DensDeck Roof Board product rendering - product is laying flat
DensDeck Roof Board product rendering - product is laying flat

DensDeck® Roof Board

  • Rigid gypsum roof board used as a cover board, thermal barrier, or substrate board in commercial low-slope roof assemblies.
  • Commercial roofing board used as a cover board, thermal barrier, or substrate board.
  • Noncombustible with zero flame spread and zero smoke developed when tested in accordance with ASTM E84.
  • Resists punctures that occur from things like maintenance foot traffic or dropped tools.
  • Typically used for mechanically fastened assemblies.

Product Details

DensDeck® Roof Board is designed to address persistent challenges inherent in commercial roofing assemblies, including fire resistance, durability and dimensional stability when installed in a properly designed roof assembly. With a non-combustible gypsum core, it has 0 flame spread and 0 smoke developed when tested in accordance with ASTM E84 and CAN/ULC-S102. It is also UL classified for resistance to both external and internal fire sources per ANSI/UL 790 and ANSI/UL1256.

Being a strong rigid board, it can enhance a roof’s ability to resist wind uplift forces that can cause fastener pull-through. DensDeck® resists impact from repeated events like maintenance foot traffic, dropped tools, and flying debris. DensDeck® can serve as a thermal barrier, installed below the insulation to protect against internal fires. In most assemblies it will be used as an insulation overlayment (membrane underlayment) or cover board. In other assemblies it will serve both of these roles in the same system.

FEATURES AND BENEFITS

  • Unrivaled Durability: Fiberglass mats bonded to a dense gypsum core provide wind uplift resistance, fire protection, and superior load-bearing capabilities.
  • Mold Resistant: Achieves the highest possible score of 10 on the ASTM D3273 mold test.1
  • Enhanced Stability: Delivers resistance to job-site damage, deterioration, and ensures long-lasting performance across various roofing environments.
  • Wide Compatibility: Compatible with built-up, modified bitumen, single-ply, metal systems, tile, wood shingles, shakes, spray foam, and more roofing applications.

Product Specifications

PERFORMANCE ATTRIBUTES

R Value°F•ft2•hr/BTU (m2•K/W): .28
Humidified Deflection≤1/8″ (3 mm)
ASTM TypeASTM C473; ASTM E661; ASTM E96; ASTM C518; ASTM C1177; ASTM C473
Flame Spread & Smoke Development(ASTM E84): 0/0
Fire RatingType X
Mold Resistance(10/10)
Flexural Strength, parallel, lbf. min. (N)​≥40 (178)
Flute Spanability22-5/8” (67 mm)
Permeance, Perms (ng/Pa•S•m2 )​>50 (>2850)
Linear Variation with Change in Temp., in/in/°F (mm/mm/°C)​8.5 x 106 (15.3 x 106)
Linear Variation with Change in Moisture6.25 x 106
Water Absorption, % max3<10
Compressive Strength, psi nominal​900
Surface Water Absorption, grams, nominal​<2.5
Bending Radius​5’ (1524 mm)

PHYSICAL PROPERTIES

Lengthstandard: 8’ (2438 mm) ± 1/4” (6.4 mm)
Width standard: 4’ (1219 mm) ± 1/8” (3 mm)
Thicknessnominal: 1/4” (6.4 mm) ± 1/16” (1.6 mm)
Weightnominal: 1.2 (5.9)
EdgeSmooth Wall; Square Edge; Tapered Edge

PERFORMANCE ATTRIBUTES

R Value°F•ft2•hr/BTU (m2•K/W): .56
Humidified Deflection≤1/8″ (3 mm)
ASTM TypeASTM C473; ASTM E661; ASTM E96; ASTM C518; ASTM C1177; ASTM C473
Flame Spread & Smoke Development(ASTM E84): 0/0
Fire RatingType X
Mold Resistance(10/10)
Flexural Strength, parallel, lbf. min. (N)​≥80 (356)
Flute Spanability25” (127 mm)
Permeance, Perms (ng/Pa•S•m2 )​>35 (1995)
Linear Variation with Change in Temp., in/in/°F (mm/mm/°C)​8.5 x 106 (15.3 x 106)
Linear Variation with Change in Moisture6.25 x 106
Water Absorption, % max3<10
Compressive Strength, psi nominal​900
Surface Water Absorption, grams, nominal​<2.5
Bending Radius​8’ (2438 mm)

PHYSICAL PROPERTIES

Lengthstandard: 8’ (2438 mm) ± 1/4” (6.4 mm)
Widthstandard: 4’ (1219 mm) ± 1/8” (3 mm)
Thicknessnominal: 1/2” (12.7 mm) ± 1/32” (.8 mm)
Weightnominal: 2.0 (9.8)
EdgeSmooth Wall; Square Edge; Tapered Edge

PERFORMANCE ATTRIBUTES

R Value°F•ft2•hr/BTU (m2•K/W): .67
Humidified Deflection≤1/8″ (3 mm)
ASTM TypeASTM C473; ASTM E661; ASTM E96; ASTM C518; ASTM C1177; ASTM C473
Flame Spread & Smoke Development(ASTM E84): 0/0
Fire RatingType X
Mold Resistance(10/10)
Flexural Strength, parallel, lbf. min. (N)​≥100 (444)
Flute Spanability28” (203 mm)
Permeance, Perms (ng/Pa•S•m2 )​>32 (1824)
Linear Variation with Change in Temp., in/in/°F (mm/mm/°C)​8.5 x 106 (15.3 x 106)
Linear Variation with Change in Moisture6.25 x 106
Water Absorption, % max3<10
Compressive Strength, psi nominal​900
Surface Water Absorption, grams, nominal​<2.5
Bending Radius​12’ (3658 mm)

PHYSICAL PROPERTIES

Lengthstandard: 8’ (2438 mm) ± 1/4” (6.4 mm)
Widthstandard: 4’ (1219 mm) ± 1/8” (3 mm)
Thicknessnominal: 5/8” (15.9 mm) ± 1/32” (.8 mm)
Weightnominal: 2.5 (12.2)
EdgeSmooth Wall; Square Edge; Tapered Edge

CERTIFICATIONS

Certifications may vary by production location, please contact local representative for more information.

1. The score of 10 in the ASTM D3273 test indicates no mold growth in a 4-week controlled laboratory test. The mold resistance of any building product when used in actual job site conditions may not produce the same results as were achieved in the controlled, laboratory setting. 

2. Tested in accordance with ASTM E661.

3. Tested in accordance with ASTM C1177.

Resources

5/8" DensDeck® Roof Board - EPD
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DensDeck® Gypsum Panels - HPD
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DensDeck® Gypsum Panels - HPD
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DensDeck® Roof Board Installation Guide
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DensDeck® Roof Board - Submittal
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DensDeck® Roof Board Technical Guide
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DensDeck® Roof Board Limited Warranty - USA (English)
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DensDeck® Roof Board Limited Warranty - USA (Español)
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DensDeck® Roof Board Limited Warranty - Canada (English)
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DensDeck® Roof Board Limited Warranty - Canada (Français)
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