People are removing spray foam insulation primarily due to hidden moisture issues that cause timber rot, difficulties in securing mortgages or selling a property, and lingering health risks from toxic off-gassing.
Potential problems with spray foam insulation
reduce air circulation and ventilation within a roof space. lead to dampness and condensation on the underside of a roof because it forms an air barrier and stops moisture from escaping. place timber-framed roofs at risk of decay.
On January 1, 2025, a complete nationwide ban on the manufacture of HFC closed-cell SPF systems will take effect. HFC foams manufactured before January 1, 2025 can be sold and applied until January 1, 2028. With product shelf life a major consideration, contractors should plan their HFC foam inventories accordingly.
Because spray foam can trap moisture, hide the condition of the roof, make it difficult for surveyors to inspect, which means risks like timber decay, dry rot, and not forgetting increased fire risk. If you've got it or you're buying a property that does, this is something you need to know upfront.
Spray foam isn't thick enough. Spray foam installers missed some of the air leakage sites. Spray foam installers didn't understand the building envelope and sprayed either too little or too much. Spray foam contracts and pulls away from framing.
The chemical aspect of spray foam makes it very hard for standard insurance companies to provide coverage. Most standard lines insurance carriers want to write the risks with no liability not spray foam contractors that manufacture plastic every day in the field.
Yes, mice can easily chew through foam insulation. Because mice have strong, continuously growing teeth, they will chew through soft materials like foam to create tunnels, sharpen their teeth, or gain access to a warm space.
The healthiest, non-toxic insulation for your home is natural sheep's wool or hemp insulation. These materials contain no chemical binders or formaldehyde, actively regulate indoor humidity to prevent mold, and do not off-gas.
The cost to insulate a new build with spray foam typically ranges from $14,100 to $30,500 for an average 2,000 to 2,500 sq. ft.
Spray foam isn't banned by law, but the mortgage and insurance industries have effectively banned it through lending and coverage restrictions. For practical purposes, spray foam is unusable in UK residential properties because it destroys property value and mortgageability. Don't install it.
Spray foam insulation is designed to be a permanent, "set it and forget it" solution. When properly installed, it can last between 80 to 100 years. It does not sag or settle over time, maintaining its insulating power for a lifetime.
Closed cell spray foam is rigid once set. It is a better thermal insulator and was previously sold to stabilise failing roofs. But if it has been used inappropriately or installed poorly, it might put stress on timbers, restrict air circulation and put them at risk of decaying.
One type is packaging and food service containers made from paper or fber. These products are made from virgin paper, paper with recycled content, or plant fbers such as bagasse, bamboo, wood pulp, and wheat straw. Another packaging option is products made from compostable plastics.
Spray foam insulation (SPF) poses significant health risks primarily during installation, driven by isocyanates and Volatile Organic Compounds (VOCs). Inhaling these vapors can trigger severe asthma, respiratory irritation, and lifelong chemical sensitization. However, once fully cured, the material is generally considered inert and safe.
Direct contact with fiberglass or breathing airborne dust containing fiberglass may irritate the skin, eyes, nose, and throat. The symptoms of irritation are often nonspecific, temporary, and may include itching, coughing, or wheezing.
What time of year is Insulation cheapest?
Spray foam attic insulation is highly effective for superior air sealing and energy efficiency, often saving 15% to 50% on heating and cooling bills. However, it costs up to 3 to 4 times more than traditional blown-in insulation and can hide roof leaks or trap moisture if improperly installed.
The cost to spray foam insulate garage with a 20' x 20' dimension is $2,000 - $6,000. Fiberglass and blown-in insulation are cheaper options for insulating a 2-car garage. There is also an additional labor cost between $2,200 to $7,000.
The Environmental Protection Agency banned spray-on asbestos insulation in 1973, certain types of pipe and block insulation in 1975 and new asbestos insulation products in 1989. In 2024, the EPA banned most uses of chrysotile asbestos products, including imports.
Yes, mice can chew through rockwool. While the dense, spun-stone fibers are not edible and are much harder to burrow into than soft fiberglass, a determined mouse will chew through rockwool to build nests or create pathways through walls.
The Five Most Efficient Insulation Materials
The Amish control mice through non-chemical, self-sustaining methods, relying on active trapping, natural scent repellents, and structural exclusion. Rather than using commercial poisons, they focus on physical barriers and natural predators to keep rodent populations in check.
Rats are a primary food source for a wide variety of animals. Their most significant natural and artificial predators include:
There is no single "chew-proof" insulation that will unilaterally stop a highly motivated rodent, but combining borate-treated dense-pack cellulose or mineral wool with physical exclusion materials creates an impassable barrier. Traditional fiberglass is highly susceptible to nesting.