If the shingles under the moss are still flat, solid and holding their granules, then yes, roof cleaning is worth it. It costs a small fraction of what a new roof does and can buy you years of extra life. If the shingles are curling, cracking or worn bare, cleaning won’t bring them back, and that money is better spent on a replacement.
Most homeowners in Olympia, Lacey and Tumwater fall somewhere in between, which is why so many people ask whether roof cleaning is worth it. Below is how to figure out which side of the line your roof is on. If you’d rather have someone take a look for you, you can read more about our roof cleaning service in Olympia.
Does cleaning a roof make it last longer?
Yes, as long as the roof is still in reasonable shape. Moss holds water against your shingles like a wet sponge. In a place that gets around 50 inches of rain a year, that means the roof barely gets a chance to dry out between October and April.
As the moss gets thicker, it creeps up under the bottom edge of each shingle and lifts it. Rain then gets pulled up and underneath, where it was never supposed to go. A few winters of that and you start seeing loose granules, raised tabs and, eventually, rot in the wood decking below.
Asphalt shingles are usually rated for 20 to 30 years. A roof that spends most of that time under a layer of moss often doesn’t make it to the low end. Getting the moss off, and keeping it from growing right back, gives the shingles a fair shot at reaching the age they were built for.
Is cleaning worth it compared with the cost of a new roof?
Replacing an asphalt roof on a typical Thurston County house usually runs into five figures once you add up tear-off, disposal, new underlayment, shingles and labor. A steep pitch, more than one old layer or rotten decking will push that number higher.
A professional cleaning costs a small percentage of that. You could have a roof cleaned several times over its life and still spend far less than one replacement. The exact price depends on the size and pitch of the roof and how much growth is on it, so the quickest way to get a real number is to ask for a quote on your house. For most homeowners, that price gap is the main reason roof cleaning is worth it.
When is a roof too far gone to clean?
Cleaning can’t undo damage that’s already there. Before you pay for it, take a look from the ground with a pair of binoculars, or from a ladder if you’re comfortable up there. These are the signs that point toward replacement instead:
- Shingles curling up at the edges or cupping in the middle
- Bald spots where the granules are gone and the dark mat shows through
- Cracked, broken or missing shingles across large sections
- Decking that feels soft or spongy underfoot
- Water stains on a ceiling, or damp insulation in the attic
- A roof that’s already 20 or more years old
One or two of these in a small area might only need a repair. If you’re seeing several of them across the whole roof, a cleaning will just make an old roof look nicer for a while. Get a roofer’s opinion first. If they tell you there are good years left in it, that’s exactly when roof cleaning is worth it.
Keep in mind that thick moss can hide problems. Ask whoever cleans your roof to point out anything they notice once the surface is clear.
Does moss void a shingle warranty?
It can. Shingle warranties generally cover defects in the product, not damage caused by a lack of upkeep. Many manufacturers list moss, debris buildup or poor maintenance as reasons a claim can be turned down. The details change from brand to brand, so dig out your paperwork or look up your manufacturer’s warranty online.
How the roof gets cleaned matters too. The Asphalt Roofing Manufacturers Association advises against pressure washing asphalt shingles, because too much pressure can strip off granules and shorten the life of the roof. Before anyone climbs up, ask how they plan to clean it.
What about the gutters?
All that moss has to go somewhere, and a lot of it ends up in your gutters. Dead moss, granules and fir needles pack together into a heavy, wet mat that blocks downspouts. Once that happens, water spills over the side and lands right next to your foundation, which can lead to leaks, cracked foundations and mold.
If you’re having the roof done, plan on gutter cleaning for your Olympia or Lacey home at the same time. It’s the easiest way to make sure the mess from the roof doesn’t turn into a new problem at ground level.
Is roof cleaning worth it for your home?
For most homes in the area with a roof under about 20 years old and moss that hasn’t caused structural damage, it is. You’re spending a modest amount to protect something that costs a great deal to replace. For an older roof with curling or missing shingles, put that money toward a new roof and keep it clean from the start. Zach’s Power Washing cleans roofs throughout Olympia, Lacey, Tumwater and Thurston County. Call 360-915-3282, Monday to Saturday from 9 am to 5 pm, and tell us what you’re seeing on your roof.
