Precision Series HWP

Precision Series HWP is the shallowest ribbed profile in the PAC-CLAD Precision Series, a line of concealed-fastener wall panels made by Petersen Aluminum Corporation. It is a metal wall panel with linear ribbing, and it can be combined with Highline and Box Rib profiles in one coordinated design.

HWPC is the clip-attached version of the same profile. HWP uses an extended fastening leg on the panel, and HWPC uses a clip. Neither version has fasteners exposed on the panel face.

The panel is 7/8 inch high. Two nominal widths are made, 12 inches and 16 inches. The rib count depends on the width.

• HWP, 12 inches wide: three-rib profile with a concealed extended fastener leg.
• HWP, 16 inches wide: four-rib profile with a concealed extended fastener leg.
• HWPC, 12 inches wide: three-rib profile with clip attachment.
• HWPC, 16 inches wide: four-rib profile with clip attachment.

Panels run horizontally or vertically on the wall.

Six base materials are listed for HWP: .032, .040 and .050 aluminum, and 24 gauge and 22 gauge steel. Steel can be G-90 galvanized (24 gauge) or Galvalume (22 gauge, stocked; 24 gauge, non-stocked), and Galvalume Plus is available. Aluminum is prime sheet to ASTM B209.

The finish is a Kynar 500 or Hylar 5000 fluorocarbon coating. The top side has a dry film thickness of 0.70 to 0.90 mil over a 0.25 to 0.31 mil prime coat, for a total dry film thickness of 0.95 to 1.25 mil. The bottom side carries a primer at a dry film thickness of 0.25 mil. Color is chosen from the PAC-CLAD color chart by gauge.

Maximum length is 30 feet for steel. For aluminum it is 22 feet on the through-fastened leg, and longer lengths are available on clip panels. Factory clips are listed for panels over 20 feet long to handle thermal movement.

The published test list for HWP is:

• ASTM E330, structural performance under load
• ASTM E283, air infiltration
• ASTM E331, water penetration
• ASTM E1592, structural performance of sheet metal panels by uniform static air pressure
• ICC-ES 5839

Florida building product approvals exist for Precision Series panels. The performance language for the series is an air penetration of .005 or less at 6.24 psf under ASTM E283, no water penetration at 12.48 psf for 15 minutes under ASTM E331, and no water penetration at 15 psf under AAMA 501. Negative wind uplift is tested under ASTM E330 at spans of 1 foot through 4 feet, double and triple spans, with a safety factor of 2.0 under the IBC and 1.65 under US Army Corps of Engineers criteria.

HWP is fastened through its extended leg to the wall supports. HWPC uses a clip, which allows expansion and contraction. Fasteners are galvanized steel, with dished washers or bonded neoprene. Zees span between beams or joists where the structural framing requires them.

Closures at the top of each elevation are composition or metal profiled closures in the same material and finish as the face sheet. Trim matches the panel material and finish, is press broken in lengths of 10 to 12 feet, and is formed only by the manufacturer or an approved dealer. Mitered trim corners are factory welded. Panels are formed in the factory by continuous rolling.

Sealants for vertical and horizontal joints are two-part polysulfide class B non-sag, one-part polysulfide without pitch or phenolic extenders, exterior-grade silicone, or one-part non-sag exterior polyurethane. Metal products do not contact treated lumber directly, and a vapor barrier goes over treated lumber before panels or flashings are installed.

The guide specification for HWP and HWPC is dated October 2016 and is written as Section 07412, Preformed Metal Siding, Concealed Fastening. Its finish warranty period is 30 years from substantial completion, covering color fading of more than 5 Hunter units under ASTM D2244, chalking beyond a No. 8 rating under ASTM D4214, and any cracking, checking, peeling or failure of paint to adhere to bare metal. Within the Precision Series, HWP is 7/8 inch deep, against 1-3/8 inch for Highline and Box Rib.

The published test reports are listed by width and attachment type:

• HWP 12 inch: ASTM E1592 in 24 gauge.
• HWP 16 inch: ASTM E283 and E331 for air and water, including AAMA 502.
• HWP 16 inch: ASTM E330 in .032, .040, 22 gauge and 24 gauge.
• HWPC 16 inch: ASTM E330 in .032, .040, 22 gauge and 24 gauge.

Load span charts cover HWP16 and HWPC16 in .032 and .040 aluminum and in 22 and 24 gauge steel, with negative load tables for all gauges and a perforated negative load chart for HWP16. ICC-ES Evaluation Report ESR-5839 and a Florida approval for siding apply.

Z-girt and wood substrate detail drawings are published in horizontal and vertical versions, in PDF and CAD. Details cover inside corner, outside corner, mitered outside corner, jamb, sill, splice, top-of-wall, top-of-wall tie-in, wall-to-soffit, window head, window jamb, window sill and installation. Wood Sill, Wood Window Head and Wood Window Jamb details are for wood substrate only.

PAC-CLAD colors use Kynar-based 70% PVDF coatings. The series is used on schools, hospitals, banks, sports facilities, office and industrial buildings, and residential buildings.