EMERALD COAST ROOFSCAPES · GULF COAST
Commercial Roof Insulation & Tapered Systems
Address the layers beneath the membrane. Compare insulation, tapered drainage and cover boards as part of a commercial roof’s repair, recover or replacement scope.
ROOF SYSTEMS · GULF COAST
GenFlex Polyiso: thermal insulation, drainage and cover boards
These layers have different jobs. Select each layer for the deck, membrane and performance required by the building.
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| Product | Role in the roof | Published configuration |
|---|---|---|
| Flat Polyiso / GL ISO | Thermal insulation with a polyisocyanurate foam core and reinforced facers. | 4 × 4 or 4 × 8 ft boards; supplied brochure lists 1½–4 in thickness. |
| Tapered Polyiso | Creates a sloping surface to direct water toward outlets. | 4 × 4 ft boards; standard slopes of 1/16, 1/8, 1/4 or 1/2 in per foot. |
| Coated Glass Facer / CG ISO | Polyiso with coated inorganic glass facers. | Flat and selected tapered configurations. |
| HD ISO | High-density cover board above the insulation. | ½-in board; brochure lists R-2.5 and 11 lb for a 4 × 8 ft board. |
| Composite Polyiso / HD Comp | Factory-laminated insulation and cover board. | Combines ½-in HD ISO with polyiso insulation. |
| Nailbase / NB ISO | Insulated nailable surface for an appropriate assembly. | Polyiso combined with an oriented-strand-board surface. |
Tapered insulation needs a roof-wide layout
A tapered plan coordinates high points, crickets, drain sumps, scuppers and transitions around curbs. The available board slope is not automatically the correct design slope. Drain positions, structural slope, code requirements and the selected membrane all affect the final plan.
Specify R-value and attachment together
Use the current thermal-resistance data for the selected thickness and board combination. Mechanical attachment, insulation adhesive and loose-laid configurations are system-dependent. Fasteners and plates must suit the deck; vapor-control needs should be assessed for the building’s interior conditions.
HD ISO is a cover board, not a replacement for the roof membrane. Published impact, fire and wind performance belongs to the tested roof assembly. The board’s listed R-value is not the R-value of the complete roof.
Product references and qualification notes
Confirm the current product, installation requirements and written warranty for your property. Manufacturer testing and approvals apply to the listed assemblies and conditions.
ROOF SYSTEMS · GULF COAST
Plan the roof from the deck upward
This illustrates the decisions in a roof proposal; it is not an installation detail.
Roof deck and existing conditionsCondition, moisture, support and attachment.
Insulation and tapered drainageThermal requirements, drain locations and the proposed slope layout.
Specified cover boardCompatibility, surface protection and the complete approved assembly.
Membrane, flashings and perimeterCoordinate penetrations, edges, access routes and written coverage.
A new membrane alone does not define a drainage correction. Ask the proposal to show how water reaches outlets and how the roof height affects curbs, edge metal and adjacent construction.
ROOF SYSTEMS · GULF COAST
Questions about this roof system
Will adding tapered insulation fix every ponding area?
A designed tapered layout can improve drainage, but drain locations, deck deflection, perimeter heights and adjoining construction also matter. The roof assessment should establish the cause and document the proposed drainage path.
What is the difference between polyiso insulation and a cover board?
Standard polyiso primarily provides thermal insulation. A cover board supplies a specified surface above the insulation and can add resistance to rooftop traffic and other loads as part of a tested assembly. Some composite boards combine both layers.
ROOF SYSTEMS · GULF COAST
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