Johns Manville 1-Part PermaFlash Liquid Flashing, Brown, 1 gal. or 5 gal.

JM 1-Part PermaFlash is a one-component, elastomeric, liquid-applied flashing made of asphalt/polyurethane resin, formulated for use with Johns Manville modified bitumen membrane products. It cures to a durable elastomeric film with no mixing required. Available in brown in 1 gal. and 5 gal. sizes.

Key Features:

• No mixing required: Single-component solution applies straight from the container with no mixing.
• Conforms easily: Easily conforms to various geometries and irregular shapes.
• Strong adhesion: Cures to a durable elastomeric film and forms exceptional bonds between modified bitumen and a variety of penetrating materials.
• UV stable: UV stable, high solids (80%) and low odor.
• Two pail sizes: Available in 1 gal. and 5 gal. units.

Specifications Table:

Coverage & How Much You Need:

Coverage per gallon is not stated; coverage depends on detail size and applied film thickness. Estimate by total linear feet of flashing details and choose 1 gal. pails for spot work or 5 gal. pails for larger jobs.

Fit and Compatibility:

Formulated for use with Johns Manville modified bitumen membrane products and bonds to a variety of penetrating materials. For two-part PMMA details on BUR and SBS systems, use JM PMMA Flashing Resin instead.

Frequently Asked Questions (FAQ):

Q: What is included?
A: One pail of brown 1-Part PermaFlash liquid flashing, in either 1 gal. or 5 gal.

Q: Does it need mixing or a catalyst?
A: No, it is a single-component product with no mixing required.

Q: Where is it used?
A: It is a liquid-applied flashing formulated for use with JM modified bitumen membrane products, conforming to irregular shapes and penetrations.

Q: Is it UV stable?
A: Yes, it is UV stable with 80% high solids and low odor.

Q: What size should I buy?
A: Choose 1 gal. for small details and repairs, and 5 gal. for larger flashing runs.

Expert Verdict Reviewed by the SuperArbor Pro Desk

One-part PermaFlash saves time on small penetrations and irregular details because there is no mixing or catalyst to manage; it is ideal with JM modified bitumen systems. Detail work in coats and respect cure time before exposure to traffic or covering. For BUR and SBS two-part PMMA details, use the PMMA Flashing Resin system instead.

Liquid flashing materials are adhesive and solvent-bearing; wear gloves and eye protection, ensure ventilation, and follow the manufacturer’s safety instructions.

Order JM 1-Part PermaFlash liquid flashing in 1 or 5 gallon pails for fast modified-bitumen flashing details.