When you install a rain screen or exterior insulation, such as rigid foam, on your windows or doors, you need to install bucks to ensure that your windows or doors and your rain screen or insulation are aligned with each other. While wood is the most commonly used material for window or door bucks, there is now a greener alternative that will increase your home’s efficiency. This is called ThermalBuck.
ThermalBuck is made from high-density polystyrene coated with polyurethane and polyuria and is said to have better thermal insulating capabilities than wood, which also has a lower R-value and can warp and shrink over time. ThermalBuck is even durable enough to withstand hurricane-strength winds. This makes ThermalBuck a greener alternative you can consider.
ThermalBuck was invented by John Brooks of Brinc Building Products in Pennsylvania, and it comes in four sizes to accommodate the different thickness measurements of insulation and rain screens.