MAX Compared to Polyiso

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MAX Compared to Polyiso


There are many myths about the performance of Foam-Control MAX compared to Polyiso insulation.
Consider these facts and make an educated decision


Foam-Control MAX   Polyiso
Closed Cell Polystyrene Foam Filled with Air.
Foam-Control MAX is a closed cell foam. It is manufactured from expanded polystyrene resin which is molded into blocks. Foam-Control MAX contains air within the closed cells.
Closed Cell Polyisocyanurate Foam Filled with an Unknown Gas.
Polyiso insulation is a closed cell foam. It is manufactured from methylene diphenyl diisocyanate (MDI), polyester-derived polyol, blowing agents, and other additives. Polyiso insulation contain gases other than air within the closed cells.
ASTM C578 Standard Compliance.
Foam-Control MAX is manufactured in compliance with ASTM C578, “Standard Specification for Rigid, Cellular Polystyrene Thermal Insulation”. Foam-Control MAX is recognized in UL evaluation report UL ER11812-05.
ASTM C578 Standard Compliance.
Polyiso is manufactured in compliance with ASTM C1289, “Standard Specification for Faced Rigid Cellular Polyisocyanurate Thermal Insulation Board”. There is limited recognition of Polyiso in either UL or ICC-ES evaluation reports.
R-value: Stable Long-Term.
The trapped gas in the cells of Foam-Control MAX is air. The air in Foam-Control MAX is in balance with the atmosphere during the life of the foam. The result is Foam-Control MAX has a stable R-value over its lifetime.
R-value: Loses R-value over Time.
The trapped gases in the cells of Polyiso assist to provide an initial high R-value. During the life of the Polyiso, air from the atmosphere diffuses in and the trapped gases diffuse out. The result is Polyiso loses R-value over its lifetime.
R-value: Cold Temperature.
The R-value of Foam-Control MAX increases as temperatures drop. This means the Foam-Control MAX has improved performance in cold climates.
R-value: Cold Temperature.
The R-value of Polyiso has been shown to drop significantly as temperatures drop. This means the performance of Polyiso is well below the claimed performance in cold climates.
Versatilty.
Foam-Control MAX is manufactured in any thickness to meet project R-value requirements. Custom taper panels, flute filler, and one piece valleys readily available at low cost.
Versatilty.
Polyiso is manufactured in limited thicknesses. Tapered panels have limited availability at high cost. Custom flute filler and one piece valleys not available.
Dimensional Stability.
Foam-Control MAX has exceptional dimensional stability when exposed to extreme temperature and moisture conditions.
Dimensional Stability.
Shrinkage, curling, and cupping have been observed for Polyiso exposed to extreme temperature and moisture.
Vapor Permeance.
The vapor permeability of Foam-Control MAX ranges from 2.5 to 5.0 perms for a 1 in. thick material. Film faced Foam-Control MAX is available when low permeability is needed.
Vapor Permeance.
The vapor permeability of Polyiso generally ranges from 1.5 to 4.0 perms for a 1 in. thick material. Aluminum faced Polyiso is available when low permeability is needed.
The R-value of Foam‑Control MAX increases as the temperature gets colder. In contrast, the R‑value of Polyiso drops when temperature conditions are cold.

PLUS+ Powers Up at Cold Temperatures

  Foam-Control MAX Compared to Polyiso