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We deliberately do not publish brand warranty terms here.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.

How to choose

Ask for the product data sheet

It states R-value per inch, coverage, and installation requirements. It is the document that tells you whether the install matches the spec.

Get warranty terms in writing for the exact product

Do not rely on anything a salesperson describes verbally or that you read on a third-party site, including this one.

Separate manufacturer warranty from workmanship warranty

The material warranty covers the material. Bad installation is a workmanship issue, and that only holds as long as the contractor is in business.

For spray foam, record the system and lot

Name of the manufacturer, product line, and batch documentation. This is your only leverage if a curing or odor problem shows up.

Do not pay a premium for a brand name in an open attic

Loose-fill to a specified R-value is a commodity. Buy on installed price and crew quality.