How Much Do Baffles Add To R Value Of Roof

R value of various materials.

How much do baffles add to r value of roof.

A new roof can increase home value but you might not see a 100 return on investment very few improvements if any offer a full recoup of money spent. Things to look for if you do it yourself. Recycled glass or sand that s melted and spun into fibers. Pull any existing insulation away from the edges of the attic where you will be putting up the baffles.

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. Although it generally won t hurt to add more the return on the investment decreases as the r value increases above r 50. Recommended home insulation r values. You will need a baffle for each space between the rafters.

As listed in the definition above the baffle is meant to regulate the flow of air. Baffles establish a channel for air to circulate between the insulation and the roof sheathing. Lighter in weight than cellulose or mineral wool but it settles more than those materials so you ve got to put in a thicker layer to get the protection you need. The higher the r value the better the thermal performance of the insulation.

R value is a measure of insulation s ability to resist heat traveling through it. You should of course see the manufacturer provided technical data sheet for the r value of specific products. But even if you don t see a huge financial return a new roof can make you more likely to get full asking price lower time on market and smoother negotiations. Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials.

As with attic floor insulation moisture and heat removal are the reasons for creating proper air. Even with a 3 12 2 4 truss you are looking at a minimum r15 at the farthest edge. Roughly 12 to 20 inches depending on the material used will provide an r 50 rating. If your roof rafters have been covered over with drywall or plywood you will have to remove it in order to install the baffles.

For a very good introductory overview article on r value see r values over at the website of. These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation.