What Is UFFI?
UFFI is a foam insulation that was mixed on-site and injected into wall cavities, popular in the late 1970s during a period when energy efficiency was a national priority following the 1973 energy crisis. The federal government even offered grants to encourage homeowners to install it. An estimated 100,000 Canadian homes received UFFI before its use was banned under the Hazardous Products Act in December 1980.
Why It Was Banned
UFFI off-gasses formaldehyde during mixing and curing. In properly installed applications, this off-gassing typically lasted only a day or two, but poor installation practices — common given how quickly the industry scaled up — could extend this considerably. Concerns about formaldehyde exposure led to the 1980 ban, following thousands of homeowner complaints of symptoms like eye irritation, headaches, and respiratory discomfort.
The Current Consensus
More than four decades on, the scientific picture has shifted considerably. Multiple studies since the ban have found that homes with UFFI installed decades ago show no higher formaldehyde levels today than homes without it — the off‑gassing process is long since complete. The Canada Mortgage and Housing Corporation (CMHC) has stated homes with older UFFI don't show elevated formaldehyde compared to those without. Today, UFFI is mainly a disclosure and stigma issue rather than an active health hazard. However, if UFFI becomes wet due to water intrusion or prolonged moisture exposure, the foam can break down and lose insulating value, which is the primary concern inspectors watch for today.
What We Look For
- Construction dating to the late 1970s, when UFFI installation was most common
- Signs of foam insulation visible at wall penetrations or during renovations
- Any shrinkage gaps, which are common with UFFI and can reduce its insulating value
What this means for you
If UFFI is confirmed in a home, it generally doesn't need to be removed for health reasons today, though some lenders and insurers still ask about it on disclosure forms out of habit from decades past. The practical impact is usually more about paperwork than risk.
However, if UFFI has become wet due to water intrusion or prolonged moisture exposure, the foam can break down, lose insulating value, and may deteriorate into a crumbly or powdery material. In these cases, professional removal is recommended to prevent further degradation and to restore proper insulation performance.
CMHC Notice: View official guidance