04 May Moss related roof problems

Mosses won’t kill you, but they can cause multiple problems for a roof.

We’ve seen first-hand how moss can clog and bring gutters down, and how it can grow behind pointing and lift it away, causing a leak. By no means is having moss on your roof a crisis, but it is something that needs dealing with.

Here’s why:

Moss keeps your roof wet

Mosses grow in dense clumps and grow fast after taking hold. The issue here is not the appearance of the moss but the fact it absorbs moisture and keeps hold of it. In doing so, on a roof it means the roof is constantly wet in places. Eventually, that moisture can penetrate the tile, and this is especially true if the tile is cracked. If moisture gets underneath the tile it could enter your property and rot the timber.

Moss impedes drainage

The whole point of your roof having a pitch is so rainwater can flow and run down it into your gutters. If you have moss on your roof, the moss will obstruct the water’s path and slow the process down. This is an issue because a roof needs to drain. If it can’t drain, it will eventually succumb to water penetration.

Moss attracts birds

Have birds on your roof, pecking away at the tiles? They’re not there for the tiles – they’re there for the moss and the insects living in it! This is an issue because birds tear off the moss which then falls down the roof into your gutters, clogging them. Birds also chip away at pointing if there’s moss growing on it. This wears the pointing down and can lead to cracks which allow moisture to penetrate your building.

Moss will clog up your gutters

If it isn’t birds pulling it off, moss will find its way into your gutters anyway. It has to eventually – after all, what is up must come down. Moss degrades slower than grass and has a lump of dirt at its base. This dirt is what clogs up your gutters. It’s an issue than needs remedying because it won’t remedy itself – mosses actually thrive in gutters because they’re wet, so don’t allow them to grow.

What to do with moss on your roof

Moss should be removed from your roof periodically. As with weeds, you can’t eliminate it for good, but you can keep on top of regrowth.

Follow this three-step process to get rid of moss on your roof:

1. Firstly, you should brush off the moss and remove any waste from your gutters. This will eliminate the immediate problem.
2. Secondly, spray a specialised moss killer onto the tiles. Use a moss killer that is not harmful to the immediate environment. You needn’t worry about your garden below because the moss killer will run off into your gutters when it rains.
3. Thirdly, reapply the moss killer 6 weeks later. This will ensure the moss doesn’t regrow and you have covered all areas of your roof. It is also good practice to spray your gutters so growth cannot reoccur here.

Monitor your roof and check back on it every month. In the winter, you may find some regrowth occurs. It is best practice to follow this process after winter in dry weather and to repeat the steps come summer.

If you would rather have a professional deal with your moss problem, we’d be happy to. We’ll inspect your roof from top to bottom, identify any issues such as cracked tiles, and remove all moss from your roof. Call us on 0800 9788 168 to get started.