Roof Cleaning is the one part of property maintenance which is most often overlooked. We mow our lawns, trim hedges and bushes, keep the yard clean, all on a regular basis but when it comes to the roof, that tends to get left until it becomes so unsightly, you just can’t leave it any longer.
Aucklands’ climate is ideal for encouraging the growth of micro-plants on all forms of roofing materials. – Lichen, algae, mildew, moss and moulds thrive and when ignored they become quite unsightly. In a relatively short space of time your roof begins to resemble a forest floor displaying varying patterns of “natural” colours.
What many home owners don’t know is that these plants secrete destructive acids that weaken the composition of roofing materials. Rust can form on metal surfaces and that will be hard to detect because of the growth. Also, small creepy crawlers and fliers that eat and prefer the moist composition of lichen, moss and moulds may be encouraged to make your roof their home and they can also cause damage.
Roof Cleaning is definitely necessary and highly recommended but the method is in question. We DO NOT recommend Roof Cleaning using a water blaster unless absolutely necessary.
There are several reasons why an Auckland home owner might consider using a water blaster to wash the roof:
- You’ve ignored the roof for so long that you now need an instant clean – before your overseas guests arrive.
- To brighten up the property or to enhance ‘Kerb Appeal’ prior to selling.
- To remove moss and lichen that has built up on the tiles.
- In preparation for a roof coating, a repaint or the application of a special sealant.
Whatever your reason is – Water-blasting should not be your first option.
Our View On Roof Cleaning
While we do encourage roof cleaning, we actively attempt to dissuade our clients from water blasting the roof unless it is absolutely necessary. Particularly when dealing with tiled roofs.
Water blasting is NOT the best option when it comes to:
- Concrete Tiles
- Clay Tiles
- Decramastic (Stone Chip)
Roof Cleaning Without The Need For Water Blasting.
The most gentle way to remove roof moss, mould and lichen is by way of good old-fashioned hard work. You have a couple of options but the most effective is ‘scraping’.
A small wire brush works well on concrete and clay tiles but I wouldn’t recommend you use them on painted surfaces. If you choose a dry day then the moss and lichens will flake off the roof much easier. This approach may involve some hard graft but if you’re comfortable working on a roof then it is a very inexpensive method.
The preferred method is to apply an effective Moss, Lichen and Algae remover to the entire roof and let the weather remove the debris over a period of time.
If you are looking for a quicker solution – then after the chemical has been applied and you can see the Lichen and Moss has died, (usually noticeable after a week or so) then you can brush down the whole area using a standard yard broom.
With scraping, there is no damage to the tiles and no flood risk.
On the left, you can see a commercial grade Roof Treatment being applied. This is a very cost effective Roof Cleaning method which is much more gentle on the roof surface.
Roof Treatments: A commercial strength ‘Moss, Mould and Algae Remover’ is applied at very low pressure. The efficiency of this method is reliant on knowing when to apply the treatment. The chemical needs enough time to soak into the surface and any moss, mould, lichen and algae that are present will immediately begin to die off.
Done properly, we can then rely on the weather to remove the debris over a period of time. This process can take anywhere from 6 months to a year depending on how bad the problem was to begin with. To keep your roof looking good this treatment should be repeated every couple of years. Some say it should be done annually but in our experience every second year is fine.