How Much Do Baffels Add To R Value Of Roof

All these have r values ranging from r 3 2 to r 3 8 per inch.

How much do baffels add to r value of roof. R value is a measure of insulation s ability to resist heat traveling through it. Insulation level are specified by r value. Closed cell spray foam has a far better r value per inch than other less effective insulations like cellulose fiberglass or even open cell foam. Even with a 3 12 2 4 truss you are looking at a minimum r15 at the farthest edge.

The higher the r value the better the thermal performance of the insulation. Stukinftw the rigid foam baffles can be fastened with angled nails or screws driven tight against the face of the foam and up into rafters on either side. The most common blown in material used but it can rot and grow moldy if exposed to moisture. Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials.

Fibers from recycled post consumer paper that are treated for insect and fire resistance. Baffles establish a channel for air to circulate between the insulation and the roof sheathing. Closed cell spray foam insulation. By installing the baffles properly you can increase the r value all the way out to the exterior sheathing.

Generally 40 of the total assembly r value should be above the roof deck. R value of various materials. You should of course see the manufacturer provided technical data sheet for the r value of specific products. High r value unvented roof assemblies will require a proportionally larger amount of insulation above the roof deck for condensation control.

You don t need much to hold them into place just enough to temporarily hold them until a bead of spray foam sealant applied along each edge sets up and does the permanent holding. The higher the r value the greater the insulation performance. 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. For a very good introductory overview article on r value see r values over at the website of.

When determining how much insulation you need don t guesstimate calculate. Fibers from rock or recycled slag from blast furnaces. Recommended home insulation r values. As listed in the definition above the baffle is meant to regulate the flow of air.

More insulation is needed above the roof deck in colder climates and where indoor relative humidity is above 35 in winter. The r value is r 3 5 to r 3 6 per inch so filling a 2 4 cavity yields about an r 13. Know exactly how much you need with our project calculators.