Should you Remove Moss from your Roof: A Cleaning Guide + Tips!

If your roof has a large area that’s covered with moss (or algae/mildew/lichen) then giving your roof a good clean is undoubtedly something to consider.

As well as looking unsightly, a large build-up of moss can actually reduce the roof’s ability to function and its lifespan. It can also cause decay in the shingles and any other wooden fixtures that you may have. If a large amount of moss gets into your guttering, then that’s another problem in itself!

Psst: Are you looking for a Roofer in Trowbridge? I am often in the area and happy to swing by and give a no obligation quote to repair or maintain your roof.

If you have decided to go ahead and remove the moss from your roof, there are a few things you can do to make your life – and the removal of moss – a lot easier:

  1. Dead moss is easier to remove! When moss is wet, it sticks to everything and is time-consuming to remove. Dead moss is dry and will be much easier to scrape off.
  2. Jet-washing is a big no-no! It might seem like a great idea to get up a ladder and blast the tiles with water but don’t! Using a jet-washer will most likely cause damage to your tiles and crack/break them, as well as the risk of drenching the lining underneath or flooding your loft space.
  3. Baking Soda is a very effective, natural – and cheap! – product to use. When mixed with water and applied directly to any patches of moss, it will kill it off as moss needs a pH environment of around 5.0-6.0 to thrive and the alkaline solution will alter that.
  4. If you choose to purchase a product – and you have wooden shingles – ensure you choose one that does not contain any chlorine bleach. Chlorine will cause the wooden shingles/fittings to curl and therefore shorten their lifespan.
  5. Fungicides can also be used; be sure to purchase one that’s mainly for moss/lichen/algae.) If you also have delicate roof tiles (and some are already cracked) then a home-mixed remedy might be your best option.

Once you have applied your chosen cleaner, you should be able to gently scrape off any moss. Simple tools such as a trowel and a hand brush will get the job done. Hanging a bucket from your ladder will also provide a great place to collect any gathered moss. You could just fling it off on to the ground below, but then you’d have to sweep that up!

When you consider that the cost of hiring a professional to clean your roof is going to be several hundred pounds (for a standard semi-detached house), it is worth considering cleaning it yourself. If done thoroughly, your roof should stay moss-free for at least 3 years. After 4 years, you will probably start to see light regrowth.

If you are thinking of applying a moss-killing chemical, this will need to be done *after* any moss has been removed. If you attempt to apply it before removing any moss, you will need a lot of product to soak through it all, and the moss would likely just soak it all up! If you then left the dead moss to just fall off, you would end up with blocked gutters.

Therefore, to recap, the best thing to do to remove moss from your roof is to apply your chosen moss-removing remedy, scrape away any dead moss and then apply a moss-killing chemical.

I would also recommend that you do not clean your roof regularly just to keep it looking clean. Spring cleaning your roof more often than necessary will reduce the life of your tiles and can do more harm than good. Every 3 years is just fine! If you cannot carry out this task yourself, then I am happy to provide you with a quotation.