Frequently asked questions

During application and for a period afterward, yes, at least from the part of the house being sprayed. Two-component foam releases vapors while it reacts and cures, and the work area is ventilated during and after. How long occupants stay out depends on the product, the ventilation and the size of the job, and we give you the manufacturer's written re-entry guidance for the product used rather than a rule of thumb. Most attic and crawl space jobs allow the rest of the house to be occupied with the work zone isolated; whole-house or roof-deck jobs often mean a night away. We tell you which at the assessment.

By the surface area and the depth of foam, adjusted for the product, access and prep. A crawl space is priced by the wall and rim joist area at a specified depth of closed-cell; a roof deck by the square footage at a specified depth of open- or closed-cell; removal and vapor barrier are line items of their own. You get all of that in a written scope so you can compare it directly against another bid. We do not publish prices on this site because no two houses need the same scope.

Some shingle manufacturers have historically limited or excluded coverage for roofs over unvented attics, and others have not. It depends on the manufacturer and the specific warranty. If you have a roof still under warranty, we suggest checking the terms before deciding between roof-deck foam and a sealed, insulated attic floor, and we will scope both so the decision is yours.

It usually ends up oversized, which sounds like a good thing and is not. A tight, well-insulated house needs less heating and cooling, and an oversized air conditioner cools the air so fast that it shuts off before it has removed much humidity, leaving the house cool and clammy. When you next replace equipment, the new system should be sized to the improved house. In the meantime, keeping the fan on auto rather than on, and using a dehumidifier if needed, manages it. Sealing the house also changes ventilation needs, which we cover at the assessment.

Fully cured polyurethane foam is a stable, inert plastic, the same family of material as the foam in a couch cushion or a refrigerator wall. The health precautions apply during and shortly after application, when the components are reacting, which is why installers wear supplied-air respirators and the area is ventilated and kept clear. Problems that have made the news typically trace to installation errors: wrong ratio, wrong temperature, lifts too thick, or occupants returning too soon. Those are process controls, and they are the reason the process matters more than the brand.

Foam plastic insulation is combustible, so the building codes require that it be separated from the living space by a material that slows fire from reaching it, most commonly half-inch gypsum board. That is a thermal barrier. In attics and crawl spaces that are used only for service access, the code allows a lesser ignition barrier or a foam product that has been tested and approved for exposed use in that location, or an intumescent coating sprayed over the foam. If your foam will be exposed in an attic, crawl space, garage or shop, one of those is required, and we put it in the scope rather than leave it to be discovered at inspection.

Foam is not a food source for termites or rodents, but it is also not a barrier to them, and termites can tunnel through it to reach wood. Foam on a foundation wall can also hide termite mud tubes from view. That is why we keep the foam and vapor barrier a few inches below the top of the foundation wall in a crawl space, leaving an inspection strip where a pest control professional can see the sill. If you have a termite bond, tell your pest company about the encapsulation so they can keep inspecting properly.

It can, but not easily. Cured foam is bonded to whatever it was sprayed on and has to be cut, scraped or ground off, which is slow and messy. That permanence is a reason to be deliberate about where it goes. It is also why we will not spray over a roof leak, wet framing or anything else that would need to be reached later, and why we photograph and note the location of wiring, junction boxes and plumbing before foam covers them.

It depends on the house, and the assessment is where we settle it. In general, if you have HVAC equipment in the attic and hot upstairs rooms, the attic is the bigger win. If you have damp floors, a musty smell and ductwork in the crawl space, the crawl space is. In a Chattanooga-style ranch with the air handler in the crawl space and no second floor, the crawl space almost always comes first. We scope both so you can see the comparison.

On an attic floor, blown material is the lower-cost way to add R-value, and once the attic floor is properly air-sealed it performs well. Where blown material falls short is that it cannot air-seal by itself and it does nothing for ductwork and equipment in the attic above it. Spray foam on the roof deck costs more per square foot but solves both problems. Our usual recommendation is foam for the air sealing and any roof-deck work, and blown material where the job is simply adding depth to a well-sealed attic floor.

We provide the documentation the program asks for on the contractor's side: the scope, product information, depth and square footage, and before-and-after photographs. Eligibility, the application itself and the payment run through EPB and TVA under their rules, which include using a contractor listed in the Quality Contractor Network for existing homes. We are straightforward about our status with the program and about what you can and cannot expect from it, and we will not tell you a rebate is coming until the program says so.

Not around active knob-and-tube. Knob-and-tube wiring dissipates heat into open air, and burying it in any insulation, foam or otherwise, is a fire hazard and a code violation. If we find it, the wiring has to be replaced or de-energized by an electrician before insulation goes in. Aluminum branch wiring from the 1960s and 1970s is a different issue that does not prohibit insulation, but we note it when we see it so you can have it evaluated.