Should I Clean or Replace My Roof?

Kristin Luna
Written by Kristin Luna
Updated December 14, 2021
Photo: karamysh / Adobe Stock

Here’s what to know if you’re thinking of sprucing up your roof

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Nothing ruins the vibe of your home’s exterior aesthetic quite like a dirty or moldy roof, particularly if your paint color and roofing are both on the lighter side. The good news is that roofing materials are designed to last for decades, so cleaning is often the most sensible option if your roof simply is tainted by dirt, mold or algae. If your roof has run its lifespan, however, it might be time for a new one.

But before you decide which route is best for your home, you need to know the pros and cons of roof cleaning and roof replacement.

Roof Cleaning vs. Roof Replacement

Replacing a roof is a big financial investment that requires a lot of work, whereas cleaning it can save you time and money. But how do you know when it’s time to replace it, or if your room simply needs a good cleaning?

When Should You Clean Your Roof?

worker cleaning roof with high pressure hose
Photo: Marina Lohrbach / Adobe Stock

Routine roof cleaning is important because it not only keeps it beautiful, it extends its life. Cleaning your roof includes removing all the dirt and debris that/s collected, as well as clearing out your snow guards, removing leaves and sticks from gutters, and also addressing any other areas that are prone to buildup.

Other signs to look for when it’s time to clean your roof include the presence of fungus, algae, or moss that may be building up out of your sightline. Moss can cause your shingles to peel away from the adhesive connecting it to the adjacent shingle and blow off in a storm or strong wind. As the moss causes the roof to degrade, you might experience more serious problems like wood rot and decay down the line.

The common black streaks that form on asphalt shingle roofs are not necessarily a sign of an old roof. Rather, this unsightly surface mold, which hasn’t started to collect moss or algae, can often be fixed with a soft washing. This typically is done with a garden hose and cleaning products that dissolve the spores. 

If the discoloration is severe, you’ll need to use a high-pressure water sprayer instead. This method requires a more direct and close contact between the sprayer and the roof. This also means the additional expense of a contractor with a bucket lift system if your peaks are steep. Less pitched roofs that can be walked on are more easily accessible and therefore should be more affordable. If you don’t feel like tackling the mold yourself, it may be time to hire a professional to pressure-wash your roof.   

When Should You Replace Your Roof?

In general, a roof should last between 20 and 25 years—and with regular cleaning, or in drier areas of the country, even longer—so if you’re at the end of that timespan, it might be worth replacing your roof instead of simply doing a thorough clean.

Before you commit to new roofing, it’s important to understand what a roof replacement entails. Typically, the contractor will start by removing every asphalt shingle, bit of tar paper and all metal pieces, including gutters and waterproofing metal. This is a heavy-volume job with a lot of material waste and requires either a dumpster rental or multiple truckfuls to haul it all off.

All of the old nails must either be pounded back into the roof or removed and cleaned up with magnetic pickups, often right in the heart of your landscaping. If the removal process unearths damage to the roof, the old wood will need to be cut out and replaced. 

Once the surface is prepared for new asphalt roofing material, layers of tar paper and weatherized rubber seals are rolled across the roof before gutters and metal weatherproofing are replaced. Next, the shingles are hauled up onto the roof and knitted into place among the peaks and valleys of your house with air-compressor-powered nail guns.  

Pros and Cons of Replacing Your Roof

worker installing ceramic tiles on roof
Photo: bilanol / Adobe Stock

Replacing a roof can be costly, but worth it when considering the important role a roof plays in your home’s wellbeing. 

Cost Benefits of Roof Replacement

Adding a new roof instantly increases your home’s value. If you’re selling or planning to refinance your home, and your roof is at the end of its lifespan, it might be worth the extra investment to replace it.

Like any construction job, the price to replace a roof depends on the materials you choose and the labor involved. A new roof can cost anywhere from $5,000 to $45,000, depending on square footage and what kind of home you own. Cost of labor will depend on where you live, but in general you can expect to pay $25,000 on average to replace your roof

An asphalt shingle roof is on the lower end—averaging around $10,000 for a 1,600-square-foot home—though it has a shorter lifespan at 15 years. With a 20-to-30-year lifespan, a wood shingle roof costs around $21,500 for a 1,600-square-foot house, while clay or asphalt shingles will give you the most longevity (up to 60 years) but also cost the most, at around $21,000 for a 1,600-square-foot home.

The Difficulty of Replacing Your Roof

If you have a technically challenging roofline, it’s going to cost more money to replace it. Roofing is a time-and labor-intensive job that requires a substantial skill set and strength and is on the more challenging end of the DIY spectrum. Unless you have prior experience with roofing, you might want to hire a local roofer to complete the job instead of tackling it yourself.

Time Required to Replace Your Roof

Roofers work in large teams and often complete an entire tear-off and replacement in one day. Complicated landscaping, difficult access points or technical gables can stretch the project into multiple days, but for a residential home, replacing a roof rarely takes more than a workweek to complete.

Summary of Roofing Options

  • If your roof is more than 20 years old, it might be time to replace it.

  • If your roof is coated in dirt, mold, or algae, you can likely get away with a deep cleaning.

  • Replacing your roof can increase the resale value of your home.

  • On average, it costs $25,000 to replace a roof.

  • Replacing a roof is a highly challenging DIY job, so it’s better to call a pro.

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