Roof Cleaning & Moss Removal

A lot of people will tell you that moss and lichen on a roof will permanently damage the tiles. Personally I do not think that is entirely true, but there is no doubt that this can look unsightly and cause problems as the moss falls off, blocking gutters and downpipes, plus leaving a mess on the surrounding paths and patios as the moss is disturbed by birds and wind throughout the year.

How to Clean a Roof


Simply scrape the moss off the roof.


  • Very little equipment needed
  • Relatively quick & simple

  • The moss will grow back very quickly
  • Most of the general debris will not be removed
  • None of the lichen will be removed


Simply apply biocide

Note: We offer this service if a roof is in a poor condition, with lots of loose tiles and would not be able to take any physical contact from any form of cleaning tools.

  • Very quick & cheap approach

  • The moss will slowly die and in doing so fall down the roof, blocking your gutters & downpipes, leaving a mess around the property


Scrape the moss off, then apply a biocide or chemical (soft wash).
This is not a bad solution, the moss is physically removed and the biocide kills the moss roots & lichen.

Note: We offer this service if a roof is in a poor condition, with lots of loose tiles and would not be able to take any physical contact from any form of cleaning tools.

  • Very little equipment is needed (why some window cleaners offer this service as they already have the tools).

  • Does not remove the grime that has built up over the years that has turned most roof tiles black, but the biggest drawback is it can take months for the full effect of the chemical to work.

The Pressure Elite Approach

We will clean your roof without anyone having to clime onto it, we access your roof using long reach carbon fibre poles, and by standing on an aluminium scaffold tower placed close to the building so that we can reach every part of the roof.

As for the actual cleaning, over the years we have found the following description to be the best approach for a roof that has tiles or slates that are in a sound condition.


We disconnect all of the gutter downpipes to avoid blocking any drains, if the house has planting up the walls or if it has a gravel path or driveway, we first lay down a fine net over the area to assist in the clean up operation.


If the roof has a carpet of moss on it that you sometimes find if the roof is in the shade most of the day, i.e. under a tree, we scrape the bulk of the moss off of the roof to ease the cleaning process.


We will clean the roof using low-pressure water at around 70 bar (approximately 1000 psi).

This may sound high, but when you remember that a little pressure washer such as a Karcher K5 or K7 used for home car cleaning works at a pressure between 2000-2600 psi, you can see a 70 bar system will not harm a roof tile.

Our system is not the same as using a normal pressure washer with a single jet as we use a multi-jet, flat surface cleaner & fanjets which are always sprayed down the roof.

This cleaning process removes not only the moss, but all of the debris and grime that has accumulated over the years, leaving your roof looking extremely clean.

What is has not done is remove the moss root system that has found its way under the gaps between each tile, or the lichen on the tiles as no amount of water pressure can remove them, this is achieved in the next operation.


We will now apply a biocide to kill off all of the remaining moss root system, and the lichen that has been left attached to the tile, this lichen will disappear over the coming months.

Note: We never spray any chemical onto a roof, although many people do apply them in this manner. In our view this approach is irresponsible as particles of the chemical become airborne, which is not very good for us, but also bad for the environment.

We apply the biocide through a brush system, the chemical as also mixed with a surfactant which forms a foamy sticky solution that clings to the roof, this way very little liquid ever reaches the gutter.

Play Video

Biocide Application


All of the gutters will be cleaned and washed down.

There is no getting away from the fact that this can be a messy operation, one of the largest part of our work is to ensure that your property is completely washed down and all surrounding paths and gardens are left clean & tidy, to achieve this we will wash down all of the walls and windows with a low-pressure, high volume water spray.

This is no D ionised water that a professional window cleaner might use, so some streaking may be left of the windows, that is why we always recommend a visit from a professional window cleaner after we have visited.

There are always pros & cons to a cleaning system

Here are our pros…

  • The Roof is left free from any grime or lichen.
  • The biocide has some residue properties making it much harder for the moss to re-establish.
  • The roof is left looking completely clean with nothing to fall off and block gutters, or fall onto paths and patios for the years to come.

The cons?…

  • It takes a lot longer for us to complete the work.
  • A lot more equipment is needed.
  • It creates mess, but we do clean it all up.

To Sum Up

You can simply scrape the moss off of your roof, but if you want to be left with a clean, new looking roof that will stay that way for many years, we think that the small difference in price in our system is a sound investment.

Natural Stone & Man Made Patios & Paths

We can normally bring stone patios and man-made slabs back to an almost new appearance.

This is achieved using high-pressure water through a flat surface cleaner to remove the surface grime.

The big problem with a lot of patios and paths is the colonisation of various forms of lichen, the most difficult and one of the most common being known as black spot due to its appearance.

This form of lichen is almost impossible to remove using high-pressure water alone as the lichen has attached itself deep into the paws of the stone or concrete slab.

It can however be removed chemically. We always keep chemicals with us that can remove this growth and your lovely stone patio can be restored to former glory.

national stone

Block Paving, Patios & Driveways

Block paving has become very popular over the years, it looks clean & sharp when it is first laid but after years of use it can start to look dull & uninteresting. We can however, bring back most block paving areas to life again.

By first using our large flat surface cleaner to remove the surface grime, followed with the assistance of high-pressure fanjets to remove any stubborn stains and moss. With the surface now free from grime and moss growth we would apply a solution of sodium hypochlorite, this kills off all of the lichen and other growth that has attached itself to the blocks over the years.

We the wash down the whole area again and remove all the debris from the surface.

Your block paving drive will now look like new!

Stonework & General Building Cleaning

This is an area of cleaning that can vary enormously, it can also become very specialised, and we know our limitations due to the equipment we operate.

However, we have been very successful cleaning large stone buildings, using a low-pressure hot water system, mixed with a chemical to breakdown the traffic carbon and general grime that has built up over the years. We then use a soft water system to kill off all of the organic growth. This system transforms the appearance of old stone and brick buildings.

Timber Decking

Timber decking needs to be cleaned very gently. Using a conventional pressure washer will damage the surface structure of the wood.

We will always use a low-pressure system and then apply biocide to kill of all of the green growth that has gotten deep into the surface of the timber.

After the cleaning process has taken place the decking needs time to dry and then one of the many oils that are available on the market needs to be applied. We can apply this for you, but it is far more cost-effective for the client to do this themselves as it is very simple to apply.

HGVs, Plant & Machinery

Pressure Elite is involved in the ongoing cleaning on many local businesses, we clean HGVs before they go to ministry testing.

We have clients that buy and sell plant and machinery, who always want it cleaned ready for sale, as no matter how old equipment might be, it always fetches a better price when clean.


Local farmers use our cleaning services to keep their livestock trailers clean and hygienic, or just to help them keep on top of the cleaning of all of the general agricultural equipment.

We also help local dairy farmers keep on top of the cleaning of their milking parlours.

For a free, no obligation quote, please get in touch today.