Chlorine bleach residue is also harmful to the environment. It is also corrosive and can cause damage to your gutters, down pipes and flashings. The colour of your roof could change and should you get it on your skin, could cause it to burn.
Pressure cleaning your roof could cause the protective layer to be washed away or the paint to discolour. If there is no sarking in the roof, then water could enter and cause damage. Lichen attach themselves to the crack and crevices and between the tiles and sheets of iron. When pressure washing then top of the lichen is removed but the roots can be left behind in these tight places. It won’t be long before they grow again. Pressure washing your paths and driveways will get rid of the lichen initially but it will grow back, so regular pressure washing will be needed. Old surfaces could deteriorate over time with the pressure of the water flow.
Well what do we do to remove the Lichen?
We use a product that is eco-friendly, killing the lichen without damage to your surface, be it a roof, pathway or driveway. We spray it on and the wind and rain react with the product to remove the lichen.
We need a cool, dry day with no rain in the coming hours after application, approximately four to five hours. This will allow the product to soak into the lichen a provide a more effective job.
The product can take up to 6-12 months to remove the lichen. In cases of heavy areas, second applications may be needed after 12 months but the area will have reduced as the thinner lichen dies off.
Flatter rooves may require a light brushing and then hosing down with a house hold hose to remove the dead lichen after the 6-12 months. Rooves with more of a pitch have the advantage, as the rain and wind and gravity work toward the lichen removal.
Maintenance of your surface after application
Once you have your lichen under control, you may need to spray patches of new growth as it appears.
Areas such as foot paths and driveways that attract moisture, thereby being the breeding ground for moss, mildew and lichen should probably be sprayed once a year to maintain minimal growth.
Black algae lichen spray patch test after 12 months