How to Reduce Heat in a House's Roof with Double Roof System

When building in warmer climates builders must consider how to reduce heat in their clients’ homes, making their living spaces as comfortable as possible. Ultimately, the goal is to reduce the amount of energy required to cool the space, and one way to do that is in the roof assembly with a ventilated double roof system. Let’s take a look at how this system works—and how LP® TechShield® Radiant Barrier sheathing can contribute to a more energy-efficient build.

What is a Ventilated Double Roof System?

A ventilated double roof system is a roof assembly that includes a series of two types of sheathing—one on top of the other—to allow for ventilation. 

In comparison, an unvented attic involves a roof assembly in which insulation is placed against the roof deck. In this case, a radiant barrier cannot be used because it requires an air gap between the insulation and the sheathing. 

However, a ventilated double roof system allows for the air gap, which means radiant barrier sheathing, like LP TechShield Radiant Barrier, can function properly and air can escape.

Which Climate Areas Benefit from Ventilated Double Roof Systems in Homes?

Areas of the United States that experience consistent bouts of extreme heat require special consideration when it comes to home design. Ventilated double roof systems can make a significant impact for residents of warmer states, such as Arizona, Florida and California.

Some of these areas can also experience high humidity, making a water-resistive barrier critical as well. LP WeatherLogic® Air & Water Barrier, which can be used for roof sheathing, becomes an important part of double roof systems in these areas, helping to ensure that water and air have a way to escape.

By designing ventilated double roof systems, builders in climates with extreme heat can give their clients not only a more comfortable home but a more efficient home.

Benefits of a Double Roof 

A ventilated double roof’s benefits start with energy efficiency—with this type of roof, less energy is required to cool the attic. This can lead to energy savings for the homeowner and a more comfortable space. Additionally, this type of roof also reduces the temperature on the insulation in place and on the shingles, which helps contribute to energy efficiency.

A double roof system also contributes to a home’s longevity. The two may not seem connected, but this type of roof system is a great way to create redundancies in a home’s construction, which helps mitigate potential issues. 

For example, if roof sheathing leaks in a typical roof assembly, it may be hard to discover the issue quickly. This could lead to greater damage, including structural damage and loss of energy efficiency from wet insulation.

However, with a double roof system, one layer of sheathing can be dedicated to moisture management (such as LP WeatherLogic Air & Water Barrier). This will help direct water away from the assembly, while the other parts of the assembly can continue working effectively.

In addition, LP TechShield Radiant Barrier does its part in moisture management with VaporVents™ technology, designed to allow any trapped moisture to escape during and after installation. It also helps builders meet energy codes due to its contribution to a home’s energy efficiency.

Building in a climate that deals with extreme heat? Read more about achieving energy efficiency in these areas.