What is UFFI insulation and why can it cause mortgage or insurance problems when buying an older Ontario home?

UFFI stands for urea-formaldehyde foam insulation, a product injected into wall cavities that was popular in Canada in the late 1970s before health concerns led to it being banned from use in buildings. Some older Ontario homes, particularly those insulated or renovated in that era, may still contain it, and its presence has become a standard question on real estate disclosure forms and lender and insurer checklists ever since.

The practical issue isn't necessarily that UFFI is dangerous once properly installed and undisturbed, but that some lenders and insurers remain cautious about it, and a home with known or suspected UFFI can face extra scrutiny, additional inspection requirements, or in some cases financing or coverage difficulty. Because a seller's actual knowledge of UFFI in the home is something they generally must disclose if it's a known condition, buyers of homes from that era should ask directly, review any standard disclosure statement carefully, and consider a specific inspection if the age and renovation history of the home leave real uncertainty. Resolving the question early avoids surprises when arranging a mortgage or insurance later in the transaction.