Mould is a subtle menace that can creep up on our homes behind our backs if we're not paying close enough attention. It's particularly problematic on our roofing, as this slimy black and green substance is not only an eyesore but can lead to serious health risks and as we don't naturally check our roofs frequently, it's something all homeowners need to consciously keep on top of. Thankfully, it's both safe and easy to remove roof mould yourself as long as you have the right tools, a decent amount of patience and you follow the tips below:
Tool Up - For this job you'll need safety equipment (goggles, gloves and a respirator), a good long brush and a ladder, as well as a cleaning solution to get rid of the mould itself. This solution should be made up of around a gallon of water with around a litre of bleach and 60ml of trisodium phosphate. The bleach will kill the bacteria that actually causes the mould, whilst the TSP will take care of the staining.
Safety First - Make sure you don a thick pair of rubber gloves, as well as some goggles and a breathing mask, as the fumes from the chemicals used to remove the mould can be rather powerful, as well as the mould particles themselves. You should also make sure you're dressed appropriately in order to prevent your skin from coming into contact with the mould or potentially harmful chemicals.
Wear long trousers and long-sleeved apparel and strong, slip-resistant boots, as if you have a nasty slip on the roof it can prove devastating. Make sure all equipment is put on before you step foot on the roof and that it remains on firmly throughout the job.
Cover Up - A clever way of making sure chemical runoff doesn't affect the vegetation around your roof is to spray it with a fine mist, which will prevent any harmful chemical elements - from binding to the greenery. Also, be sure to wash them afterwards and if you are really concerned then tarpaulin is your friend.
Safety Second - In any situation where you're using a ladder, make sure it's well supported on a piece of flat and stable ground - concrete and stone if possible. If you can, convince a spotter to help you out and keep the ladder stable whilst you climb.
Also remember to take your time, particularly on a pitched roof that might be steeper than it looks. Always ensure your footing is secure before putting your whole weight down and try and stay within the ridge section of the roof as this will be the safest section.
Scrubbing and Spraying - Start by using a brush to scour the surface of your roof shingles to loosen the mould up as much as possible, starting with the areas where it's really dense and difficult to reach.
Next, take your roof cleaning solution and use a sprayer to disperse it evenly over the roof, making sure that the heavily affected areas get a little more than the rest. Start at the bottom and work your way up to the top to prevent the chemicals from draining towards you.
Rinsing Off - Let the cleaning solution sit for around 20 minutes and do its thing before returning with either a pump sprayer of water or the garden hose to rinse the roof down. If not rinsed properly, the bleach might be strong enough to leave a nasty stain. Make sure the entire roof has been washed clean.
Note, it's always best to undertake this job when it's not too hot, which can lead to evaporation, and there is no chance of rain. Also, clean your roof at least every couple of years to prevent mould from growing again - or consider switching to mould-resistant shingles, made from zinc and copper, or installing zinc and copper flashing to stop it in its tracks 100%.
If you are in any doubt, contact your local professional roofing company and they should be able to offer some sage words of wisdom. Failing that, there's always YouTube!