Remove Moss – Roof Cleaning

The simplest and often the cheapest way to effectively remove moss from a roof is to instruct a general roofing company to physically scrape it off.

You can find out how much it costs to remove moss by visiting this page.

Most local roofing contractors will consider undertaking this type of work. It is something I have done many times and in my opinion is safer and not as messy as pressure washing.

While the contractors are on the roof they can also check for any damaged or broken tiles and replace them. It is also a good time to check the condition of the cement and chimney (if you have one).

After the moss has been removed and the gutters then given a thorough clean out, they can spray the roof tiles with a fungicide moss killing chemical.

Why not consider installing a gutter guard to protect the guttering from leaves and other blockages? Most gutter guards tend to block and clog with bits of roof moss that wash down from the roof. If you first scrape the roof of moss, the guards will work much more efficiently and keep out large leaves.

I have tested various gutter guards here.

How Difficult is it to Clean a Roof by Removing Moss?

Access is the big issue here but in most cases the moss will come off very easily. If the roof is wet it is much more difficult, moss easily turns to mud and it can be difficult to clean a roof in such conditions. It’s always best to carry out this type of work in the summer or at least when the roof is bone dry.

The photos below are from several of my roof moss removal projects. All the moss was removed with a trowel followed by a brush down with a stiff broom. No messy roof cleaning equipment (i.e. water pressure washers) was used on this roof or the hundreds of others I have worked on.

You can see more photos in the Photo Gallery

Here are some tips for roof moss removal:

  • Use the correct access equipment – safety first
  • Carry out this type of work when the roof is dry
  • Start from the top of the roof and work downwards using a trowel to scrape off the moss
  • Then use a stiff broom sweep off any loose moss and dust
  • Replace any broken tiles and clear out gutters
  • Check condition of cement work and repair as required
  • Spray roof with a fungicide moss killer like this to kill off any roots and prevent early re-growth

See More in the Photo Gallery


Roof Cleaning – Should I Use a Pressure Washer?

Using a pressure washer is one way of carrying out roof cleaning work and removing the moss along with any other dirt and grime. However if you have broken tiles on the roof then there is a chance the water may be pushed into the roof.

We do not offer a pressure washing service but feel the moss can be removed adequately by manual methods.

Fragile Clay Tiles

Clay tiles tend to break quite easily and one should avoid walking on them unless it is absolutely necessary. Roof moss removal is rarely a necessary project and even if it is was, I wouldn’t recommend walking on clay tiles, the risk of causing damage is just too great.

In my opinion the best option is to use a long reach pole with either a scraper or wire brush attached to the end and try to remove as much moss as possible without actually walking onto the tiles.

This work could be dangerous if done from a ladder but an access tower raised to gutter height would be perfect. Once the excess moss is removed a moss killer can be sprayed onto the roof, this will kill off any bits of moss and prevent regrowth for a few years.

I would then suggest re-applying the moss killer every 2-4 years to inhibit further growth. This method may seem a little old fashioned but in my opinion it is the only tried and trusted technique that is affordable and doesn’t involve pressure washing. Moss killer chemicals can be purchased in concentrated form, ready to be diluted and applied via a sprayer. They are not too expensive and can be purchased from online stores such as Amazon.


Natural slates are often used as a roof covering, moss can grow on them but tends to occur on the overlaps and joints. It’s quite rare to see a slate roof totally covered in moss.

Because slates are more fragile than concrete tiles and because they are difficult to walk on, I do not recommend climbing onto the roof to scrape or pressure wash the moss off of them. Instead, I would use a long reach pole and try to brush off the excess moss. Then apply a moss killer chemical using a sprayer, these can be purchased from Amazon and have a reach of around 5 metres.


7 Responses to “Remove Moss – Roof Cleaning”

  1. Maureen Johnson03/03/2012 at 5:37 pm #

    I was just looking at details re moss removal. As a former female Roofing Contractor I thought your article was straightforward and honest regarding moss removal. I certainly agree that some unscrupulous roofers would make a big deal of removing the moss. ( and charge over the top for it also). No wonder vulnerable homeowners find it difficult to trust Roofers hence the trade not having a good name.

  2. Spike04/05/2012 at 9:09 pm #

    Nice post. You obviously thought it out well and the photos are really good to illustrate. Im definitely gonna have a look at getting the moss off my roof now, but like you said Ill prob hire someone to do it properly.

  3. valerie skilling19/12/2012 at 11:53 am #

    I noticed a damp spot in bedroom and we had had such a lot ot rainfall this year my husband had cleaned out spouts regularly but not managed to remove moss so I phoned my insurance company Rias about a claim for water damage. The claims surveyor took photos but did not climb onto the roof to inspect just said we had an obligation to keep roof clean ourselves and we could not claim for water damage, is this correct. I have never had moss on roof until this year with all the rainfall and our back street does not get much sun. Is the claims surveyor correct as no one else has ever had to clean their moss before insuring?

  4. Tim Morton25/09/2013 at 7:11 pm #

    Excellent site – very well done
    Pity you’re so far South – need you up in Scotland

  5. John Bossard03/11/2013 at 2:43 pm #

    Absolutely agree with the comment re’ pressure washing. Even with tarpaulin protection on the ground at least 20 feet wide around the house/roof, moss is simply transferred to wherever it lands.
    If you have gravel – then you will soon have moss gravel! And killing that is even more difficult. Killing the ground in gravel moss makes it turn orange/dead, but scraping it ALL up to remove it is virtually impossible.

    However one thought is that – we had moss on our roof for 35 years (when the tiles were first fitted) and OK it had moss, but we only replaced them 6 months ago, basically because we have experience very wet and poor sun summers over the past 2 years and basically as the roof was unsightly, but hey – 35 years! Not bad. And of course the tiles operating life was quoted at about 30 years, so a good time to change them.

  6. Anne17/12/2013 at 5:14 pm #

    Hi, i like this site, its very easy! my slate roof is covered in a fine green down of moss where it is shady but i like it very much, is there any reason to remove moss, does it damage anything.? The roof is well ventilated and not damp or any damage to it.

    • Steven26/01/2014 at 5:48 pm #

      Moss tends to be washed off the tiles by heavy rain and then blocks the gutters.