If your commercial roof in Mount Juliet is starting to show its age, someone has probably told you to “just coat it.” Sometimes that’s great advice. Sometimes it’s an expensive way to trap a problem under a shiny white layer.
A properly selected and applied roof coating can extend the service life of a sound flat or low-slope roof, reduce roof-surface temperatures, and delay replacement when the existing system is suitable for restoration. But it only works when the roof underneath is a good candidate and the job is done in the right order. This guide walks through what a professional should evaluate before recommending roof coating in Mount Juliet, TN, so you can ask better questions and avoid paying for a coating that fails early.
Why Are Commercial Property Owners Considering Roof Coatings?
Owners of warehouses, retail centers, offices, and light industrial buildings in Mount Juliet eventually face a decision about aging roofs: repair, restore, or replace.
Full replacement can involve tear-off, disposal, new insulation, and disruption to building operations. A coating system, when the roof qualifies, can be installed over suitable existing roofing with less removal and disruption. Tennessee’s hot summers also make reflective coatings appealing because they can reduce roof-surface temperatures.
If you’re still weighing the basic question, our article Is Roof Coating Worth It? covers the cost and value side in more detail. Here, we’ll focus on the technical side: what makes a coating job succeed or fail.
Which Commercial Roof Types Are Suitable for Coating?
The “substrate” is simply the existing roof surface the coating will bond to. Not every roof makes a good one. Here’s how common commercial roof types are evaluated.
- Metal roofs: R-panel, standing seam, and corrugated roofs may be suitable when the panels and supporting structure remain sound. Surface rust can be treated and primed as specified. Rusted-through panels need appropriate repair or replacement before coating. Loose or backed-out fasteners must also be addressed.
- Modified bitumen: These roofs may be suitable when the membrane remains sound. Granulated surfaces need preparation that removes loose material without damaging the roof.
- Built-up roofing (BUR): Smooth-surfaced BUR may be suitable. Gravel-surfaced BUR needs closer evaluation because its surfacing can complicate preparation or make it unsuitable for the proposed system.
- Single-ply membranes: TPO, EPDM, and PVC may be coated with systems approved for those substrates. Cleaning, any required primer, and adhesion testing should follow the coating manufacturer’s instructions.
- Spray polyurethane foam (SPF): A protective coating shields roofing foam from UV exposure. Maintaining and renewing that coating is part of normal SPF roof care, provided wet or damaged foam is addressed first.
When a roof is not a candidate: Widespread wet insulation, a deteriorated deck, loose or shrinking membranes, and extensive seam failure may make coating unsuitable. A coating cannot restore structural strength or replace damaged materials beneath the surface.
Why Must Moisture Testing Come Before Roof Coating?
Moisture evaluation is an important part of deciding whether a roof is suitable for coating. Water in the insulation does not disappear when a new coating is applied. It can reduce insulation performance and contribute to deterioration of the roof assembly.
Depending on the roof and initial findings, further investigation may involve:
- Infrared scanning: Performed under suitable conditions after the roof has absorbed solar heat. Temperature patterns can help identify suspected wet insulation, but findings may need confirmation through other methods.
- Moisture meters: Capacitance or impedance instruments can help investigate moisture patterns where suitable for the roof assembly.
- Core cuts: Small samples help confirm roof layers and moisture conditions at selected locations. Openings must be properly repaired afterward.
Wet areas should be removed and replaced with suitable insulation and roofing materials before coating. If investigation identifies extensive damage, coating may no longer be the most cost-effective option. The decision should consider moisture damage, the condition of the assembly, repair requirements, and the cost of restoration versus replacement.
The number and condition of existing roof layers should also be evaluated against applicable project and system requirements.
What Repairs Are Needed Before Coating?
A coating cannot replace repairs to damaged roofing components. Before application, the crew should address conditions such as:
- Open or failing seams and laps.
- Blisters, splits, and punctures in the membrane.
- Deteriorated flashing at walls, curbs, and edges.
- Damaged pitch pans, pipe boots, and other penetration details.
- Loose, missing, or corroded fasteners on metal roofs.
- Clogged drains, scuppers, and gutters.
Ponding water deserves special attention. Water remaining after rainfall may indicate blocked outlets, inadequate slope, or localized low spots. Some coatings tolerate ponding exposure better than others, but coating does not correct drainage. Improvements may involve crickets, tapered insulation, or changes to drainage outlets, depending on the roof design.
How Should a Roof Be Prepared for Coating?
Preparation is essential to adhesion. Good preparation typically includes:
- Cleaning: Remove dirt, chalking, algae, and loose material using a method and pressure suitable for the existing roof. Use approved cleaning products where required.
- Drying: Allow the roof to reach the surface conditions required by the coating manufacturer before applying primer or coating.
- Rust treatment: Remove loose corrosion and apply the specified treatment or primer to affected metal surfaces.
- Adhesion testing: Prepare, coat, cure, and evaluate test areas according to the manufacturer’s procedure where required.
- Priming: Apply the primer required for the substrate, coating system, and adhesion findings.
Seams, fasteners, and penetrations are then detailed according to the selected system. This may involve reinforcing fabric, compatible mastic, sealant, or other specified components.
How Is a Commercial Roof Coating Applied?
With repairs and preparation complete, coating is applied by an approved method, such as spray or roller. Some systems use a base coat and topcoat; others have different application requirements.
Choosing the right chemistry. Acrylic coatings are reflective and often cost-effective, but many require good drainage and are not intended for prolonged ponding. Many silicone products resist UV and ponding exposure, although compatibility with future recoats needs consideration. Some urethane products offer added resistance to traffic or impact. Product specifications determine suitability.
Hitting the right thickness. Coating systems have specified coverage rates and film thicknesses, measured in mils. Applying less than the required thickness can reduce performance and affect warranty eligibility. Wet-film checks and material-use records help verify application, with completed coverage evaluated using the appropriate method.
Working in the right weather. Coatings need suitable temperatures, surface conditions, and time to cure before rain or heavy dew. Sudden storms and changing temperatures can affect the application schedule in Mount Juliet.
Final inspection. The completed coating should be checked for thin areas, pinholes, missed details, and other defects using methods appropriate to the system.
Product Warranty vs. Expected Service Life: They Are Not the Same Thing
A warranty describes coverage under specific written terms. Expected service life describes how long the coating remains serviceable on your roof.
A material warranty generally addresses qualifying defects in the coating product. It may exclude installation errors and repair labor. The actual remedy depends on the written terms.
A system or workmanship warranty may come from the manufacturer or contractor. Coverage can depend on installer eligibility, specified thickness, approved preparation and repairs, inspections, and maintenance records.
Expected service life depends on coating type, application thickness, preparation, sun exposure, traffic, drainage, and upkeep.
Here’s why the difference matters:
- A 10-year warranty does not mean the coating stops working in year 11. A properly applied and maintained system may remain serviceable beyond its warranty period.
- A longer warranty does not guarantee trouble-free performance throughout the term. Inspections, maintenance, and timely repairs may be required.
- Some systems can be recoated to extend protection when the existing surface and underlying roof remain suitable.
- Longer warranty options may require greater thickness or additional components, depending on the manufacturer’s specifications.
When comparing quotes, ask for the coating system, specified dry-film thickness, written warranty terms, exclusions, and maintenance requirements. Confirm who issues each warranty and what remedies it provides.
Ongoing Care After the Coating Goes On
A coated roof still needs attention. Plan for inspections twice a year and after major storms, along with any maintenance required by the selected system. Keep drains and gutters clear, protect service routes, and address damage promptly.
As the coating wears, cleaning, repairs, and a compatible recoat may be possible. The roof’s condition and manufacturer requirements determine whether recoating is appropriate.
Working With a Contractor You Can Trust
A useful proposal should explain why the roof is suitable for coating, how moisture was evaluated, what repairs are needed, and which coating system is proposed. It should also specify application thickness and clarify warranty coverage.
For more information about roof coating services, see our First-Rate Roof Coating Services page.
Schedule a Roof Coating Assessment in Mount Juliet
If you manage a commercial building in Mount Juliet or nearby Wilson County, contact Glick Roofing Systems to discuss whether coating may fit your roof. An assessment should consider the existing materials, moisture condition, drainage, and repairs needed before restoration.
Call 615-265-0598 to discuss your roof coating evaluation.
Frequently Asked Questions
1. How long does a commercial roof coating last?
Service life varies with the coating product, application thickness, preparation, exposure, drainage, and maintenance. A warranty period is not the same as an expected lifespan. Some systems can be cleaned and recoated when the coating and underlying roof remain suitable.
2. Can you put a roof coating over a leaking roof?
A roof with localized leaks may qualify after the leak sources are repaired and wet or damaged materials are replaced. Applying coating over unresolved defects does not address damage beneath the surface.
3. Is roof coating cheaper than roof replacement?
Coating a suitable roof often costs less because it can reduce tear-off, disposal, and replacement materials. Extensive moisture damage or preparation work can narrow the difference. Compare the complete restoration scope with replacement.
4. Can a roof coating be applied to a roof with ponding water?
Some products tolerate ponding exposure, but the roof must meet the selected system’s requirements. Persistent ponding should be evaluated and drainage improvements considered before coating. The surface must also meet application conditions when the coating is installed.
5. Does a reflective roof coating lower energy bills?
Reflective coatings can reduce roof-surface temperatures and may lower summer cooling demand. Actual savings depend on insulation, HVAC performance, climate, and how the building is used.
6. Will coating my roof void my existing roof warranty?
It may affect coverage. Existing roofing warranties can restrict alterations or products applied over the membrane. Review the written terms and confirm compatibility and any required authorization with the warranty issuer before coating.