Roof Insulation U Values

Notes on the r value k values of different forms of asbestos.

Roof insulation u values.

U value has an inverse relationship to r value. The lower the u value the more insulation there is in a building element e g a floor ceiling or wall. R value of various materials. Therefore the less heatloss.

For more information see our articles and how to videos below. The higher the r value the greater the resistance and the insulating value. Consequently the higher the u value the more heatloss you have in the home. Find your zone on the map and then use the above insulation r value chart to determine the level of insulation you need to properly insulate your attic walls floors and crawlspaces.

These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. For a very good introductory overview article on r value see r values over at the website of. R value is essentially a product s resistance to heat flow which means that the higher the product s r value the better it is at insulating the home and improving energy efficiency. U values are the direct opposite representing the amount of heat that escapes through a material.

The higher the r value the better the thermal performance of the insulation. Knowing what r value and u values mean is key to following energy codes and to selecting products that best suit the climate zone you are building in. Notes to the table above. Insulation level are specified by r value.

A standardized insulation rating system ensures consistency with insulating materials rated in r and u values. R value is a measure of insulation s ability to resist heat traveling through it. U values are important because there are certain standards according to the building. R values represent resistance to the flow of heat.

The table below shows what levels of insulation are cost effective for different climates and. Column b is for other extensions upgraded existing thermal elements non exempt conservatories and conversion of unheated buildings. Reference table for u values u value is the coefficient of transmission i e the transmission of heat through the materials which compose the building s envelope or outer shell. Column a is for extensions where the existing dwelling s walls and roof u values are worse than 0 70 w m k in the walls and worse than 0 25 w m k in the ceiling.

Adversely u value measures the rate of heat transfer. You should of course see the manufacturer provided technical data sheet for the r value of specific products. Recommended home insulation r values. These can be supported with a detailed report.

Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials. For example a building with material with an r value of r 11 converts to an u value of 0 09 1 r or 1 11 0 09. The easiest way of getting a u value calculation is by using our free online u value calculator.