Karnak - 18 Perfectseal Flashing Cement 5 Gallon

A rugged, heavy-body flashing compound, Karnak 18 Perfectseal delivers a long-lasting, moisture-resistant seal on vulnerable roof areas. Its dense, trowel-ready formula combines premium asphalts, reinforcing fibers, and refined solvents, offering exceptional adhesion, vertical resistance, and flexibility for both flat and angled surfaces. Exceptionally versatile, it’s perfect for a wide array of quick repairs and complex overlays.

Key Features

• Thick, trowel-ready consistency that resists sagging on vertical surfaces
• Forms a tough, flexible, corrosion- and water-resistant seal when cured
• Excellent adhesion and weathering performance across a wide temperature range
• Available in Summer, Semi, and Winter grades to suit seasonal conditions

Packaging: 5‑gallon pail (also available in 3‑gallon pail and 55‑gallon drum)

• 5-Gallon Pail = 42 Pails/Pallet
• 3-gallon Bucket = 70/Pallet
• 55-Gallon Drum = 4 Drums/Pallet

Application temperature: 40 °F to 120 °F; substrates below 40 °F must be dry and free of moisture

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

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

Weight per gallon: approximately 7.6–7.7 lb

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

VOC content: up to 250 g/L maximum

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

• Ensure the surface is clean, dry, and free of oils, dust, or loose material. At temperatures below 40 °F, confirm the substrate is free of ice or moisture.
• Apply the cement by trowel to an average thickness of 1/8 inch, pressing it firmly into joints, seams, or cracks.
• For large repairs, embed reinforcing fabric such as saturated cotton, fiberglass membrane, or polyester overlay, then cover with another coat of cement.
• Smooth the surface, ensuring complete adhesion and even coverage.
• Allow the repair to cure fully before exposure to moisture or traffic.
• Clean tools with mineral spirits and ensure adequate ventilation during application.

Q: What surfaces can 18 Perfectseal Flashing Cement be used on?
A: It is ideal for repairs on shingles, concrete, metal, asphalt, flashings, chimneys, cornices, brick, and prefabricated roof structures.

Q: What temperature conditions are acceptable for application and service?
A: It should be applied between 40 °F and 120 °F (with dry substrates below 40 °F) and performs in the range of 15 °F to 180 °F once cured.

Q: How much coverage will one pail provide?
A: At 1/8 inch thickness, a 5‑gallon pail covers about 100 sq ft (approximately 8 gallons per 100 sq ft).

Q: Do I need reinforcement for big cracks or breaks?
A: Yes. For larger damages, embed reinforcing fabrics before applying another layer to ensure structural strength.

Q: Does this product meet recognized industry standards?
A: Yes—it meets ASTM D‑4586 Type I Class I and Federal Specification SS‑C‑153 Type I for flashing cements.