Open-cell foam insulation in Davenport IA - a room under the roof that stays comfortable

It's usually worth it when your ductwork runs through the attic or you want the space under the roof to be part of the house, and usually not when the attic is just a floor you never walk on. Foam costs more because it seals air while it insulates, but in a plain attic, attic air sealing around the lights, pipes and hatch plus a top-up of blown-in insulation usually gets you more for your money. I'll tell you which one your house calls for when I come out.

Open cell is usually the pick under a dry roof deck, and closed cell is the pick when moisture is the worry, because closed cell at normal thickness all but stops water vapor and open cell doesn't. Both block air well, and closed cell is also denser, stiffer and packs more insulating value into each inch. You can read more on our closed-cell foam insulation page.

Yes, one building guide rates open-cell foam acceptable in cold climates when it's sprayed straight onto a sloped roof deck. That covers sealed attics with no vents and cathedral ceilings, the finished rooms shaped by the roof slope. It puts the full insulation at the roof and stops outside air from leaking in, so it fits a house where you want the attic inside or a room under the roof.

EPA guidance says everyone should be out during the spraying and stay out until the foam has finished curing and the house has been aired out and cleaned. Some foam makers recommend 24 hours after professional high-pressure foam before people come back, though that varies, so EPA says to get the time for the exact product from its maker or supplier. EPA also tells installers to shut down and seal off the heating and cooling openings in the work area, then unseal and restart the system only after the foam has cured and the space is aired out and clean.

Davenport says building and specialty work generally has to be done by a licensed and bonded contractor. If you hold legal title to a single-family home, the city lets you do remodeling yourself without a contractor license, though not mechanical, electrical or plumbing work, and you'd take out any permits with the city yourself. Iowa also requires anyone earning at least $2,000 a year from construction work to register with the state's Department of Inspections, Appeals, and Licensing, while people working only on their own property don't have to.

Ask exactly where the foam will go, so the plan covers the spaces you want insulated and nothing else. EPA also suggests asking what time of year and what weather suit the job, since curing varies, and what happens at each stage, including how the crew closes off and airs out the work area. Call (563) 265-6737 and I'll walk you through all of it at your house.