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Beyond the roofing membrane: extending the life of your roof with a cover board

The main function of a building’s roof is to protect its contents, including the people that work and live inside it, from weather conditions. A roof consists of several components that need to work together efficiently and in a consistent way to offer a long-term solution. While the roofing membrane is often the top and therefore most visible layer of the roof build-up, what is below it has a significant impact to the overall roof performance.

Insulation is one such key component, which is often one of the most expensive of a roof assembly. Extreme weather conditions, such as hail or heavy snowfalls, or frequent foot traffic on the roof can damage the insulation layer, resulting in a reduction of the roof’s thermal performance, which in turn would cause an increase in energy costs. From a life-cycle cost perspective, it is a smart move to protect the insulation layer with cover boards.

In addition, the increasing demands on roofing systems in terms of performance and durability, or to accommodate PV roofs or green roofs -which require frequent maintenance- have highlighted the crucial role that cover boards play to meet these challenges.

Cover boards are semi-rigid, relatively thin boards that are usually installed over the insulation to provide added impact protection, separation and support to the roofing membrane. They are available in a wide variety of materials, such as PIR-based, gypsum-based, cement-based, wood based, etc. They add strength to the entire roofing system, improving its overall performance.

Cover boards can be used in all types of roofs, both on new build and renovation projects. They can be used in roof refurbishment projects on top of the old roofing membrane, providing a suitable substrate for the installation of the new membrane. In short, including a cover board in the roof build-up makes the whole roofing system more robust and contributes to extend its service life.

In combination with quality insulation, cover boards also provide other benefits: they offer better moisture protection, improve acoustics and can even help achieve a better wind uplift performance and enhanced fire resistance. When selecting a cover board, however, it is important to keep in mind which properties are most crucial for the job and the type of roof system desired. Knowing the properties of each cover board helps when selecting one that will provide the best value for the building. Some building codes may also dictate certain fire and wind-uplift performance and including a cover board may help achieve these requirements.

Besides offering high quality roofing membranes, Firestone’s product range includes other roofing components that are fully compatible with each other, further enhancing the overall performance of the roofing system. The ISOGARD™ HD cover board is one such component. It is a high-density, closed-cell, 12.7 mm thick polyisocyanurate (PIR) cover board consisting of a polyiso foam core laminated on both sides to a coated fiberglass facer.

ISOGARD™ HD is designed to spread the load and protect the insulation boards under the roofing membrane. It is easy to cut and handle for quick fabrication around roofing details such as drains or other penetrations, reducing installation time and labor costs. It is also very lightweight: a single 1.22 m x 2.25 m ISOGARD™ HD cover board weighs only 5 kg, meaning easy manipulation and placement. It has the highest thermal performance of any 12 mm cover board and is resistant to extreme weather conditions.

The ISOGARD™ HD cover board provides excellent moisture resistance and does not support the growth of mold. The foam technology does not contribute to the depletion of the ozone layer (zero ODP) and uses a HCFC-free blowing agent.

With a compressive strength of more than 800 kPa (more than 5 times that of a standard PIR insulation board), ISOGARD™ HD adds strength to the entire roofing system and helps it absorb the effects of hail, foot traffic and other potentially damaging impacts.  It also brings flexibility for the application of roofing membranes on top of no matter what kind of insulation is used underneath.

Want to learn more about how you can extend the service life of your roof with Firestone’s ISOGARD™ HD? Consult our product page and do not hesitate to contact us for more details.