Insulation brands

The major North American residential insulation manufacturers include Owens Corning, Johns Manville, Knauf and CertainTeed on the fiberglass and mineral wool side, and Demilec, now part of Huntsman Building Solutions, on the spray polyurethane foam side. All publish product data sheets with R-value per inch and installation requirements. Read the data sheet, not the brochure.

We deliberately do not publish brand warranty terms here. Warranty language changes, differs by product line, and often depends on installation by a certified contractor. Get the specific warranty document for the specific product going into your house, in writing, before the job - and check whether it is a manufacturer warranty, a contractor workmanship warranty, or both. Those are different things and only one of them survives the contractor going out of business.

For spray foam, the manufacturer relationship is more meaningful. Ask which system is being sprayed, whether the crew holds current training or certification from that manufacturer, and what the manufacturer's published re-occupancy period is. Keep the product name and lot documentation. If an odor or curing problem appears later, that paperwork is the difference between a manufacturer investigation and a shrug.

The thing brand cannot fix: gaps, compression, missed corners, buried soffit vents and thin coverage in the far reaches of an attic. A premium product installed carelessly performs worse than a budget product installed well. Spend your scrutiny on the crew.