White Roof Membrane Reflactance

Converting from a dark to a highly reflective roof.

White roof membrane reflactance.

Over the last ten years new information has emerged about reflective roofing. Total annual air conditioning savings were estimated to be 7 200 or 7 2 cents per square foot. With a lower temperature increase of the cooler roof is a reduced heat transferred to the insides. Green building council and has been mandated by government officials in chicago.

White thermoplastic membrane roofs pvc and tpo are inherently reflective achieving some of the highest reflectance and emittance measurements of which roofing materials are capable. Citation needed a roof made of white thermoplastic for example can reflect 80 percent or more of the sun s rays and emit at least 70 of the solar. Commonly referred to as cool roofing it has received a stamp of approval from the state of california which has adopted its use in its building codes. White or reflective roofs have been in use for the past 15 years.

What the industry knows today is very different from what it knew when white roofing was touted as a. Reformulate or coat black membranes to make them reflective. Known simply as cool roofing this process is designed to reduce the solar radiation. The environmental benefits of exposed membrane low slope roofing systems with high solar reflectance and thermal emittance have been established by the cool roof rating council crrc lawrence berkeley national laboratory and others.

Below are the results. Single ply membranes are pre fabricated sheets rolled onto the roof and attached with mechanical fasteners adhered with chemical adhesives or held in place with ballast gravel stones or pavers. The membrane can be used for new roof installation or as a replacement roof. Comparing modeled energy costs for a white highly reflective roof membrane such as gaf everguard tpo versus those for a dark absorptive membrane such as epdm the following annual savings are projected for the 125 000 sq ft.

In 2017 more than 3 000 city rooftops were painted using both white lime and a special reflective coating. It has become a leed leadership in energy and environmental design standard of the u s. There s much more to selecting a roof membrane than color but it s not a black and white decision. The roof was then replaced with a white reflective sarnafil roof membrane and the test was run again during the same time of year as the previous test.

A reflective roof membrane has the capability to reflect the sun s uv and infrared rays away from the building allowing the roof temperature to increase only by 12 o f which is much lower than the 78 o f increase from the traditional black roof. Roofkit 10 by 100 foot white tpo reinforced membrane is 45 mil thick and is for use on flat roof surfaces. How they can be made cool. Built up roofs consist of a base sheet fabric reinforcement layers and usually a dark protective.