Closed -cell spray foam and fiberglass/Cellulose can be used together to maximize performance and minimize cost.
A hybrid insulation method involves a combination of different types of insulation, most commonly spray foam and fiberglass or cellulose. This cost-effective method, referred to as “flash and batt,” combines the high-performance capabilities of spray foam with the economics of fiberglass or cellulose, creating a less costly yet still high-performing building enclosure.
Contrary to using fiberglass on its own, the closed cell foam layer offers a moisture barrier (eliminating rodents, mold, etc.) and the less expensive fiberglass is then added to achieve the desired R-value.