How Much Does Roof Cleaning Cost? (2026 Guide)

What roof cleaning costs

Most homeowners across Northeast Connecticut, Worcester County, and Rhode Island pay $400 to $750 to have an average single-family roof professionally cleaned. A small ranch roof can come in around $300. A large, steep, or heavily stained roof runs $900 to $1,500.

Roofs are priced by squares, which is roofing shorthand for 100 square feet of roof surface, not floor area. A steep roof has considerably more surface than its footprint suggests, which is why two houses with the same square footage can quote very differently.

We quote flat, up front, from photos. Text 2 or 3 pictures to (860) 553-9326 and you will usually have a number back within the hour, and that number does not change when the truck shows up.

Those black streaks are alive

The dark streaks running down the north side of almost every asphalt roof in New England are not dirt, soot, or shingle wear. They are a blue-green algae called Gloeocapsa magma.

It feeds on the limestone filler that manufacturers blend into asphalt shingles, and it spreads by airborne spores, which is why once one house on a street has it the neighbours follow. It holds moisture against the shingle and it slowly loosens the protective granules that keep UV off the asphalt mat underneath. Left alone for years it shortens the life of the roof.

It also almost always shows up on the north-facing slope first, because that side dries slowest.

Moss and lichen are worse

Algae stains. Moss does damage. Moss holds water like a sponge, lifts the bottom edge of the shingle as it grows underneath, and in a New England winter that trapped water freezes and pries the shingle further open. Lichen is the toughest of the three, because it puts down root-like structures that grip the granules and will not release without a proper detergent dwell.

None of the three should be scraped, brushed, or blasted off. All three come off chemically.

Soft wash, never pressure wash

This is the part that protects your money. A roof should never be cleaned with high pressure.

The Asphalt Roofing Manufacturers Association, the trade group for the companies that manufacture your shingles, recommends cleaning asphalt shingle roofs with a low-pressure chemical wash. High pressure blasts the granules off the shingle surface, and granules are what stops UV from cooking the mat. Losing them takes years off the roof, and shingle warranties routinely exclude damage caused by improper cleaning.

A soft wash applies a biodegradable detergent at roughly garden-hose pressure, lets it kill the growth on contact, and rinses. Nobody walks the roof any more than necessary, nothing is scrubbed, and the result keeps working for months as the dead growth weathers off. There is a fuller explanation in our guide to soft washing vs pressure washing.

What moves your price

Size and pitch

Squares first, then pitch. A walkable 4/12 roof is straightforward. A 10/12 roof means everything is done from ladders and poles, more slowly and more carefully, and it prices accordingly.

How much growth there is

Light streaking on one slope is a single pass. A roof carrying heavy moss on the north side and lichen along the shaded ridge needs more product and more dwell time.

Height and access

A three-story wall with no room for a ladder, a screened porch in the way, or a septic field we cannot drive across all add time.

Landscaping around the house

Everything that comes off a roof lands in your beds. We wet down the plantings before we start and rinse them again afterward, and the more there is to protect, the more prep time the job takes.

What else you book at the same visit

Roof runoff lands in the gutters and on the siding, so nearly everyone books gutter cleaning and a house wash at the same time. Bundled, it costs less than three separate trips. The right sequence for the whole property is laid out in our guide to exterior house cleaning.

What happens on the day

• We walk the property with you and confirm the plan
• Beds, shrubs, and anything sensitive get soaked with plain water first
• The detergent goes on at low pressure, slope by slope, and is left to work
• Everything gets rinsed, including the landscaping, a second time
• We walk the property with you again before we leave

Most roofs are a half-day job. Heavy moss can look better immediately and keep improving for weeks as the dead growth washes off in the rain, which is normal and expected.

How often should a roof be cleaned?

In our shaded, humid climate, most homes want a roof cleaning every 2 to 4 years. North-facing roofs, homes under heavy tree cover, and anything near water sit at the short end of that. Wide open, sunny, breezy lots stretch further.

If you are on that cycle it is a maintenance wash, which is quicker and cheaper than a rescue job on a roof that has gone fully black.

Cleaning versus replacing

This comes up often, usually because somebody has told a homeowner the roof looks finished when it is only stained. A roof at eight or ten years old covered in black streaks is very rarely worn out. It is dirty. Cleaning is a few hundred dollars, a replacement is many thousand, and the cleaning also stops the algae from continuing to work on the granules.

If shingles are curling, cracking, or missing, that is a different conversation and you want a roofer, not us. We will tell you that when we look at the photos.

Signs it is time

• Dark streaks running down the slope, worst on the north side
• Green fuzz or clumps of moss along the shingle edges or in the valleys
• Crusty gray or pale green patches, which is lichen
• Granules collecting in the gutters or at the bottom of the downspouts
• Neighbours' roofs going black, because it spreads by spore

Get a flat quote

Applewood Exterior Cleaning soft washes roofs across Northeast Connecticut, Worcester and Middlesex counties in Massachusetts, and all five Rhode Island counties. The full list is on our service areas page.

We are owner-operated. Two of us, both raised in Pomfret, and one owner is on every job, which on a roof matters more than anywhere else. We carry general liability and workers comp and send a certificate of insurance before work starts. If anything is not right we come back within 30 days, and if the growth returns inside the year our 365-day guarantee covers it.

Text 2 or 3 photos of your roof to (860) 553-9326 and we will send back a flat quote, usually within the hour. Or read more about our roof cleaning service.