Impression Insulated Wall Panel

Impression is the flat panel profile from Green Span Profiles. It is an exterior wall panel. The profile uses the Heavy Stucco Embossment, shortened to HSE, on its exterior face. The embossed face gives the look of tilt-up concrete, and the panel weighs far less than tilt-up.

Impression is an insulated metal panel with a continuously poured-in-place polyisocyanurate foam core between two steel facers. It is used for the walls of commercial and industrial buildings, the same buildings served by insulated metal panel roofs and walls. The profile sits in the IWP Series of insulated metal wall panels.

Each panel covers 42 inches of wall. The exterior face is heavy embossed and the interior face is embossed or smooth.

Impression comes in four thicknesses, one coverage width and a range of lengths.

• Thickness: 2, 2.5, 3 and 4 inches
• Coverage width: 42 inches
• Length: 8'-0" to 40'-0"
• Exterior gauge: 24
• Interior gauge: 26

Versions differ in thickness, interior substrate, interior texture and finish. The thickness sets the insulation value and the panel weight. The 2-inch panel and the 4-inch panel share the same 42-inch coverage width and the same gauges. The interior face is chosen from the substrates, textures and finishes listed in the next section.

The exterior substrate is Galvalume. The interior substrate is Galvalume or stainless steel.

• Exterior finish: siliconized polyester or low-gloss PVDF
• Interior finish: polyester, siliconized polyester or plastisol (PVC)
• Exterior texture: heavy embossed
• Interior texture: embossed or smooth

The core is continuously poured-in-place polyisocyanurate insulating foam. It tests at 90% closed cells or more. Apparent density is 2.25 pcf. Compressive strength is 18 psi, tensile strength is 21 psi and shear strength is 16 psi.

The joint is the Green-Lock, an offset double tongue-and-groove. The joint is the same on every thickness from 2 to 4 inches.

The nominal R-value is R-8 per inch of thickness. The tested K-factor is 0.139 BTU-in/hr-ft2-F° at a 75° mean temperature. At a 35° mean temperature the K-factor is 0.129 BTU-in/hr-ft2-F°. Both figures come from ASTM C518 heat flow meter testing.

Panel R-values by thickness, at 75° mean and 35° mean:

• 2.00 inches: 15.25 and 16.35
• 2.50 inches: 18.85 and 20.23
• 3.00 inches: 22.45 and 24.10
• 4.00 inches: 29.65 and 31.85

Air leakage measures 0.0011 cfm/sf at 20 psf under ASTM E283. Water penetration under ASTM E331 is zero at 20 psf.

Panel weight depends on thickness and on the facer and liner gauges. Impression has a 24-gauge exterior facer and a 26-gauge interior liner. At the 42-inch width, the weights for that 24/26 combination are:

• 2 inches: 2.32 psf
• 2.5 inches: 2.42 psf
• 3 inches: 2.52 psf
• 4 inches: 2.73 psf

The weight chart covers panels up to 45 inches wide, at least 2 inches thick, with facer and liner of 26 gauge or heavier. Impression is one of the profiles on the chart, with MesaLine, CleanLine, VeeLine, ShadowLine, WaveLine, Stucco, Infinity, MaxLine and RidgeLine.

ASTM E84 surface burning results are flame spread under 25 and smoke developed under 450. The panel passed NFPA 285 testing for exterior non-load-bearing wall assemblies that contain combustible components. It is Class 1 Fire Rated under FM 4880 and Class 1 Approved under FM 4881.

Impact testing follows TAS 201, the Florida Building Code impact test procedure. Approvals issued for Impression are:

• Miami-Dade County Notice of Acceptance
• Florida Product Approval from the State of Florida
• Product Evaluation from the Texas Department of Insurance
• FM Approvals for Class 1 exterior wall systems

Structural performance is tested under ASTM E1592 and ASTM E72, and the results are published as load tables.

The bond tests cover fatigue, temperature cycling, humidity and pressure exposure. Four tests cover the panel, and none found damage to the bond between facer, core and liner.

• Fatigue endurance: 2,000,000 alternating cycles of L/180 deflection. No facer or liner delamination, no fracture of the foam core and no permanent set.
• Freeze/heat cycle: twenty-one eight-hour temperature cycles from –20° F to 180° F. No delamination, blistering or permanent set.
• Humidity endurance: 1,200 hours of 93% humidity at 158° F. No delamination, blistering or interface corrosion.
• Autoclave: exposure to 218° F and a pressure of 2 psig for 2½ hours. No facer or liner delamination.

Impression serves exterior walls where a concrete look is wanted without tilt-up construction. The 2-inch panel is the lightest at 2.32 psf. The 4-inch panel gives the highest insulation value of the four, at R-29.65 at a 75° mean temperature.

The 2.5-inch and 3-inch panels weigh 2.42 psf and 2.52 psf. They sit between them, at 18.85 and 22.45 at the same mean temperature. Stainless steel interiors and the three interior finishes suit different interior conditions. Smooth and embossed interior textures give a choice of interior appearance.

The Miami-Dade, Florida, Texas Department of Insurance and FM approvals cover projects that call for those listings.