Karnak - 19 Flashing Cement, 1 gallon

Karnak 19 Flashing Cement is a high-performance, trowel-grade compound built for sealing joints, edges, and vulnerable roof features. Packaged in a convenient 1-gallon can, it’s ideal for small repairs and precision patching jobs. Its durable formulation stays flexible after curing, resisting cracking and moisture infiltration even on vertical surfaces exposed to harsh conditions.

Key Features

• Heavy trowel-ready consistency applies easily and resists slumping
• Forms a flexible, resilient, long-lasting seal on shingles, masonry, metal, and more
• Excellent adhesion and weather resistance, even under temperature extremes
• Available in Summer, Semi, and Winter grades for seasonal adaptability

Packaging: 1 gallon can (also comes in 3‑gallon buckets, 5‑gallon pails, and 55‑gallon drums)

• 1-gallon Can - 6 Cans/Case; 32 Cases/Pallet
• 3-gallon Bucket - 70 Buckets/Pallet
• 5-gallon Pail - 42 Pails/Pallet
• 55-gallon Drum - 4 Drums/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 (after curing): 15 °F to 180 °F

Weight per gallon: approximately 7.6–7.7 lb

Solids: about 76% by weight; 73% by volume

VOC content: maximum 250 g/L

Meets: ASTM D‑4586 Type I Class I and Federal Specification SS‑C‑153 Type I (asbestos-free)

* This item is hazmat *

• Clean the surface thoroughly, ensuring it is free of dust, oils, or debris. If temperatures are below 40 °F, ensure the surface is completely dry.
• Apply the cement with a trowel at an average thickness of 1/8 in, pressing it into cracks, seams, or joints for adhesion.
• For larger repair areas, embed reinforcing fabric such as saturated cotton, fiberglass mesh, or Resat‑Mat, then apply a second coat over the patch.
• Smooth the finish to ensure an even application with complete substrate contact.
• Allow the repair to cure fully before exposing it to moisture or foot traffic.
• Clean tools with mineral spirits and work in a well-ventilated area.

Q: What materials can this flashing cement be used on?
A: It adheres well to shingles, concrete, metal, asphalt, flashings, chimneys, brick, and other exterior surfaces.

Q: What are the recommended temperature ranges for use and service?
A: Apply between 40 °F and 120 °F (ensure the surface is dry when below 40 °F). Once cured, it performs from 15 °F to 180 °F.

Q: How much area does a 1-gallon can cover?
A: It covers approximately 100 sq ft at an application thickness of 1/8 in.

Q: Should I reinforce large or cracked areas?
A: Yes. Reinforce with fabric or mesh, then top-coat with another layer of 19 cement for durability.

Q: Does it meet industry standards for roofing cements?
A: Yes—it complies with ASTM D‑4586 Type I and Federal Specification SS‑C‑153 Type I.