Gardner elastomeric roof coating is a flexible, liquid-applied product intended to protect and help maintain compatible roof surfaces. Homeowners and building managers may consider it to reduce water entry, reflect sunlight, or extend the service life of a roof that is still in sound condition. The right choice depends on the specific Gardner product, roof material, climate, and preparation. Understanding those factors—and following the product label—helps prevent common problems such as poor adhesion, trapped moisture, and premature peeling.
What Is Gardner Elastomeric Roof Coating?
Gardner elastomeric roof coating is a roof-applied liquid coating that cures into a flexible film. “Elastomeric” describes its ability to stretch and recover to some extent as the roof moves with temperature changes. Depending on the product, a coating may also be formulated to reflect sunlight, resist weather exposure, or help seal small surface imperfections.
Gardner offers multiple roof-care products, and formulas are not interchangeable. Some are intended for particular roof materials or conditions, such as metal, mobile-home roofs, or general maintenance. Product names, colors, compatible substrates, and application directions can change. The label and current technical data sheet for the exact product take priority over general advice.
A roof coating is not the same as a new roof membrane or a full structural repair. It is typically applied over an existing, compatible surface. It cannot reliably correct a failing roof, replace damaged decking, or make a wet roof assembly sound.
What Gardner Roof Coating Can—and Cannot—Do
When the roof is suitable and the coating is correctly applied, it can provide a protective surface layer and may help limit exposure to sun and weather. A white or light-colored product can reflect more sunlight than a dark roof surface. The actual cooling benefit depends on the product’s measured properties, local climate, roof construction, insulation, and building use.
Coating may also help protect a roof from normal weathering and can seal certain minor surface defects if the product is designed for that use. It is not a universal leak stopper. Active leaks, loose seams, open joints, rust holes, deteriorated flashing, and soft or damaged roofing usually require repair before coating—and some conditions require a roofing professional.
- It may help: protect a compatible, prepared roof and improve solar reflectance when the selected product is reflective.
- It does not automatically: waterproof every roof, repair structural damage, or stop leaks caused by failed details.
- It cannot overcome: poor surface preparation, incompatible materials, standing water beyond product limits, or application in unsuitable weather.
Common Roof Types and Compatibility
Compatibility is one of the most important decisions when choosing a Gardner elastomeric roof coating. A product designed for one substrate may not adhere to another. Metal, asphalt-based roofing, previously coated surfaces, and other roof materials can require different primers, repairs, or coating chemistry. Some surfaces may be specifically excluded.
Before buying, check the container or manufacturer’s product page for the exact approved surfaces. Look for requirements covering existing coatings, primers, roof slope, moisture, and any restrictions on use over shingles or membranes. If a surface is not listed, contact Gardner or a qualified roofer rather than assuming that a coating labeled “roof” will work.
| Roof surface or condition | What to check |
|---|---|
| Metal roofing | Confirm the coating is rated for the metal type and existing finish. Check for rust, loose fasteners, failed seams, and required rust treatment or primer. |
| Previously coated roof | Confirm compatibility with the old coating. Test adhesion in a small area if the manufacturer recommends it, and remove loose or peeling material. |
| Asphalt-based roofing | Check the product’s explicit approval. Some coatings are not suitable for every asphalt surface or roof assembly. |
| Wet, damaged, or ponding roof | Address moisture, structural concerns, drainage, and failed areas before coating. Verify any limits on ponding water in the product instructions. |
How to Evaluate a Roof Before Coating
A careful inspection helps determine whether a roof is a coating candidate. Check the roof and, where accessible, the underside or attic for water stains, soft decking, mold-like growth, or other signs of moisture. On the surface, look for open seams, cracked or missing components, rust, blisters, loose material, failed flashing, and areas where water collects.
Small defects may be repairable with products specifically approved for the roof system. Larger areas of deterioration, recurring leaks, or widespread trapped moisture call for professional assessment. Applying a coating over concealed moisture can trap water and contribute to blistering, poor adhesion, or continued damage.
Roof access also creates fall hazards. A roof may be slippery even when dry, and coatings can make it more so. If the roof is steep, fragile, high, or difficult to reach safely, inspection and application should be left to a trained professional using appropriate fall protection.
Surface Preparation Before Application
Preparation is essential to coating performance. Follow the specific Gardner instructions, since cleaning methods and repair requirements vary by formula and roof material. In general, the surface must be sound, clean, and dry enough for the product to adhere. Dust, oil, loose coating, algae, and other contaminants can interfere with bonding.
- Read the label and technical data sheet. Confirm the approved surface, application temperature, weather window, coverage, drying time, and any primer requirements.
- Repair roof defects. Fix loose fasteners, failed flashing, open joints, damaged panels, and other defects using compatible materials. Let repairs cure as directed.
- Clean the surface safely. Remove dirt and loose debris using a method permitted by the manufacturer. Avoid damaging the roof or directing water beneath roofing components.
- Allow the roof to dry. Do not coat a damp surface unless the product explicitly allows it. Consider dew, overnight humidity, and rain in the forecast.
- Protect nearby areas. Mask surfaces that should not be coated and plan for runoff, overspray, and safe movement across the roof.
Cleaning can create environmental and safety concerns. Keep wash water and coating materials out of storm drains, and follow local rules for disposal. Use the safety information on the label and safety data sheet, including any required gloves, eye protection, or ventilation.
Applying Gardner Elastomeric Roof Coating
Application directions differ by product. Some coatings are applied by brush, roller, or spray, while others specify particular tools or techniques. Apply only within the temperature and weather conditions stated on the label. A forecast that includes rain, freezing conditions, or heavy dew during the required curing period can compromise the finished film.
Stir the material as directed, and avoid thinning it unless the manufacturer expressly permits thinning. Apply at the specified rate and thickness. Spreading a coating too thin can leave gaps and reduce protection; applying it too heavily may cause slow curing, cracking, or other defects. If more than one coat is required, observe the recommended recoat interval and application direction.
Do not estimate coverage solely from the size of the container. Coverage can vary with the product, surface texture, porosity, and application method. The label’s stated coverage is a planning figure, not a guarantee for every roof. A rough calculation is:
Estimated gallons needed = roof area in square feet ÷ labeled coverage per gallon.
For example, if a product label lists 100 square feet per gallon for a coat and the roof measures 1,000 square feet, the simple estimate is 10 gallons for that coat. The actual amount may be higher on rough or absorbent surfaces, and multiple coats require multiplying by the number of coats. Use the coverage and coat directions for the exact Gardner product.
Weather, Drying, and Curing
Temperature, humidity, sun exposure, wind, and roof moisture all influence drying and curing. A coating that feels dry on the surface may not be ready for rain, foot traffic, or another coat. The product label should specify the relevant intervals and acceptable application conditions.
Plan around local weather rather than relying on a general “dry time.” A sudden shower can wash or damage uncured material. Strong wind can carry spray or debris, while intense heat may affect how the coating spreads. Cool or humid conditions may lengthen drying. If the forecast is uncertain, delaying application is often safer than risking a failed coating.
Reflectivity and Potential Energy Benefits
Reflective roof coatings can reduce the amount of solar energy absorbed at the roof surface. The U.S. Department of Energy explains that cool roofs reflect more sunlight and absorb less heat than conventional roofs, which may lower roof temperatures and reduce cooling demand in suitable buildings. Results vary: a coating does not replace insulation, air sealing, or an efficient HVAC system.
Buyers should check whether the particular Gardner product has published solar reflectance and thermal emittance data, rather than relying only on a color description or the term “reflective.” Product performance can also change as a roof weathers and collects dirt. The Cool Roof Rating Council provides product ratings for participating products; a rating should not be assumed unless the specific product appears in its directory.
Energy savings are not guaranteed. They depend on climate, building design, roof insulation, air conditioning use, and the condition and color of the roof before coating. Reflective surfaces can also have different effects in heating-dominated climates, so a coating decision should account for the building’s full energy needs.
Common Application Problems
Many coating failures trace back to a mismatch between the product and roof, or to inadequate preparation. Before application, verify compatibility and inspect the roof carefully. Afterward, do not assume that extra product can compensate for an unsuitable surface or ignored repair.
- Peeling or poor adhesion: Often associated with contamination, a damp surface, incompatible old coating, or missing primer where required.
- Blisters: Can result from trapped moisture, excessive film thickness, or application under unsuitable conditions.
- Early cracking: May indicate an incompatible product, movement or deterioration in the roof, or an application that does not follow instructions.
- Leaks after coating: May come from unrepaired flashing, seams, penetrations, or structural damage that the coating was not intended to fix.
- Uneven appearance: Can result from inconsistent application, different surface absorption, or inadequate mixing.
Do not apply another coat over a failure without first identifying its cause. A repair may require removing loose material, drying the roof, correcting the underlying defect, or consulting the manufacturer or a roofing contractor.
Cost, Coverage, and Product Selection
The total cost depends on the exact Gardner product, roof area, surface condition, number of coats, repairs, tools, and labor. Product prices and availability vary by retailer and location, so a current estimate should be based on local quotes and the manufacturer’s stated coverage. Include cleaning, compatible repair materials, primer if required, and safe access equipment—not just the coating.
When comparing products, review the following details rather than choosing by price alone:
- Approved roof materials and any excluded surfaces
- Required primer, preparation, and repair materials
- Coverage per gallon and specified number of coats
- Application temperature and rain-free curing period
- Resistance claims and any limits involving ponding water
- Warranty terms, including preparation and maintenance requirements
- Safety instructions and disposal guidance
Warranty language deserves particular attention. A product warranty may cover the coating itself under stated conditions without guaranteeing that the underlying roof will remain leak-free. Keep receipts, product details, and application records, and follow all requirements for inspection or maintenance.
When to Hire a Roofing Professional
Professional help is advisable when the roof has persistent leaks, widespread corrosion, soft or sagging areas, extensive blistering, or signs of moisture inside the building. A contractor can assess whether coating is appropriate or whether repair or replacement is more practical. This is particularly important when the roof is steep, fragile, or difficult to access.
For a professional quote, request a written scope that identifies the roof material, repairs, cleaning method, primer, coating product, number of coats, application rate, and warranty. Confirm that the contractor’s plan follows the current Gardner instructions and applicable local requirements. This makes estimates easier to compare and helps clarify what the work is expected to accomplish.
Reliable Sources for Product and Roof Guidance
For product-specific information, consult the current Gardner Coatings website, the label, and the technical data sheet for the exact coating. For general information about reflective roofs, see the U.S. Department of Energy’s cool roofs guidance. The Cool Roof Rating Council offers information about rated roofing products and performance. Product formulations and instructions can change, so current manufacturer documentation should be checked before purchase and application.