Several building materials that were standard in their day are now known to fail or to worry insurers. If your home has one of them, a renovation is the cheapest time to deal with it, because the walls and ceilings are already open.
Knob-and-Tube Wiring
Common in homes wired before the 1950s. You may see ceramic knobs and tubes in the attic or basement holding separate wires. It has no ground, its insulation degrades with age, and it overheats when covered by insulation. Many insurers will not cover a home with knob-and-tube in service, or only for a limited time. Replacement is done by a licensed electrical contractor under an ESA permit.
Aluminum Branch Wiring
Used in many homes built from the mid-1960s to the late 1970s. The wire itself is not the main problem; the connections are. Aluminum expands and oxidizes differently from copper, so connections at outlets, switches and fixtures can loosen and overheat. A licensed electrician can remediate it with approved connectors and devices or replace it. Insurers commonly ask for an inspection.
Poly-B Plumbing
Polybutylene supply pipe, usually grey, was installed from the late 1970s to the late 1990s. It can become brittle and fail without warning, especially at fittings. Many insurers ask about it, and replacing it with PEX or copper while walls are open is the usual approach.
Kitec Plumbing
Kitec, an orange and blue pipe system with brass fittings, was installed from the mid-1990s to the late 2000s. The fittings can corrode and fail. It is often visible at the water heater and manifold. Replacement is the standard recommendation.
Galvanized and Cast Iron
Older homes may still have galvanized steel supply pipes, which corrode inside and reduce water pressure, and cast-iron drains, which crack and rust over time. Both are worth replacing when a kitchen, bathroom or basement is being renovated.
How to Plan for It
Find out early. Look in the electrical panel, along the basement ceiling and at the water heater, or ask your contractor to check during the quote visit. Then build the replacement into the scope rather than discovering it halfway through the job.
