I’m interested to know how many people be it architects, engineers and especially contractors actually know what and how a radiant barrier works AND if the product is being installed properly, ensuring its effectiveness. Sure, in Hawaii most people have heard of Tech-Shield… the most common radiant barrier sheathing on the market (shout out to LP) but, like most of us wonder… “what is my true purpose”?
I’ve heard a lot of shop talk on how Tech-Shield (radiant barrier sheathing) reflects radiant heat and keeps your home cooler… well, fortunately the later is true, IF it is installed with understanding AND measures are taken to ensure it’s NOT intended to reflect the heat. Rather, Tech-Shield is actually a “Low-E” product, meaning it actually doesn’t reflect heat at all, it absorbs it, much like any other roof sheathing, but the foil layer actually prevents emissivity… meaning heat transfer. In essence, Tech-Shield is your roof’s bullet proof vest for heat, it will take the heat bullet but not let it pass through to your home’s envelope.
A typical sheathing, absorbs the heat and that heat transfers to the rafters into the attic space, increasing the temperature significantly. So the trick here, is all about the proper installation of the radiant barrier, be it Tech-Shield or another product. So next time you’re faced with the burning (hot) question of whether or not your roof will have a radiant barrier… be sure to ask an even hotter one… do you know how the radiant barrier you’re about to install works…? Then throw in radiant heat transfer, low emissivity and HOT Dang… you’re talking some serious building science!