Hybrid Flash And Batt Insulation Roof

Let us start by considering the benefits and costs of spray foam insulation vs.

Hybrid flash and batt insulation roof.

In a standard 2x6 wall they will spray 1 of closed foam inside the wall cavity and then fill the rest with cellulose. The installed r value is approximately r 12 for two inches of high density spray foam 2 0 pcf and r 13 for three and a half inches of fiberglass batt totaling r 25. We launched our system three years ago and there wasn t much conversation. The hybrid foam installation method combines energy efficient spray foam with conventional insulation to create a lower cost alternative to using foam alone.

The first problem was that one inch of closed cell spray foam insulation wasn t enough to keep the temperature on the surface of the foam above the dew point due to the temperature or conditions the house was experiencing. Flash and batt insulation is one example of a new technique being implemented by insulation contractors. Matt girand a product and program director for residential insulation with owens corning which offers a hybrid air sealing and insulation system says the adoption of air sealing and flash and batt techniques gained momentum slowly but has become widely accepted. I can foresee many potential building science issues with.

The idea is to get all the benefit of the air sealing but then to get the rest of the r value from the much less expensive cellulose. Many insulation companies in our area have begun to sell hybrid insulation systems. For this reason in some markets contractors are turning to hybrid insulation systems often referred to as flash and batt insulation. Fiberglass devoured the insulation industry in the 1970s for obvious reasons.

Foam it green spray foam insulation can be combined with other insulation to make a powerful hybrid method. All insulation above roof deck the big deal with unvented roof assemblies is to control condensation or moisture accumulation on the underside of the roof sheathing. Avoiding flash and batt condensation problems. In this case there were two problems.

Flash and batt is a hybrid insulation approach combining fiberglass insulation and closed cell spray foam. To fill a 2 x 6 inch empty wall cavity first add a flash coat of closed cell foam on the exterior wall to a thickness of 1 2 inches then take a low density batt to fill in the space before the drywall is. Flash fill flash batt using 2 different types of insulation for lower cost. If all of the insulation is on the top of the roof sheathing this is pretty much a no brainer.

Fiberglass insulation and other standard products such as cellulose wool and other mass type insulation. Using two dimensional heat flow analysis with thermal bridging effects and average framing factors the r value decreases from an installed insulation r value of.