TOPIC 04

DensDeck® Roof Boards

Chapter 01: Why DensDeck® Roof Boards?

The right choice for resilient roofs

Check out this video to see how DensDeck® Roof Boards can help your roof reach its maximum life expectancy ... and why they outperform alternatives.
CHAPTER 02: DENSDECK® ROOF BOARD PERFORMANCE

Strength and durability

Compressive strength measures the amount of force a material can withstand before it cracks or breaks. The higher it is, the better a material will be at resisting punctures, supporting static equipment and handling the burden of foot traffic.

Flexural strength determines the flex or bending properties of a material. Higher flexural strength can increase a cover board’s flute-span capability while guarding against wind uplift. This helps protect your roof from membrane delamination and fastener withdrawal.

Flute-span capability is a material’s ability to handle loads across a metal roof deck’s gaps (flutes) where it is not supported by the top flange.
A rendering of five roofing system layers shows DensDeck® Roof Board in gray under the membrane. Chart to the right has “DensDeck® Roof Boards” in text across the top. It shows their compressive strength ranges from 900 to 1,800 PSI. Their flexural strength ranges from 100 to 200 LBF. Their flute-span ranges from 8 to 18 inches.

Benefits to your roofing system and the entire building

Dumbbell Icon depicting strength and durability

Enhanced durability

The compressive strength of DensDeck® Roof Boards helps fight the risk of punctures from heavy foot traffic and dropped tools during maintenance. This means fewer callbacks for you and more satisfied stakeholders.

Increased life expectancy

Cover boards extend the life of a roof. 86% of single-ply roofs with a cover board met owner life expectancy compared to only 52% of roofs without a cover board.¹

Noncombustible

DensDeck® Roof Boards are noncombustible per ASTM E136. Their gypsum core and fiberglass mat facers help slow the spread of flames and smoke.

Consistent substrate

DensDeck® Roof Boards’ gypsum core helps provide a rigid, consistent substrate for attaching photovoltaic systems and more rooftop installations.

Improved acoustics

Using rigid gypsum cover boards like DensDeck® Roof Boards can help absorb sound, which means occupants hear less outside noise.

SOURCE:

1 FMI Roof Cover Board Survey completed in May 2020. Actual results may vary.

CHAPTER 03: THE FOUR DIMENSIONS OF PROTECTION

Watch how DensDeck® Roof Boards are put to the test

Fire resistance

One of the most dangerous threats to a commercial low-slope rooftop is the risk of catching fire. See how DensDeck® Roof Boards perform in fire testing.

Wind resistance

When heavy winds move over and around a building, they create low pressure above the roof. Wind uplift can cause membrane delamination and fastener withdrawal. DensDeck® Roof Boards give you a rigid base of support, a superior bonding surface and enhanced strength to mitigate damage.

Puncture resistance

While small punctures may not look threatening, they can lead to serious problems over time. See how DensDeck® Roof Boards outperform HD ISO in puncture tests.

Hail resistance

DensDeck® StormX® Prime Roof Board was the first cover board to be FM classified for Very Severe Hail (VSH) in approved single-ply assemblies. It helps provide impact protection to both the membrane and insulation of your roofing system.

CHAPTER 04: DENSDECK® ROOF BOARDS VS. THE OTHERS

See how they stack up

Durable low-slope roofs should be able to stand strong against wind uplift, impact from flying debris, punctures, the spread of fire and extreme hail. They should also be able to support heavy equipment like HVAC systems and solar panels.
COMPARE HD ISO
COMPARE OSB/PLYWOOD
COMPARE CEMENT
Option A
Densdeck Roof Boards
Fiberglass Mat Gypsum Substrate
Option B
HD ISO HIGH-DENSITY
Foam Insulation
Compressive Strength
Higher compressive strength helps resist punctures, support static equipment, and protect projects from heavy foot traffic.
900 - 1,800 PSI
80 - 120 PSI
Thermal Resistance
The higher the thermal resistance, the lower the heat loss.
1.1 R-VALUE PER INCH
4+ R-VALUE PER INCH
Fire Resistance
Just because a material is fire-resistant doesn’t mean it can’t burn.
NONCOMBUSTIBLE
FIRE-RESISTANT
Mold Resistant
The ability of a material or surface to discourage mold growth.
FM Approved For Very Severe Hail (VSH)
VSH starts at 2 inches but may exceed 4 inches in diameter.

Densdeck StormX Prime Roof Board

Option A
Densdeck Roof Boards
Fiberglass Mat Gypsum Substrate
Option B
HD ISO HIGH-DENSITY
Foam Insulation
Compressive Strength
Higher compressive strength helps resist punctures, support static equipment, and protect projects from heavy foot traffic.
900 - 1,800 PSI
1,500 - 2,500 PSI
Thermal Resistance
The higher the thermal resistance, the lower the heat loss.
1.1 R-VALUE PER INCH
0.6 R-VALUE PER INCH
Fire Resistance
Just because a material is fire-resistant doesn’t mean it can’t burn.
NONCOMBUSTIBLE
FLAMMABLE
Mold Resistant
The ability of a material or surface to discourage mold growth.
FM Approved For Very Severe Hail (VSH)
VSH starts at 2 inches but may exceed 4 inches in diameter.

Densdeck StormX Prime Roof Board

Option A
Densdeck Roof Boards
Fiberglass Mat Gypsum Substrate
Option B
HD ISO HIGH-DENSITY
Foam Insulation
Compressive Strength
Higher compressive strength helps resist punctures, support static equipment, and protect projects from heavy foot traffic.
900 - 1,800 PSI
1,000 - 1,250 PSI
Thermal Resistance
The higher the thermal resistance, the lower the heat loss.
1.1 R-VALUE PER INCH
0.8 - 1.2 R-VALUE PER INCH
Fire Resistance
Just because a material is fire-resistant doesn’t mean it can’t burn.
NONCOMBUSTIBLE
NONCOMBUSTIBLE
Mold Resistant
The ability of a material or surface to discourage mold growth.
FM Approved For Very Severe Hail (VSH)
VSH starts at 2 inches but may exceed 4 inches in diameter.

Densdeck StormX Prime Roof Board


CHAPTER 05: A BOARD FOR EVERY DESIGN INTENT

Three options based on your performance needs

If a building owner is going to resell the building immediately, they might not care how long the roof lasts or how resilient it is. But if they’re going to treat the building as a long-term asset, including a DensDeck® Roof Board will help it last as long as possible.
A three-column chart shows three types of DensDeck® Roof Boards. In column one DensDeck® Roof Board is shown in a five-layer rendering in gray. Underneath it states, “First of its kind in roof protection. Georgia-Pacific redefined roof boards in 1987 with DensDeck® Roof Board. This innovative cover board provides stronger puncture protection and is noncombustible as a result of its gypsum core. Since 1987, Georgia-Pacific has continued innovating industry-leading high performance roof boards. Installation method: For mechanically fastened assemblies.” In column two DensDeck® Prime Roof Board is shown in a five-layer rendering in green with fasteners on top. Underneath it states, “Enhanced moisture resistance. Building on the legacy of DensDeck® Roof Board, DensDeck® Prime Roof Board offers even more strength with enhanced moisture resistance for adhered roofing assemblies. Installation method: For fully adhered, partially adhered and mechanically fastened assemblies. + Enhanced moisture resistance.” In column three DensDeck® StormX® Prime Roof Board is shown in a five-layer rendering in green. Underneath it states, “For extreme wind and hail conditions. With enhanced hail, wind and puncture resistance that defies the most extreme weather, DensDeck® StormX® Prime Roof Board is FM classified for VSH in approved single-ply membrane assemblies. Installation method: For fully adhered, partially adhered and mechanically fastened assemblies. + FM Classified for VSH in approved single-ply membrane assemblies.
Chapter 06: How the DensDeck® team can help

Support when you need it

From helping you talk to building owners to providing technical resources to field support—we’re here to help. Watch the video to hear what you get when you work with Georgia-Pacific Gypsum products.

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