Frequently asked questions

It depends on where. Two inches of closed-cell foam at the rim joist seals and insulates the band. Two to three inches on a basement or crawl space wall reaches the range of Iowa's R-15 to R-19 code benchmark for those walls. In an open attic, foam is used mainly to air seal the floor, with blown insulation on top to reach R-49. Roof decks and pole barns are scoped by how the space is used. The written scope lists a thickness for each area.

In an old Des Moines house the biggest losses are air leaks through the attic floor and the rim joist, and those cannot be fixed with blown insulation alone. Foam is the efficient way to close big irregular openings like balloon-framed wall tops and the rim. Once the leaks are closed, blown insulation is often the most economical way to add depth. Most old-house scopes use both.

Foam on the underside of the roof deck, which converts the attic to an unvented assembly, is something some shingle manufacturers address in their warranty terms. Foam used to air seal the attic floor with a vented attic above it does not touch the roof. If a roof-deck application is on the table, we will tell you to check your shingle warranty before deciding.

Not over live knob-and-tube. Insulation of any kind covering energized knob-and-tube is a fire hazard, and it is not permitted. An electrician must inspect the wiring and either de-energize it or confirm it is safe to cover. We will point it out if we see it and pause that area until it is resolved.

Cured foam is not a food source and does not attract insects or rodents. It does close many of the gaps mice use to get into a rim joist or attic, which is a side benefit. It is not a pest control product, and a determined animal can chew through it, so entry points should still be closed with metal or masonry where animals are a known problem.

A blower door depressurizes the house and measures how much air leaks in, reported as air changes per hour at 50 pascals. Iowa's energy code requires 4 ACH50 or better for new one- and two-family homes. On a retrofit, a blower door test before and after air sealing shows how much the leakage dropped. It is not required for existing homes, and we do not promise a specific number, but it is the honest way to measure air sealing work.

For most Des Moines houses with an unfinished, accessible attic, the floor: seal it, insulate it, keep the attic vented and cold. The roof deck is the answer when the attic is finished living space, a cathedral ceiling, or too shallow to insulate on the floor. It is a different design with its own moisture rules, and we will explain the trade-offs before you choose it.

Yes, with attention to combustion safety. Tightening a house changes the pressure balance that an atmospherically vented appliance depends on to draft properly. The scope will note that combustion appliance zone testing should be done after the air sealing, and if the results call for it, that a sealed-combustion appliance or added combustion air may be needed.

Closed-cell foam is a vapor retarder and is not affected by humidity, which is why it is used against concrete and steel. In a sealed crawl space it stops the summer condensation that used to form on cold pipes and ducts. Open-cell foam is vapor-open and is kept out of below-grade and high-humidity locations for that reason.

Yes: steel and post-frame commercial shops, warehouses, small industrial space and agricultural buildings across the metro, plus rim joists, roof decks and foundation walls on small commercial and multi-family buildings. Larger commercial roofing systems are a different trade. Tell us what the building is and we will say whether it is a fit.

Spray foam is sensitive to substrate and ambient temperature. The crew heats the material, checks the surface temperature and, in an attic or crawl, may use temporary heat to bring the substrate into the manufacturer's range. If conditions are outside what the product allows, the job is rescheduled rather than sprayed badly.

Insulation-only retrofits often do not require a permit, but basement finishing, structural work and some roof-deck applications do, and requirements differ between Des Moines, the suburbs and unincorporated Polk, Dallas and Warren counties. Local jurisdictions in Iowa may also adopt a newer energy code than the state's. We will tell you what applies to your project and coordinate with the building department if a permit is needed.