Radiant Barrier Roof Sheathing Facts

Emissivity ratings are between 0 and 1with 0 being the optimal performance for a low e material.

Radiant barrier roof sheathing facts.

A radiant barrier is a layer of material generally on the underside of your roof deck that acts as a shield to the radiant energy literally letting solar energy bounce off your rooftop and back into the atmosphere. Thus less heat is transferred into living areas through the ceiling. Some of thefacts they list are. Radiant barrier sheathing emits 3 5 of the heat it absorbs and can reducesummer heat gain in the roof from 16 to 42.

A radiant barrier works best when it is perpendicular to the radiant energy striking it. In the heat of the summer radiant barrier sheathing will keep the maximum attic temperature up to 30 cooler than attics with standard sheathing. Your radiant barrier makes the roof deck sheathing invisible from the attic. A radiant barrier reduces the radiant heat transfer from the underside of the roof to the other surfaces in the attic.

This basically allows for wood rot to continue and inspectors have a more difficult time finding areas of concern. Florida solar energy center conducted a study on radiant barrier and shingle temperatures and found that the roof increased in temperature by only about 5 degrees at the hottest point of the day when the heat was entering and exiting the roof simultaneously. This can result in energy savings in cooling costs up to 10. Also any water leak will fall onto the backside of the radiant barrier and roll down the slope until it reaches the eaves soffits.

A cooler attic space means less heat moving to the cooler space below the attic. The radiant barrier reflects 95 of the radiant heat back to the roofing materials which then emits over 90 of the heat out the roof almost instantly. Multiple studies have confirmed that a radiant barrier is a worthy addition to a home s thermal envelope. Radiant barrier has been shown to decrease ceiling heat gains by up to 42 in certain tests.

The hot roof material then radiates its gained heat energy onto the cooler attic surfaces including the air ducts and the attic floor. But on the bright side. Installed in over 1 5 million homes in the united states lp techshield panels also lower attic temperatures up to 30 f. The hotter it gets the better radiant barriers work.

Hot air has a tendency to rise under most circumstances so it doesn t take a whole lot of reflection to do the job. A shiny material is generally all that you need though obviously some materials are better than others. Thermostat reflects up to 97 of the sun s radiant heat and that keeps it from being absorbed into the attic. In selecting your radiant barrier sheathing make sure that the label indicated that the productemittance is less than 0 1 as measured by astm 1371.