Black Jack All-Weather Roof Cement delivers what Montana contractors need most during storm season — a fiber-reinforced asphalt cement that bonds to damp surfaces. At 12 square feet per gallon coverage at 1/8” thickness, this thick trowel grade formula handles emergency repairs when waiting for perfect weather isn’t an option.
Application Specs and Temperature Guidelines
The temperature window matters. Apply when surface temperature sits between 50°F and 120°F. If below 50°F, store the bucket at 70°F-80°F for 24 hours before use. That storage requirement isn’t optional — cold cement won’t spread properly and won’t bond right.
Application thickness runs 1/8” to 1/2” thick, extending 2-3 inches beyond the damaged area. Use a trowel or putty knife to apply generously. For larger repairs, embed a strip of universal patching fabric between two layers of cement.
| Specification | Value |
|---|---|
| Coverage | 12 sq. ft. per gallon at 1/8” thickness |
| Weight | 44-48 lbs per 5-gallon bucket |
| Consistency | Thick trowel grade |
| Application Temperature | 50°F to 120°F surface |
| Cure Time Before Coating | 30-60 days |
| VOC Content | < 250 g/L |
Compatibility Limitations and Real-World Use
NOT suitable for rubber membranes or EPDM roofing systems. This matters because contractors need to know what it won’t stick to before climbing onto a wet roof. Works on asphalt roofing surfaces, wood, and metal — basically everything except rubber roofing.
The product cannot be painted over. Plan accordingly if aesthetics matter on visible repairs. The fiber-reinforced asphalt base stays black and glossy permanently.
Common applications include sealing around vent pipes, skylights, chimneys, valleys, and flashings. Also handles below-grade waterproofing and damp-proofing, plus exterior wall and foundation joint crack repairs. The ability to work on wet surfaces makes it invaluable for emergency repairs during Montana’s unpredictable weather.
Gardner-Gibson backs it with a 3-year limited warranty against material defects. Coverage includes product replacement or prorated refund but excludes labor and consequential damages. Miami-Dade County approved, which matters for wind-driven rain resistance even in Montana.
Frequently Asked Questions
Can Black Jack All-Weather Roof Cement be applied in the rain? Yes, it can be applied to damp surfaces, making it suitable for emergency repairs during wet weather. Surface temperature must be between 50°F and 120°F for proper adhesion.
How much area does one gallon cover? Approximately 12 square feet per gallon at 1/8” thickness. Thicker applications for deeper cracks will reduce coverage proportionally.
What surfaces won’t it stick to? NOT suitable for rubber membranes or EPDM roofing systems. Compatible with asphalt roofing surfaces, wood, and metal.
How long before I can apply a reflective coating over it? Allow the repair to cure for 30-60 days before applying any reflective coating. The cement itself cannot be painted over.
Do I need to heat the bucket before use in cold weather? If below 50°F, store product at 70°F-80°F for 24 hours prior to use. Cold cement won’t spread or bond properly.
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