by Derrick Hutchinson
When it comes to building resilience, the roofing coverboard is often an unsung hero. When installed as part of a properly specified and installed roofing system, this material helps prevent damage to roofs and greatly increase durability. However, very few architects and specifiers consider using these materials on their projects. This is a missed opportunity for both designers and building owners.
The purpose of roofing coverboards is simple—prevent damage from external forces and maximize building resilience. For example, a roof membrane may suffer punctures caused by hail, debris, or foot traffic. This may lead to leaks that spread across the roof and eventually cause internal damage. Even if the membrane stays intact, the insulation can puncture and lose a portion of its R-value. This leads to increased heating and cooling costs for building owners. Roofing coverboards are designed to protect membranes against this kind of damage.
Besides protecting the roofing membrane from direct impact, coverboards have many other benefits making them critical to any project. For instance, they enhance the structure in the event of wind uplift and fire. These added benefits have been proven in certified evaluations of roofs that have experienced extremely harsh weather.
Roofing coverboards also greatly improve the acoustics of a structure, making buildings more inhabitable and comfortable to occupy. When each of these benefits is looked at more closely, the value of roofing coverboards starts to become clearer.
Protecting against wind uplift
Wind uplift is the result of negative pressure on a roof caused by wind passing across it. The wind can also cause positive pressure on the interior side of the roof if there is an opening—such as an open or broken window or door—allowing wind to enter the building and build up pressure on the roof underside. The negative pressure created on the exterior of the roof, especially at edges and corners, causes a suction that can pull up elements securing it. The consequences of wind uplift varies depending on the type and age of the structure. The roof can be damaged, or it could be destroyed (possibly along with the building) if the roof is not equipped to handle high wind uplift.
In the event of a windstorm, such as a hurricane, a coverboard adds additional strength, which allows the building to withstand higher wind loads than a roof without one. High flexural strength is one quality that ensures a coverboard can do this. The bond of the membrane to the coverboard also plays a large part in withstanding a windstorm. The higher the peel resistance of the membrane from the coverboard, the better its chances are against high winds. Peel resistance, combined with a higher flexural strength, ensures the coverboard is well-suited for all locations, especially high-wind-zone regions.