The JM PermaPly 28 Base Sheet is a bur & mb systems for jobs that require Johns Manville model/MPN 90001258 in the RL sell unit. JM PermaPly 28 Lightweight Base Sheet Roofing Membrane, 106 ft L x 36 in W, Fiberglass/Asphalt

Key Specs

• Brand: Johns Manville
• Model / MPN: 90001258
• SKU: JMPPFBS
• Sell unit: RL
• Product type: BUR & MB Systems
• Size / color: 36" x 106'
• Category: Commercial Roofing | Commercial Roofing/Membranes | Commercial Roofing/Membranes/BUR & MB Systems
• Coverage / unit: 3 squares (300 sq ft) per roll

Key Features

• PermaPly 28 is designed for use as the first or base sheet in built-up roofing or modified bitumen roof assemblies
• Exceptionally pliable, easy to handle and lays flat
• Makes it suitable as an intermediate or ply felt in cold applied built-up and modified bitumen roof assemblies

Coverage & How Much You Need

This item is listed as 3 squares (300 sq ft) per roll. Use the project takeoff, manufacturer installation instructions, and expected waste/overlap to confirm the order quantity.

Compatibility / Fitment

Use this item only when the brand, model/MPN, size/color, sell unit, and system type match the project specification. Do not substitute it for a different bur & mb systems, pack size, color, membrane/system family, or installation condition without checking the manufacturer instructions.

FAQs

What exactly am I ordering?

JM PermaPly 28 Base Sheet, sold as RL, with SKU JMPPFBS and manufacturer model/MPN 90001258.

What model or part number should I match?

Match model/MPN 90001258 and confirm the brand is Johns Manville. If the job spec lists a different model, size, color, or system family, hold for review.

What unit is the price based on?

This listing is built around the RL sell unit. Confirm the unit before comparing price, quantity, or coverage.

How do I estimate quantity?

Use 3 squares (300 sq ft) per roll, then add waste or overlap per the manufacturer instructions and the project design.

What should be checked before purchase?

Confirm the model/MPN, sell unit, size/color, jobsite condition, compatible system components, and any manufacturer installation limits before approving the order.

Verify the manufacturer instructions, local code, and project specification before installation or substitution.

Product Expert Notes

Choose this item when Johns Manville model/MPN 90001258, SKU JMPPFBS, and the RL sell unit match the project requirement. It is best treated as an exact-match material selection, not a generic substitute.