Average Roof Cleaning Cost Per Square Foot

Cleaning a roof costs $0.20 to $0.60 per square foot. Many contractors charge by the square foot of the roof or by the square. Each square is 100 square feet, and the average house has 17 squares.

Cost to Soft-Wash a Roof

Roof Stain Removal Prices

The cost to remove stains depends on the cause. Most roof cleaning products loosen dirt and algae, and usually come included the estimate. Other stains, like salt buildup, take longer and may add an extra $50 to $100 for the time.

Pressure-Wash Roof Costs

Most contractors don’t recommend pressure-washing or power-washing a roof. This is because the water comes out too forcefully and can damage the material. Instead, soft-washing with a garden hose is least likely to chip, dent or crack the tiles or panels.

Pressure-washers use 1,300 to 2,800 pounds per square inch to strip dirt, moss and even paint from a surface. By comparison, a fire hose sprays at 150 to 300 psi. The average garden hose sprays water at 40 to 80 psi.

Roof Moss Removal Cost

Removing moss and algae buildup may be part of the total cost to clean a roof, or it can be an added expense. These accumulations can:

• Block the gutters
• Absorb heat, which increases cooling costs
• Keep shingles wet, which may cause them to wear out sooner

Most of the time, a roof contractor can remove it by hand or with water. Many cleaning products can also help loosen or dissolve moss, algae or lichen.

Roof Moss Treatment Cost

After moss removal, roof cleaning pros usually recommend that you add a treatment to keep it from coming back. This may cost an additional $100 to $200.

Roof Washing Prices and Methods

Roof cleaning pros charge about $425 for all roof types. Although soft washing is the best approach, contractors use different solutions for asphalt vs. tile or metal.

Cost to Clean Roof Asphalt Shingles

Cleaning asphalt falls into the same range of $300 to $575. The soft, flexible shingles require a delicate cleaning approach. High water pressure can deteriorate or remove them. Soft washing with a biodegradable product removes most accumulations without damage.

Roof Tile Cleaning Cost

Roof tiles average $425 to clean. These materials can last much longer than asphalt, but take extra care to clean without damage. Tiles made of ceramic, clay or concrete were not meant to support human weight. Hire an experienced pro to help make sure that your project doesn’t turn into a repair job.

Ceramic Tile

Ceramic tile may be the only type that can handle pressure-washing, due to its dense composition. Most pros still don't recommend it. To avoid damage, it’s usually better to soft-wash it with a roof cleaning product.

Clay Tile

Clay tile is a lot like ceramic, so the cleaning methods are similar. Clay is more porous, so it can’t take pressure-washing. Instead, you can use a garden sprayer with a product like Roof Wash.

Concrete Tile Roof Cleaning

Concrete tiles are popular in temperate climates with wet weather. Moss buildup is typically the biggest problem for this material.

Metal

Metal roofing won’t chip or crack like tiles, but the panels can scratch or dent. Plain water with a mild liquid detergent usually works well.

Slate

As with metal, cleaning slate involves water and a small amount of liquid detergent. The tiles are heavy but can crack if someone steps carelessly.

Tar and Gravel

Cleaning a tar and gravel roof usually requires water and a solution that eliminates mold and mildew. Pros may use bleach, but it requires care to avoid damaging plants nearby.

Wood

Wood roofing can blow off under high pressure, so you’ll want to use a garden hose. For stubborn stains, pros often use deck cleaning products. Solutions containing oxalic acid may be rated to work with cedar shakes.

Rubber Membrane Flat Roof

If you want to clean a rubber membrane flat roof, you’ll need liquid detergent, water and a scrub brush. Significant dirt buildup may require a special product for rubber.

Roof Cleaning Cost Factors

The $425 average to clean a roof depends on several factors, including:

• Extra services, like coating
• Frequency
• Size
• Height and location

Roof Cleaning and Coating Cost

The cost to coat a roof averages $975, on top of the $425 price to clean. Coating seals the material, which helps repel water and reflect sunlight.

Time Since Last Roof Washing

How often you clean the roof affects the price. Yearly service usually costs less than waiting 10 years.

As a general rule, you’ll want to clean your roof every 1 to 2 years. If you live in a humid area with lots of rain, you may need to schedule service once a year.

Roof Size

The average home has about 1,700 square feet of roof to clean. If yours is larger or smaller, that may affect the charge.

Pitch and style also affect the price. Cleaning a steep roof or one with lots of gables may add an extra $0.15 per square foot.

House Height & Location

Roof cleaning prices assume a one-story home. Plan to add about $0.10 per square foot for a second or third story.

Location and climate may increase cost, as well. Salt buildup in coastal regions takes longer to remove.

DIY vs. Hiring a Roof Cleaning Professional

Hiring a pro to clean your roof is almost always the best choice. A contractor can:

• Safely navigate the surface
• Avoid breaking delicate tiles or shingles
• Use the right products for the material

When you’re ready to find roof cleaning services near you, be sure to get at least three quotes and ask about experience.

FAQ

How much does roof shampoo cost?

Roof Shampoo is a biodegradable cleaning solution that isn’t sold directly to homeowners. To get an estimate, contact an authorized contractor in your area.

How much does it cost to pressure-wash or power-wash a roof?

The cost to pressure-wash or power-wash a roof runs $425 on average. Most contractors don’t recommend it.

Is it safe to power wash a roof?

In most cases, power-washing a roof can damage the material.

Is roof cleaning necessary?

Regular roof cleaning can extend the lifespan by 10 to 20 years. You may not need to do it every year.

How long does it take to clean a roof?

Cleaning a roof takes 2 to 5 hours, depending on the size and condition.

How much does roof and gutter cleaning cost?

The cost to clean gutters is $160, plus $425 to clean the roof.

How do I know when to replace roof flashing or shingles vs. washing?

Missing or damaged shingles need replacing. When the flashings leak, it’s time to repair or replace them.