Johns Manville RetroPlus 1/2 in. x 4 ft. x 8 ft. Roof Board

This is a Johns Manville RetroPlus roof board in a 4 ft. x 8 ft. panel, 1/2 in. thick, for commercial low-slope roofing assemblies. One sell unit is a single panel. Use it as a roof board within JM roofing systems; attachment hardware is per the JM assembly specification.

Key Features:

• Large panel format: 4 ft. x 8 ft. panel covers more area per board for faster installation.
• Code listed: UL Classified, FM Approved, and Miami-Dade County Approved.
• ASTM standard: Meets ASTM C728, Type 3.
• Manageable weight: Approximately 17.7 lb gross weight per panel.
• JM system component: Part of the Johns Manville roofing insulation and cover boards lineup.

Specifications Table:

Coverage & How Much You Need:

Each 4 ft. x 8 ft. panel covers 32 sq ft of roof area. Divide total roof area by 32 and add a waste allowance for cuts.

Fit and Compatibility:

Intended for Johns Manville commercial roofing assemblies under JM membranes. Fasteners, plates or adhesives are sold separately per the JM system specification.

Frequently Asked Questions (FAQ):

Q: What comes in one order?
A: One 1/2 in. thick, 4 ft. x 8 ft. RetroPlus roof board panel.

Q: How much area does one panel cover?
A: 32 sq ft; divide the roof area by 32 to estimate panel count, plus waste for cuts.

Q: Which approvals does it carry?
A: UL Classified, FM Approved, Miami-Dade County Approved, and it meets ASTM C728, Type 3.

Q: How is it attached?
A: Per the specified JM roofing assembly, typically with mechanical fasteners and plates or approved adhesive, sold separately.

Q: How heavy is a panel?
A: The listed gross weight is approximately 17.7 lb per panel.

Expert Verdict Reviewed by the SuperArbor Pro Desk

The 4×8 RetroPlus format suits open-field reroofing where larger boards speed coverage, while the 4×4 variant is handier around congested roofs. Verify the board is accepted in your specified JM assembly and follow the printed fastening pattern. Keep boards dry and flat until the membrane goes down.

Use proper lifting technique and OSHA-compliant fall protection when handling and installing roof boards on commercial roofs.

Get the Johns Manville RetroPlus 1/2 in. 4 ft. x 8 ft. roof board for efficient retrofit roof coverage.

Product Documents:

• Installation Guide (PDF)
• Product Data Sheet (PDF)
• Safety Data Sheet (PDF)