Roof cleaning - the need to knows

Your home is likely the most expensive investment you'll make. Naturally you want it to look it's best, but also you want to protect it. More and more surveys and Home Reports are mentioning roof moss and the need to remove it, but why?

Moss thrives in the cool. dark climate we have in the north of Scotland. It tends to grow on Northern and Western facing roofs that see less sunlight, beginning at the vertical joints and along the front edges of the tiles. As it grows, moss can weave its way between and underneath the tiles. Moss can hold up to 30 times it's own weight in water which can then find its way into the roof structure. Over winter the moss expands as it freezes, further widening any gaps created between the tiles.

Roof moss is also a favourite of birds, either to use for nest building or to forage inside for grubs. Any moss that becomes loose falls into your gutters and I'm sure we've all seen bits of moss that have fallen onto the ground. While it's annoying to have to constantly sweep up at ground level, the main problem can be in the gutters. Moss will often block downpipes and impede the flow of water along the gutter itself. The added weight this causes can often lead to leaks and breakages.

SO WHAT CAN DUNCLEAN DO TO HELP?

In a nutshell, we safely remove the moss and treat the roof to inhibit the regrowth for several years. This is done using specialist tools to allow us to gently scrape 90% off the moss away while standing on a scaffold tower or at ground level. This is important as it means there is usually no need to stand on your roof. Doing so can weaken and damage the tiles and is also much more dangerous for us. The specialist treatment we use takes care of any little bits of moss growing into the tiles and also works to kill any lichen. algae, and biofilm that may also be growing on the roof.

ARE THE RESULTS INSTANT?

The scraping action itself and the removal of moss can make the roof look a lot cleaner. The treatment begins to work within hours and has generally killed any remaining fragments of moss within a couple of days. Mother nature does the rest. Moss crumbles and turns to dust while the lichen and biofilm slowly dies and begins to detach from the roof after a few months. The full effect of the treatment can take up to 12 months depending on the climate.

There are other treatments that can be considered depending on circumstances. These can be much faster acting but generally only last for several months. A combination of treatments is sometimes used, these would require a follow up visit and take a lot more work.

IS THE TREATMENT HARMFUL TO THE ROOF?

No. It has a cationic action which means it only reacts with living matter. An initial inspection of the roof material will assess cleaning options. The treatment is brushed onto the roof which improves results and limits any overspray or flooding of the roof.All downpipes are blocked off to prevent any excess treatment getting into the watercourse. The treatment we use is fully licenced for use in the UK and EU as well as being fully HSE label compliant.

WHY DON'T YOU JUST USE A PRESSURE WASHER?

The major roof tile manufacturers (Marley & Redland) caution against pressure washing a roof. In the wrong hands water can easily be forced under the tiles causing damage and leaks. High pressure also removes the waterproof coating on the surface of the tiles. Pressure washing is also the most dangerous form of roof cleaning as it usually means walking on a slippery roof while trying to control a jet of water.

If somebody is working on a roof for a prolonged period of time (other than to action minor repairs) then they should be fully trained in rope access and using correct harnessing equipment. Failure to do so can invalidate insurance policies and leave the property owner liable for any damage or accidents.

DO YOU DO ROOF REPAIRS?

No. We are not qaulified and would always reccomend calling in a local roofing company if we come across any damage. Becaise we don't walk on the roof there is very little risk of us causing damage. We inspect the roof while standing at gutter level before we carry out any work as well as taking before and after pictures so we can advise you pf any repairs we think may be needed.

HOW LONG DOES THE WORK TAKE?

This will depend on the size of the property. For a standard 3-4 bed house we would normally allow 2 days to complete the work. This is always advised before work starts.

HOW LONG WILL THE RESULTS LAST?

We cannot guarantee results for a specific period of time but as a general rule it will take about 3 years for moss to begin to grow again. It can then be several years after that before full moss removal is required again but prevention is always better than cure,

WILL THERE BE A MESS?

The moss is scraped off the roof onto tarpaulin sheeting and gutters are emptied. It is then all bagged and taken away with us, leaving no mess behind. Moss is organic and can be very good on compost heaps or spread directly onto garden, just let us know if you'd like any left behind.

Moss build up can lead to problems on a roof and decrease the life expectancy as well as being unsightly and the cause of constant sweeping up. As mentioned above, there is a solution. For more information or to request a quotation get in touch with your favourite exterior cleaning specialist.