Mule-Hide Polyiso Flat Roof Insulation Board, 1 in. to 4 in. Thick, 4 ft x 8 ft Sheets, Polyisocyanurate Foam, Brown

Mule-Hide Poly Iso is a rigid polyisocyanurate insulation board for flat and low-slope roofs, offered here in nine variants from 1.0 in. to 4.0 in. thick in 4 ft x 8 ft or 4 ft x 4 ft footprints. Each variant sells as one sheet. Use it as the primary thermal layer beneath Mule-Hide or compatible roof membranes.

Key Features:

• Wide thickness range: The line spans 1.0, 1.5, 2.0, 3.0 and 4.0 in. boards so you can dial in the R-value per layer.
• Polyiso efficiency: Polyisocyanurate foam provides high thermal resistance per inch compared with many other rigid insulations.
• Large 4x8 sheets: Most variants come in 4 ft x 8 ft sheets to cover roof fields with fewer joints.
• Compact 4x4 option: A 2.0 in. 4 ft x 4 ft variant suits small roofs and easier handling.
• Brown board: All listed variants come in a brown color.
• Two product groupings: Variants are listed as Poly Iso 1 and Poly Iso 2 groupings across matching thicknesses.

Specifications Table:

Coverage & How Much You Need:

Each 4 ft x 8 ft sheet covers 32 sq. ft.; the 4 ft x 4 ft variant covers 16 sq. ft. Estimate total roof area, divide by sheet coverage, and add for waste, joints and perimeter layout.

Fit and Compatibility:

Intended as thermal insulation beneath low-slope roofing systems including Mule-Hide membranes. Attachment fasteners, adhesives, cover boards, membranes and sealants are sold separately.

Frequently Asked Questions (FAQ):

Q: What is included in a purchase?
A: One sheet of Mule-Hide polyiso insulation in the thickness and footprint you select.

Q: Which thickness should I use?
A: Choose per your roof's R-value target; thicker boards from 3 to 4 in. reduce the number of layers needed.

Q: What is the difference between Poly Iso 1 and Poly Iso 2?
A: The two groupings cover the listed thicknesses; the source listing does not state a functional difference, so confirm requirements for your assembly.

Q: How much area does one sheet cover?
A: A 4 ft x 8 ft sheet covers 32 sq. ft. and a 4 ft x 4 ft sheet covers 16 sq. ft.

Q: Does it need a cover board?
A: Follow your roofing system's specification; many assemblies place a separate cover board over the insulation, which is sold separately.

Expert Verdict — Reviewed by the SuperArbor Pro Desk

Polyiso is the workhorse insulation for commercial low-slope roofs because it delivers high R-value in thin layers. For tapered or multi-layer systems, keep joints staggered between layers and verify the specified compressive strength for your membrane type. On small repair areas, the 4 ft x 4 ft board reduces cutting and waste.

Sheets are large and light; secure them against wind on the roof and wear gloves and eye protection when cutting polyiso.

Order Mule-Hide polyiso flat roof insulation boards in the thickness and size your assembly calls for.