Karnak - 19 Flashing Cement, 10.1 oz. Tube

Designed for focused roof repair, this compact cartridge of Karnak 19 Flashing Cement provides a precise, resilient seal around details like flashing edges, seams, and vent bases. Its robust yet trowel-friendly formula ensures a dependable barrier—flexible enough to accommodate movement and tough enough to uphold long-term performance even when temperatures fluctuate.

Key Features

• Trowel-ready consistency that applies cleanly and resists slippage on vertical surfaces
• Forms a tough, waterproof, and flexible seal when cured
• Adheres to various substrates including masonry, metal, shingles, and concrete
• Available in Summer, Semi, and Winter formulations for seasonal use

Container: 10.1 oz tube (cartridge); 48 Tubes/Case; 32 Case/Pallet

Application temperature: 40 °F to 120 °F (substrate must be dry below 40 °F)

Coverage: approximately 8 gallons per 100 sq ft at 1/8 in thickness

Service temperature (cured film): 15 °F to 180 °F

Weight per gallon (for physical property reference): ~8.93 lb

Solids: approximately 77% by weight; 70% by volume

VOC content: up to 250 g/L maximum

Meets ASTM D‑4586 Type I (Class I) and Federal Spec SS‑C‑153 Type I standards

• Clean and dry the surface, ensuring it is free of dust, oil, or loose materials.
• Load the tube into a standard caulking gun and cut the nozzle to the desired bead width.
• Apply a thin layer (~1/8 in) over cracks, seams, or flashing areas, pressing firmly for adhesion.
• For larger damage, embed reinforcing fabric such as saturated cotton or fiberglass mesh, then topcoat with another layer.
• Smooth as needed for a uniform finish and allow to cure completely before exposure.
• Clean tools with mineral spirits and operate in well-ventilated conditions.

Q: Why choose the tube format?
A: It allows precise application, especially useful in tight, elevated, or hard-to-reach areas.

Q: Can this cement be applied in cool or damp conditions?
A: It bonds well even to damp surfaces, though substrates should be as dry as practical for best results.

Q: What’s the coverage per tube?
A: One tube covers approximately 100 sq ft when applied at 1/8 in thickness (about 8 gallons per 100 sq ft).

Q: Do I need reinforcement for large repairs?
A: Yes. Embedding fabric or mesh before applying a second coat improves longevity and performance.

Q: Does it yield long-term flexibility?
A: Yes—it remains elastic and weather-resistant across its service temperature range of 15 °F to 180 °F.