Having a metal roof installed is a great decision for any homeowner! Metal roofs are a superior roofing product that last for decades; they withstand harsh weather events, are fire-resistant, and reflect heat. In order to reap all of these benefits fully, regular cleaning and maintenance is critical. Regularly cleaning your roof helps maintain the finish and prevents dirt and stains allowing you to maintain the value of your property. Cleaning your roof also extends the longevity of the roof and can help reduce costly repairs.
Most experts recommend that you clean a metal roof at least once a year to prevent dust and dirt build up to keep the roof in proper working condition. And with just a little bit of love, a metal roof can achieve more than you expect and last a long time!
At Roof Rescue, we have worked on many roofs that looked new after twenty years, and we have seen a couple that were in premature failure because cleaning was not properly performed. Regularly cleaning your metal roof is important to keep its appearances and to prevent damage from rust or corrosion. That’s why we pulled this reference guide together: to be a real, honest guide to you, and not just another guide that tells you to “spray with soap and water.” We aim to create a legitimate resource to educate you on how to protect your roof and your home!
Why Cleaning is More Important Than You Think
Cleaning a metal roof is not about vain appearances. It is about stopping a chain reaction that starts with dirt and leads to corrosion. Leaves and pine needles hold moisture against the panels resulting in accumulated debris and a build up of dirt and other elements that can become stuck on the roof’s surface. The moisture creates a damp microclimate with thriving algae, lichen, and moss. Those organisms secrete acids and break down the protective coating. When the coating breaks down and the bare metal is exposed, rust takes over. Not cleaning a metal roof can cause wear-and-tear to increase and make the roof fail sooner than expected. The entire surface of the roof should be cleaned to remove stains, rust stains, and avoid further damage.
What was once a 50-year roof, now looks more like a 20-year time liability. Not addressing the affected areas will only lead to greater stains and damage. A couple of hour ritual of cleaning each season is way better than spending too much time and money to replace panels decades sooner than anticipated.
The Benefits of a Clean Roof
To keep your roof clean and clear of grime and growth does more than stop rust. It will help extend the life of the roof’s protective coating that metal roofs come with a cleaner roof keeps the roof’s benefits of strength and bringing long-term value to homeownership. A clean roof has fewer hidden costs and gives your home much more curb appeal.
- Energy efficiency: A clean reflective surface absorbs less heat helping you save money on your cooler bills during the hot summer months.
- Warranty coverage: Many warranties require documented maintenance (such as a metal roof cleaning) in order to remain valid and warranty the protective coating.
- Curb appeal and resale value: A clean roof will WOW any buyer and an appraiser making your first impression overpowering. Cleaning your painted metal roof is key to maintaining its attractiveness and finish.
- Better health: Removing mold, mildew, and moss from your roof can reduce airborne spores that may exacerbate allergies. A clean metal roof helps mitigate this, which is less of an issue with metal roofing but still a consideration.
- Cost savings: A clean metal roof allows more reflection of sunlight which will help with cooling costs when it’s warm.
Safety First: Non-negotiable considerations
Working on a metal roof is different than working on asphalt shingles. Metal becomes unbelievably slippery, particularly if it is wet, and a fall from a rooftop is devastating. There are valued precautions to take when cleaning a metal roof as a huge part of safety is simply doing routine maintenance to protect yourself from injury. Treat this situation as a construction project and not something you can squeeze into one weekend.
- Never work by yourself. A spotter on the ground is an insured best practice.
- Wear appropriate footwear. Soft sole shoes with high-traction grips.
- Wear fall protection. Wearing a safety harness on any roof with a pitch is mandatory.
- Step smart. Walk on the flat portions of the panels and not the raised seams or ribs to avoid popping and denting and breaking the seals.
- Walk as little as possible. Clean from a ladder, aerial lift, or walk boards to balance weight.
- Wear eye protection from splashing and debris. Before climbing on the roof, perform an inspection from the ground with your eyes to check for any obvious hazards or debris.
Choosing Your Cleaning Products: What to get (and what NOT to get)
Your roofs finish is tough, but a wrong cleaner, or tool will ruin it in a minute. Cleaning products should be chosen to prevent severity of damage to the metal roof’s finish as well as the effectiveness of it. I recommend that you should always start with the weakest option first, and then work your way up if needed.
Best products:
- Plain old water: Usually enough to rinse dust and pollen off of your roof surface.
- Solution of gentle detergent: Mix ¼ cup of dish soap per clear gallon of water — simple, safe, effective.
- Car wash soap: or another gentle cleaning agent which is safe on metal roofs, and good at washing away organic dirt without damaging the finish.
- Eco-friendly cleaners: a 50/50 solution of water and white-vinegar will kill and remove algae and mildew. watered down oxygen bleach works well too.
- Speciality options: For lichen/ moss that doesn’t simply rinse off check out some products like Wet & Forget or Bio-Shield. These products kill the growth over time, and lets the rain wash them away.
- Soft bristle brush: with a soft bristle brush or sponge apply your cleaning solutions in a circular motion, this will lessen the amount of damage you can do to the paint.
- Manufacturer’s instructions and recommendation: Follow the manufacturers instructions and recommendation when choosing a solution and cleaning product to ensure that you do not void your roof warranty or cause any unnecessary damage.
Add Your Heading TextAvoid at all cost: Here
- Abrasives: Wire brushes, steel wool, and scouring pads scratch permanent finish and void warranties.
- Harsh cleaning agents: solvents, paint thinners, and undiluted bleach can permanently damage the protective coatings.
- Paint removers and chemical cleaners: may remove dirt, but will damage the roof surface and void warranties approved by the manufacturer.
- High-pressure power washer and power washers: If misused, these may damage the roofing surface and/or use pressure to strip finish paint, and/or force water under seams. Avoid using high pressure — if necessary, use it at a very low pressure ONLY.
The Cleaning Process, Step by Step
A thorough clean follows a simple rhythm — for greatest effectiveness:
- Prepare: Pick a calm day without direct sunlight and no wind, and overcast is best. Cover landscaping and any potential run-off areas with tarps to protect from cleaning product run-off.
- De-bris: Use a leaf blower or a soft brush to de-bris the surface of the roof material of sticks, leaves, grit, etc. before you introduce water.
- Pre-rinse: Using a garden hose, spray water only onto the roof surface starting from the ridge and working your way down the roof surface. The pre-rinse will cool down the roof panels and sincle small fine dust as well.
- Apply cleaner solution: Work in small sections from the top down, and use a spray applicator to apply solution. You want to evenly apply the total surface area of each roof panel to cover each affected area. Wait for the cleaning solution to dwell for at least 5–15 minutes (the longer the dwell time, more contaminants it will lift); Don’t allow to dry.
- Light scrub (if needed): If needed, use a long-handled soft-brush to scrub your metal surface. You will probably want to focus your energy on damaging stains and the affected areas. Allow the cleaning final solution to do the work!
- Final rinse: The roof should be rinsed from the top, down until the water runs completely clear, and no cleaning solution and/ or residues remain on the total surface of the roof.
- Check: With the roof cleaned, it is a good opportunity to look for loose fasteners, scratches, or early rust before they develop into costly repairs.
If you are dealing with rust stains, make sure you deal with each stain separately. Superficial rust stains can usually be cleaned up by gently scrubbing the surface with a soft brush and a suitable cleaning solution for metal. For more persistent rust stains, any metal surface can be safely cleaned with oxalic acid. Again, make sure you follow all safety precautions and instructions from the manufacturer.
If you still have stubborn stains, or if the stain coverage area is large, consider hiring a roof cleaning service if you want it done safely.
DIY or Pro?
Many homeowners clean their own roof, but not everyone should. It comes down to level of comfortableness, roof complexity, and expense.
DIY is Best when: You have a single story building with low and walkable pitch and only light buildup, and you have the proper fall protection equipment.
Pro is Best when: You have a steep roof, multi story roof, or your roof needs specialized cleaning. A professional cleaner makes sure that the metal is cleaned safely and the cleaning conforms with the manufacturer’s cleaning guidelines. Professionals will bring commercial grade soft-wash systems, bubble insuranice, and the experience of working safe and according to the manufacturers warranty requirements.
Most professional cleanings for a standard metal roof usually cost between $350 and $700 and this is a cost that most homeowners feel is worth the time, risk, and effort saved. For tough stains or cleaning your metal roof safely, hiring a professional roof cleaning company ensures they have the experience and equipment to do the job without damaging your roof.
An Actionable Maintenance Plan
For best results, you will want to start with a yearly rhythm, so use this seasonal checklist to anticipate trouble on your roof. Seasonal maintenance check-lists can help homeowners remember to care for their metal roofs.
- Spring: Wash away pollen, debris stored from the winter, and any other remnants left by winter.
- Summer: After heavy storms, conduct a damage inspection from the ground.
- Fall: The most important season. Remove leaves, pine needles, debris, and other leftovers, and clear gutters before winter.
- Winter: In snow climates, monitor for ice dams, which can put stress on panels and seams.
Simple preventive habits can make the actual cleaning an easier task. Trim branches that overhang the metal roof, allow gutters to flow freely, and consider adding zinc or copper strips to the shady parts of the roof to help protect your roof from moss and algae in a natural way. Conducting these simple maintenance tasks means your metal roofing system stays cleaned and free of debris and build up.
Metal Roof Cleaning FAQs
What is the best thing to clean a metal roof?
The safest and most effective thing to clean a metal roof is a mild detergent solution. Many manufacturers approve using the mild detergent method that reflects an affordable solution and provides a good way to combat the same dirt that builds up and causes deficiencies in your metals finish. You may need specialized cleaning solutions for stains, especially tougher stains or rust stains. For the stubborn rusty stains, oxalic acid can be used, but you may have to use it with care.
Is Wet & Forget effective on metal roofs?
Absolutely, and it works on lichen and algae too. When it rains, the old growth is gradually washed away after a few months.
Can I pressure wash a metal roof?
Only with a very low pressure and a wide angle or fan tip — and still it’s risky. Too much pressure can strip the paint off, and push water under seals or seams.
How do I make my metal roof look new?
Having it deep cleaned brings back reflectivity and color. If the metal roof has stains, still consider cleaning for aesthetics and longevity, including tough stains and rust stains. Using oxalic acid can help with tough rust stains. After your cleaning, check for scratches, rust, or sealant failures, and the roof will look years younger.
Can I clean a metal roof with Dawn?
Yes. Dish soaps such as Dawn are perfect for making soft wash solution because they are neutral pH.
Should I power wash my metal roof?
In most cases, no. The risk of damaging your roof exceeds the upside of pressure washing. Soft washing and mild solutions are better. If you add a tough stain or cannot get rid of rust stains, consider hiring a cleaning service for roof cleaning.
The Bottom Line from Roof Rescue
A metal roof is made to last a long time, but you must make an effort. Regular and careful roof cleaning does not just make it look good; it protects the coatings, prevents the roof from corroding, and ensures the roof provides the service for which it was designed to last.
At Roof Rescue, we will help take the guess work out of maintenance. Whether you would like a professional cleaning, a full inspection, or advice on how to complete the job yourself, the same key applies: do not wait! Call Roof Rescue today for your free roof evaluation and ensure your roof is performing like new!
Mark Franklin, owner of Roof Rescue in Idaho Falls, Idaho, has been a trusted name in roofing since 2014. Serving Idaho, Montana, Wyoming, and Utah, Roof Rescue specializes in commercial and residential roof replacement and installation. Recognized for community initiatives like the “Operation Roof Rescue” program, which provides free roofs to local heroes, Mark combines professionalism with a passion for giving back. With 16 years of industry experience, an A+ Better Business Bureau rating, and glowing customer reviews, Mark’s leadership embodies quality and community-focused service.
