4 Types of Waterproof Roof Coatings: Costs, Benefits & Uses
A commercial roof doesn't always need to be completely replaced when it begins showing signs of age. If the existing roofing system is still structurally sound, a waterproof roof coating may provide another option for protecting the roof, addressing vulnerable areas, and extending its useful service life.
Roof coatings are fluid-applied materials that cure into a protective layer over an existing roofing surface. According to the Roof Coatings Manufacturers Association (RCMA), coatings can be used on roofing systems including metal, modified bitumen, built-up roofing, single-ply membranes, and spray polyurethane foam. They can provide additional protection against UV exposure, weather, and moisture while helping extend the useful life of an existing roof.
But not every roof coating performs the same way.
Four of the most common types are silicone, acrylic, polyurethane, and asphalt-based roof coatings. Understanding the differences can help commercial property owners determine which option may make sense for their building.
Here's what you should know about waterproof roof coating types, costs, benefits, and uses.
What Is a Waterproof Roof Coating?
A roof coating is a fluid-applied material installed over an existing roofing surface. Once cured, it creates a seamless protective layer across the roof.
Unlike conventional paint, roof coatings are formulated specifically for roofing applications and are applied at substantially greater thicknesses. The Roof Coatings Manufacturers Association explains that coatings use resins that allow the cured material to remain elastic while providing additional weather protection and helping bridge small cracks and membrane seams.
Depending on the product and roofing system, coatings may help:
Extend the useful life of an existing roof
Improve resistance to moisture
Protect roofing materials from UV exposure
Reduce roof surface temperatures
Seal small cracks and vulnerable areas
Reduce the need for an immediate tear-off
Improve overall roof performance
However, a coating isn't a solution for every damaged roof.
Before applying one, the existing roofing system should be inspected to determine whether it is an appropriate candidate for restoration.
1. Silicone Roof Coating
Silicone roof coating is one of the most popular choices for commercial roofs where moisture and ponding water are concerns.
Once applied, silicone forms a flexible, seamless membrane over the existing roofing surface.
According to GAF's commercial roof coating guidance, silicone coatings offer strong resistance to ponding water and UV exposure and can be used with several existing roofing substrates.
Benefits of Silicone Roof Coatings
Silicone coatings offer several potential advantages:
Strong water resistance
Excellent UV resistance
Flexibility
Seamless application
Good performance around penetrations
Compatibility with several commercial roofing systems
Reflective options
Because of their moisture resistance, silicone systems can be particularly useful on low-slope commercial roofs where temporary ponding water may occur.
Where Is Silicone Roof Coating Used?
Depending on the specific product and preparation requirements, silicone coatings may be used over:
Metal roofing
Built-up roofing
Modified bitumen
Aged single-ply membranes
Spray polyurethane foam
Previously coated roofs
The roof must still be properly evaluated and prepared before coating.
Potential Drawbacks
Silicone can attract dirt over time, which may affect the appearance and reflectivity of the roof. Silicone surfaces can also become slippery when wet.
Future repairs or recoating may require compatible products and appropriate surface preparation.
For those reasons, product selection and professional installation are important.
2. Acrylic Roof Coating
Acrylic roof coatings are another widely used option for commercial roof restoration.
These water-based elastomeric coatings are known for their flexibility, reflectivity, and resistance to UV exposure.
GAF describes acrylic coatings as an option for protecting structurally sound roofs against normal weathering, aging, and UV exposure.
Benefits of Acrylic Roof Coatings
Potential benefits include:
High reflectivity
UV resistance
Flexibility
Water-based formulation
Relatively easy application
Cost-effective restoration
Compatibility with several roofing substrates
Reflective acrylic coatings can be particularly attractive for commercial property owners interested in reducing roof surface temperatures.
The U.S. Department of Energy's cool-roof guidance explains that reflective roofing surfaces can stay cooler by reflecting more sunlight than conventional roofing materials.
Where Are Acrylic Roof Coatings Used?
Acrylic coatings may be appropriate for:
Metal roofs
Modified bitumen
Built-up roofing
Spray polyurethane foam
Certain single-ply roofing systems
Acrylic is often well suited for roofs with positive drainage where prolonged ponding water isn't a major concern.
Potential Drawbacks
Acrylic coatings cure through water evaporation, so weather conditions during installation matter.
They generally aren't the first choice for roofs with persistent standing water. Installation also requires appropriate temperatures and enough dry weather for the coating to cure properly.
For Minnesota properties, timing can therefore play an important role when planning an acrylic roof coating project.
3. Polyurethane Roof Coating
Polyurethane roof coatings, sometimes called urethane coatings, are known for durability and resistance to physical wear.
This can make polyurethane particularly useful in commercial environments where roofs experience regular foot traffic or mechanical activity.
According to GAF's commercial roof restoration guidance, polyurethane coatings provide strong durability, flexibility, and impact resistance.
Benefits of Polyurethane Roof Coatings
Advantages may include:
Strong impact resistance
Good durability
Resistance to mechanical wear
Flexibility
Strong adhesion
Performance in high-traffic areas
These characteristics can make polyurethane useful around rooftop HVAC equipment, service areas, walkways, and other locations where maintenance crews regularly access the roof.
Where Are Polyurethane Roof Coatings Used?
Depending on the system, polyurethane coatings may be used on:
Commercial flat roofs
Modified bitumen
Built-up roofing
Metal roofs
Spray polyurethane foam
Other compatible roofing substrates
Polyurethane is often selected when physical durability is an important consideration.
Potential Drawbacks
Polyurethane coatings may cost more than some acrylic systems and can be more difficult to install.
As with any commercial roof coating, compatibility with the existing roof needs to be verified before installation.
4. Asphalt-Based Roof Coatings
Asphalt roof coatings have been used in commercial roofing for many years.
The RCMA defines asphalt roof coatings as products containing an asphalt base along with solvents and mineral or other additives. Asphaltic emulsion coatings use an asphalt emulsion binder.
These products can be particularly useful when restoring compatible asphalt-based roofing systems.
Benefits of Asphalt Roof Coatings
Depending on the product, benefits may include:
Additional moisture protection
Compatibility with asphalt-based roofs
Cost-effective maintenance
Protection of aging roofing surfaces
Ability to address certain small cracks and weathered areas
Some asphalt coatings also incorporate aluminum pigments to increase reflectivity.
Where Are Asphalt Roof Coatings Used?
Common applications may include:
Built-up roofing
Modified bitumen
Other compatible asphalt-based roofing systems
Not every coating is appropriate for every substrate, so compatibility should always be confirmed before application.
Silicone vs. Acrylic vs. Polyurethane vs. Asphalt Roof Coatings
Which waterproof roof coating is best?
There isn't one coating that's ideal for every commercial roof.
Silicone may be particularly useful where ponding water and UV exposure are major concerns.
Acrylic can provide a cost-effective, reflective option for roofs with good drainage.
Polyurethane offers additional durability where foot traffic and impact resistance matter.
Asphalt-based coatings may provide an economical restoration option for compatible asphalt roofing systems.
The correct choice depends on the existing roof, building use, drainage, climate, budget, and long-term plans for the property.
How Much Does Waterproof Roof Coating Cost?
The cost of a commercial roof coating varies significantly from project to project, which is why a professional inspection is usually needed before developing an accurate estimate.
Factors affecting roof coating cost include:
Roof square footage
Existing roofing material
Condition of the roof
Coating type
Number of coats
Required coating thickness
Cleaning and preparation
Primer requirements
Seam repairs
Flashing repairs
Roof penetrations
Wet insulation removal
Accessibility
Labor
Warranty requirements
A relatively clean, structurally sound roof may require substantially less preparation than a roof with failing seams, wet insulation, damaged flashing, or extensive repairs.
Instead of evaluating a coating solely by its price per square foot, commercial property owners should consider the total roof restoration system and expected lifecycle value.
Can a Roof Coating Stop Leaks?
A waterproof roof coating can provide additional protection against moisture, but it shouldn't simply be applied over an unidentified leak.
Before coating, the source of existing leaks needs to be investigated.
Wet insulation and damaged roofing materials may need to be removed and replaced. Seams, flashing, penetrations, fasteners, and other problem areas may also require repairs.
For example, GAF's silicone restoration process calls for evaluating the roof, identifying wet areas, repairing the substrate, treating seams and penetrations, and then applying the coating system.
A coating works best as part of a properly designed roof restoration system, not as a shortcut for covering existing problems.
Roof Coating vs. Roof Replacement
One of the biggest reasons building owners consider coatings is the possibility of extending the service life of an existing roof without immediately completing a full replacement.
If a roof is structurally sound and the problems can be properly addressed, restoration may provide a practical alternative.
However, roof coating may not make sense if there is:
Extensive saturated insulation
Significant structural damage
Severe membrane deterioration
Widespread corrosion
Major drainage problems
Large areas of failed roofing
In these situations, roof replacement may provide better long-term value.
The only way to know is to evaluate the existing roofing system.
How Long Do Commercial Roof Coatings Last?
The lifespan of a roof coating depends on the product, application thickness, existing roof condition, climate, installation quality, maintenance, and warranty system.
Some manufacturer coating systems offer warranty or guarantee terms of 10, 15, or even 20 years, depending on the specific system and contractor qualifications.
Certain coating systems can also be recoated later, potentially extending the service life of a structurally sound roof even further.
Regular inspections and preventative maintenance remain important after installation.
Are Waterproof Roof Coatings Worth It?
For the right roof, they can be.
Commercial roof coatings can offer property owners several potential advantages:
Extended roof service life
Additional waterproofing protection
Reduced UV exposure
Reflective and energy-efficient options
Less disruption than some replacement projects
Reduced roofing waste
Potentially lower upfront costs than complete replacement
But the condition of the existing roof determines whether coating is a good investment.
That's why the first step shouldn't be choosing between silicone and acrylic. It should be having the roof inspected.
Commercial Roof Coatings in Mankato & Southern Minnesota
Minnesota's snow, ice, rain, hail, UV exposure, and seasonal temperature swings can put commercial roofing systems through demanding conditions.
If your commercial roof is beginning to show signs of age, you may have more than one option.
Elevate Roofing Solutions can inspect your existing commercial roofing system and help determine whether maintenance, repair, roof coating, restoration, or complete roof replacement makes the most sense for your property.
Whether you manage a warehouse, manufacturing facility, retail property, office, agricultural building, or another commercial facility in Mankato or Southern Minnesota, understanding your roof's current condition can help you plan ahead instead of waiting for a major leak.
Is a Waterproof Roof Coating Right for Your Building?
Silicone, acrylic, polyurethane, and asphalt-based coatings each provide different benefits. The best option depends on your existing roofing material, drainage, building use, roof condition, and budget.
A roof coating can be an effective way to protect and extend the life of a structurally sound commercial roof—but it needs to be the right product installed over the right roof.
Contact Elevate Roofing Solutions to schedule a commercial roof inspection and learn whether a waterproof roof coating, repair, restoration, or roof replacement is the right solution for your building.