If all of the insulation is on the top of the roof sheathing this is pretty much a no brainer.
Hybrid flash and batt insulation roof.
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.
For this reason in some markets contractors are turning to hybrid insulation systems often referred to as flash and batt insulation.
I can foresee many potential building science issues with.
It s a great way to get the benefits of closed cell spray foam and save.
Flash and batt is a hybrid insulation approach combining fiberglass insulation and closed cell spray foam.
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.
All of the rigid insulation board products work.
In this case there were two problems.
Flash fill flash batt using 2 different types of insulation for lower cost.
Avoiding flash and batt condensation problems.
Foam it green spray foam insulation can be combined with other insulation to make a powerful hybrid method.
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.
In a standard 2x6 wall they will spray 1 of closed foam inside the wall cavity and then fill the rest with cellulose.
The hybrid foam installation method combines energy efficient spray foam with conventional insulation to create a lower cost alternative to using foam alone.
Let us start by considering the benefits and costs of spray foam insulation vs.
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.
Fiberglass devoured the insulation industry in the 1970s for obvious reasons.
Many insulation companies in our area have begun to sell hybrid insulation systems.
You can get similar results as doing all closed cell foam but with less cost.
Fiberglass insulation and other standard products such as cellulose wool and other mass type insulation.
We launched our system three years ago and there wasn t much conversation.