R Value Of Green Roof

Every construction design architect engineer a e knows a material s r value is an important factor when specifying insulation products with many regulations requiring minimum values for wall ceiling and roof assemblies.

R value of green roof.

These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. R value minke et al. Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials. R s landscaping did the job here.

R value is a measure of insulation s ability to resist heat traveling through it. R value of various materials. Increased r value a measure of the resistance of a material to heat flow of the roofing system along with reduced temperatures on the roof lessen hvac loads resulting in energy cost savings. Insulation level are specified by r value.

2003 evapotranspiration schmidt 2003 berghage et al. Neglected thermal storage moisture dependent performance and. The plants in a green roof absorb water through their roots and then use surrounding heat from the air to evaporate the water while some roofs can reach temperatures of up to 90 f in the summertime these two features can allow. For example a code may require that skylights have only an r 5.

Determining insulation r value accuracy. Let s imagine a roof that should have an r 30 value. Hardy sedums are most popular for green roofs because they thrive in a soilless growing medium and are drought tolerant. At 40 pounds each the trays are heavy and meant to be installed by a certified contractor.

The higher the r value the better the thermal performance of the insulation. 1982 wong et al. Traditional roof green roof n sensible et r q q q substrate 0 where r n net radiation q sensible sensible heat flux due to convection q et. For example if you have a type of insulation that has an r value of r 5 per inch of thickness you will need a depth of 6 inches of this insulation installed in your attic to reach r 30 if you live in zones 2 or 3.

A green roof may improve property values and marketability especially in urban areas with little green space. Codes may specify a smaller r value for these components compared to the rest of the roof. For a very good introductory overview article on r value see r values over at the website of. See how this roof went from bare to bountiful plus the latest on living roof diy options.

R value of about 2 5 ft f btu. Recommended home insulation r values. Green roofs reduce the temperature of the building and the surrounding air in multiple ways. Green roofs can have lower energy cost than conventional roofs and sometimes compete well against white roofing effects are more pronounced for lodging buildings.