How to Clean Moss Off Your Roof

What You'll Need
Pressure washer
Extension hose (if necessary)
Garden trowel
Chisel or putty knife
Safety glasses

Moss removal from your roof is more of an inconvenience than it is a difficult job. Because some roofs can be very steep and access to them can be somewhat of an ordeal, cleaning moss off of them requires a little bit of planning, in order to complete the job  quickly and effectively. Full scale roof repair is a job that, if you are working alone, could take weeks. Moss removal is not as time consuming provided you have the right tools and a few hours to spare.

Step 1: Position the ladder

There is no need to erect scaffolding in order to clean moss off of a roof. However, depending on the pitch of the roof, simply climbing atop it may not be such a good idea. Positioning a ladder is your best bet, but, depending on the height of your house, you might need a fairly expansive ladder. Assuming the ladder you have reaches the eaves, position it in such a way that it stands securely on both legs. It would be better if you had a spotter on the ground for added support. Stand the ladder as close to the mossy area as possible.

Step 2: Pressure wash

If the pressure washer requires an extension hose to reach the roof, install it. Attach the water line, turn on the pressure washer and climb the ladder with the nozzle. Always wear safety glasses. Try not to blast the roof with full power as you could inadvertently shoot water underneath a shingle. If you can, aim the water from the side to blast the moss off without letting any water seep in.

Step 3: Scrape off any remnants

With a chisel or putty knife, scrape off any tough mossy remnants left behind by the pressure washer. You’d be surprised how resilient moss growth can be. Be careful not to gouge out any holes in the shingles.

Step 4: Clean out the gutters

Chances are quite a bit of the moss you blasted or scraped off will end up in your gutters. With the garden trowel or any scoop-like tool, remove the bulk of the moss that has accumulated in the gutters. If the downspouts are not connected to a sewer, you can set your normal hose nozzle on jet and flush the smaller pieces down the gutter onto the ground. Be warned: if you try to wash the big pieces down, they could get stuck.

Roofs of differing heights and obstacles such as trees or power lines may present some trouble, but aside from that, the process is a matter of getting to the moss and blasting it off with a high powered jet of water, followed by scraping and rinsing out the gutters.