Your signage is often one of the first things people notice about your location. When it is clean, visible, and in good repair, it supports a polished and professional brand image. When dirt, staining, fading, or damage begins to build up, the sign may become harder to read and less representative of the business behind it.

A FedEx Office survey found that 76% of U.S. consumers had entered a store they had never visited before based on its signs. In the same survey, 68% said a store’s signage reflected the quality of its products or services, and 52% said they were less willing to enter a store with misspelled or poorly made signs. The survey did not focus specifically on dirty signs, but it does show how closely consumers can connect signage with the businesses it represents.

Regular cleaning and inspection can help you:

• Maintain sign visibility and brightness
• Reduce staining and premature wear
• Catch peeling graphics, failing lights, loose components, or water intrusion early
• Keep signage consistent with your brand standards
• Identify problems that require professional repair

Start with the material, not the mess: The right cleaning method depends on the sign’s material, finish, construction, and location. A technique that is safe for coated metal may damage vinyl or scratch a plastic sign face, so it is important to know what you are cleaning before reaching for a brush or bottle.

What Can Happen When Signs Are Not Cleaned?

1. Changes in appearance and material condition

Outdoor signs are exposed to dust, pollen, insects, bird droppings, vehicle exhaust, moisture, sunlight, and seasonal weather. Over time, these contaminants can stain surfaces, dull finishes, and reduce the apparent brightness of sign faces. 3M notes that accumulated dirt can produce noticeable changes in the color, appearance, and brightness of vinyl signs and awnings. It may also contribute to staining and premature wear.

Different materials age in different ways:

• Plastic sign faces can become scratched or hazy when cleaned with abrasive tools or incompatible chemicals. Some polycarbonate products are also vulnerable to UV-related yellowing unless they are manufactured with appropriate UV protection.
• Vinyl graphics can stain, lose gloss, or begin lifting at the edges when exposed to harsh chemicals, excessive pressure, or prolonged contamination.
• Painted or coated metal can lose its finish when abrasive or chemically incompatible cleaners are used. Damaged steel components may rust, while aluminum can oxidize, corrode, or develop water staining. Aluminum itself does not rust like steel. See the Aluminum Association’s guidance.
• Illuminated and digital signs may require cleaning around sign faces, louvers, vents, sensors, and other components. Their maintenance procedures should always follow the equipment manufacturer’s instructions.

In some rare cases, dirt can cause the sign to trap enough heat to cause warping of plastic components. Plastics can expand and bow as temperatures change, but those warping problems are more directly connected to material selection, installation, mounting, and the amount of room allowed for thermal expansion. Plaskolite’s technical guidance explains how temperature and installation conditions affect polycarbonate sheet movement.

2. Reduced visibility and a weaker brand presentation

Dust, stains, insects, and environmental buildup can obscure lettering and make a sign appear dimmer or less crisp. This is especially noticeable on illuminated sign faces, where the light must pass through a clean, intact surface.

Weather can make the problem more visible. Rain may turn settled dust into streaks, while snow and ice can temporarily cover lettering or damaged areas. Even when the sign remains readable, a neglected surface can feel out of step with an otherwise well-maintained property.

A dirty sign does not automatically prove that customers will avoid a business. Still, because consumers often associate sign quality with the business itself, keeping signage clean and functional is an important part of maintaining a consistent public image.

How to Clean Different Types of Signs

Before cleaning any sign, check its manufacturer, installer, warranty documentation, or product specifications when available. Begin with the least aggressive method and test any cleaner in a small, inconspicuous area.

Cleaning acrylic and polycarbonate sign faces

Acrylic and polycarbonate surfaces require gentle handling. Uncoated polycarbonate, in particular, can mar easily, and abrasive tools can permanently scratch the surface.

A safe starting process is:

1. Rinse the surface with clean, lukewarm water to remove loose grit.
2. Wash gently with diluted mild soap and a soft microfiber cloth or nonabrasive sponge.
3. Rinse thoroughly so no cleaner remains on the surface.
4. Dry with a clean, soft cloth to reduce water spotting.

Avoid dry wiping a dusty surface, since trapped particles can create scratches. Do not use abrasive pads, hard brushes, razors, scrapers, or squeegees unless the material manufacturer specifically approves them.

For bird droppings, tree sap, adhesive, or other stubborn contaminants, allow water and mild soap to soften the material first. Use only a spot cleaner that the manufacturer identifies as compatible with that particular acrylic or polycarbonate product.

Cleaning painted metal and aluminum signs

Metal signs are often protected by paint, powder coating, or another finish. Cleaning should preserve that coating rather than strip, dull, or scratch it.

For routine care:

1. Remove loose dirt with clean water at low pressure.
2. Use a mild, nonabrasive detergent that is compatible with the coating.
3. Apply it with a soft cloth, sponge, or approved soft-bristled brush.
4. Work from the top down to reduce streaking.
5. Rinse thoroughly and allow the surface to dry.

While cleaning, inspect seams, mounting points, fasteners, scratches, chips, and areas where moisture may collect. Steel components should be checked for rust. Aluminum may develop oxidation, corrosion, or water staining, but it should not be described as rusting. The Aluminum Association explains this distinction in its material-care guidance.

Do not automatically use a pressure washer. Water can be driven behind sign faces, into seams, or under applied graphics. Check with the sign manufacturer or maintenance provider before using pressurized equipment.

Cleaning vinyl graphics

Hand washing is generally the safest starting point for vinyl graphics.

For routine care:

1. Rinse away loose dirt, washing from the top down with clean water and mild detergent.
2. Rise thoroughly.
3. Allow the sign to air-dry or dry it with a microfiber cloth to prevent water spots.

Clean vinyl when the surface is cool and out of direct sunlight when possible. Pay particular attention to seams and edges, but do not scrub or pick at an area that is already lifting.

Avoid acetone, toluene, paint thinner, lacquer thinner, and other aggressive solvents. Isopropyl alcohol is permitted for spot cleaning on some films, but it is not universally compatible. Always check the film manufacturer’s instructions and test the cleaner before using it across the entire graphic.

Pressure washing should be a secondary option rather than the default. Many large vinyl manufacturers warn that excessive pressure can force water beneath a graphic and cause lifting, curling, abrasion, or other damage. Their technical limits also differ by product and application, which is why the graphic manufacturer’s instructions should take priority over a universal pressure or distance rule.

Cleaning illuminated and digital signs

Illuminated signs and digital displays introduce electrical components that are not present in ordinary non-illuminated signs.

Before cleaning:

• Turn off power according to the manufacturer’s instructions.
• Do not spray water into cabinets, seams, vents, wiring areas, or electrical enclosures.
• Use only cleaners and tools approved for the display face.
• Allow the sign to dry completely before restoring power.
• Leave wiring, power supplies, LED modules, and internal electrical work to a qualified service provider.

 

Creating a Practical Cleaning Schedule

There is no single cleaning schedule that works for every sign. Material, climate, orientation, traffic, pollution, landscaping, insects, and accessibility all affect how quickly a sign becomes dirty.

For vinyl signs and awnings, 3M recommends cleaning at least once a year. Signs in areas with heavy atmospheric pollution, pollen, or insects may need cleaning four times a year or more.

A practical schedule may look like this:

Sign condition or environment	Suggested approach
Normal outdoor conditions	Inspect routinely and clean when buildup becomes visible. For certain vinyl signs and awnings, annual cleaning is a manufacturer-supported baseline.
Heavy traffic, pollution, pollen, insects, salt, or industrial exposure	Inspect and clean more frequently. Quarterly cleaning may be appropriate for some vinyl signs and awnings.
After severe wind, hail, ice, or storms	Inspect for loose faces, cracks, water intrusion, leaning components, and lighting problems.
Indoor signs	Dust and spot-clean as needed, based on fingerprints, traffic, and visibility.
Digital or illuminated signs	Follow the equipment manufacturer’s inspection and cleaning schedule.
Unknown material or coating	Ask the installer, manufacturer, or maintenance provider before cleaning.

Rather than relying only on the calendar, look at the actual condition of the sign. A sheltered sign may need very little attention, while a sign near a busy road or industrial area may need much more frequent care.

Build a Simple Sign Maintenance Checklist

A short checklist makes it easier to identify small issues before they become larger service requests. We recommend that your locations’ general managers add sign inspections to their regular checklist.

During each inspection, look for:

• Dirt, streaks, stains, bird droppings, insects, or plant growth
• Fading, discoloration, haze, cracking, or surface scratches
• Peeling or lifting vinyl
• Loose fasteners, trim, letters, faces, or mounting hardware
• Leaning, movement, dents, or impact damage
• Dark, flickering, or unevenly illuminated areas
• Water inside a cabinet or signs of failed seals
• Blocked vents, dirty filters, or debris around digital equipment
• Rust on steel or corrosion and staining on other metals

Take dated photos and record any cleaner or method used. These records can help identify recurring problems, communicate with a maintenance provider, and document the care performed on the sign.

Choosing Cleaning Products and Tools

The safest cleaning kit is usually a simple one:

• Clean water
• A mild, nonabrasive detergent
• Clean microfiber cloths
• A nonabrasive sponge
• A soft-bristled brush, but only where the material manufacturer allows it
• A garden hose or other low-pressure water source

There is no universal detergent ratio that is appropriate for every sign. Follow the cleaner label and the sign material manufacturer’s instructions.

Avoid making bleach, ammonia, acetone, strong solvents, abrasive powders, or aggressive degreasers your default choice. A chemical that works on one vinyl film or coated metal finish may damage another. Start with the mildest approved option, test it in a hidden area, and rinse thoroughly.

Isopropyl alcohol deserves particular caution. Some manufacturers permit diluted alcohol for spot cleaning specific graphics or polycarbonate products. Others warn that alcohol or similar solvents can damage the finish. It should never be presented as a general-purpose cleaner for all signs. Review the applicable guidance from Plaskolite or Avery Dennison before using it.

Keep cloths, brushes, buckets, and sponges clean. A soft cloth can still scratch a surface when it carries sand or grit.

When to Hire a Professional Sign Maintenance Provider

Routine ground-level cleaning may be manageable for some businesses. Most other situations should be handled by trained professionals.

1. Hard-to-reach signs

Signs that require an aerial lift, bucket truck, scaffolding, roof access, or work near power lines involve significant fall and electrical hazards. Your sign vendor should be able to support cleaning and maintenance procedures for your sign.

2. Electrical problems

Dark letters, flickering illumination, exposed wiring, failed power supplies, or water inside an electrical cabinet require more than surface cleaning. Turn the sign off when it is safe to do so and contact your trusted sign partner.

3. Structural damage

A leaning sign, cracked pole, damaged cabinet, loose face, collision damage, or unstable mounting can create a public-safety concern and a liability concern for the business. Call local authorities, if necessary, and your trusted sign vendor for help in repairing the structure of the sign.

4. Specialized signage

Pylon signs, monument signs, channel letters, neon, digital displays, and complex illuminated systems often require specialized parts, access equipment, diagnostics, and installation knowledge.

5. Vandalism or major surface damage

Graffiti, broken faces, missing letters, deep scratches, or extensive coating damage may require professional cleaning, repainting, refacing, or replacement. The wrong chemical or scraping method can turn a repairable problem into permanent surface damage.

Why Choose North American Signs?

North American Signs has supported commercial signage programs since 1934. Our sign maintenance services include preventive care, repair, cleaning, decommissioning, multi-location coordination, and emergency response.

For businesses managing signage across multiple locations, we can help organize service requests, document recurring issues, coordinate qualified providers, and create a more consistent maintenance process.

NAS also offers 24/7 emergency response for urgent issues such as storm damage, collisions, structural damage, and electrical failures.

Professional maintenance can be especially valuable when a sign is difficult to access, involves electrical or structural components, or is part of a larger multi-site brand program.

Key Points for Extending Sign Life

Good sign care begins with a few practical habits:

• Inspect signage regularly and after severe weather.
• Clean according to the sign’s actual material and finish.
• Begin with water and the mildest compatible cleaner.
• Avoid abrasive tools and unsupported home-cleaning remedies.
• Follow manufacturer instructions for vinyl, plastic, coated metal, and digital displays.
• Document peeling, lighting failures, water intrusion, corrosion, and structural movement.
• Bring in a professional when height, electricity, structural damage, or specialized equipment is involved.

Regular care cannot stop every form of weathering or material aging. It can, however, help preserve the sign’s appearance, reduce preventable damage, and make it easier to address problems before they grow.

FAQs

How do I create the right cleaning schedule for my sign?

Start with the sign’s material, location, and exposure. A sheltered indoor sign may only need occasional dusting, while an outdoor vinyl sign near traffic, pollen, insects, salt, or industrial pollution may need much more frequent care.

For certain vinyl signs and awnings, 3M recommends cleaning at least once a year, with cleaning four times a year or more in heavily polluted or high-pollen environments. Other materials may have different requirements, so check the manufacturer’s documentation or speak with the installer.

How can I tell whether my sign needs professional maintenance rather than cleaning?

Cleaning is appropriate for ordinary surface dirt when the sign is stable, safely accessible, and free from electrical problems. Contact a professional when you notice:

• Cracks or broken sign faces
• Loose letters, trim, cabinets, or mounting hardware
• Leaning or structural movement
• Flickering or failed lighting
• Exposed wiring or water inside an electrical enclosure
• Peeling graphics that may require repair
• Significant corrosion, vandalism, or impact damage
• A sign that requires ladders, lifts, roof access, or work near power lines

What can happen if I use the wrong cleaning product?

An incompatible cleaner can dull a finish, discolor paint, haze plastic, scratch a sign face, weaken a protective coating, damage printed ink, or cause vinyl edges to lift.

Use a mild, nonabrasive cleaner that the material manufacturer identifies as compatible. Test it in an inconspicuous area, use clean tools, and rinse the surface thoroughly. When the material is unknown, pause before cleaning and ask the sign manufacturer or maintenance provider for guidance.