# What are the red flags in older Edmonton homes? By Banish Angural · Published October 16, 2026 · Updated October 18, 2026 > Common red flags in older Edmonton homes include Poly-B plumbing, knob-and-tube or aluminum wiring, vermiculite insulation that may contain asbestos, galvanized steel pipes, old oil tanks, foundation cracks with poor grading, ungrounded outlets and aging furnaces. An inspection can spot visible signs; a plumber, electrician, asbestos professional or other specialist confirms and prices the fix. Older homes in Edmonton’s mature neighbourhoods often have materials and systems that were standard when they were built but are viewed differently today. Finding one is not a reason to walk away. It is a reason to understand it, price it and check how it affects insurance before your conditions come off. Below are the items insurers, lenders and inspectors ask about most, what each one looks like, and who follows up. A home inspection is visual, so it can point to likely signs but cannot confirm what is inside walls or test materials. ## Why do insurers and lenders care about these items? Insurers price risk, and some older materials are linked to water damage or fire. The [Financial Consumer Agency of Canada](https://www.canada.ca/en/financial-consumer-agency/services/insurance/home.html) notes that insurers consider a home’s characteristics, such as its materials and age. If you have a mortgage, the policy usually names your lender as loss payee, so a home that is hard to insure can also complicate financing. Call an insurance broker early in your condition period with what the inspection found. That conversation is often what turns a red flag into a clear decision. ## What does Poly-B plumbing look like? Poly-B (polybutylene) is a flexible plastic supply pipe, usually grey but sometimes blue, white or red, often with copper or brass fittings. [Westland Insurance](https://www.westlandinsurance.ca/news/has-your-broker-asked-if-you-have-polybutylene-poly-b-plumbing/) says it was installed in Canada from about 1978 to 1997 and may be stamped "PB". It notes that insurers may respond with a surcharge, a deadline to replace, or declined water damage coverage. An inspector looks for it where pipes are exposed, such as at the water heater, under sinks and in an unfinished basement. **Follow-up:** a plumber to confirm and quote replacement. ## What is knob-and-tube wiring? Knob-and-tube is early wiring with single insulated conductors held on porcelain knobs and passed through framing in porcelain tubes. [Canadian Underwriter](https://canadianunderwriter.ca/2024/02/21/managing-insurer-concerns-about-knob-and-tube-wiring/) describes it as a standard method before 1950 and says insurers are generally reluctant to cover pre-1950 homes that still have it. It may be visible in an unfinished basement or attic, though much of it is hidden in walls. **Follow-up:** an electrician to assess how much is still live and what insurers in your case will accept. ## What does vermiculite insulation look like? Vermiculite is loose-fill insulation that looks like small, light pebbles, silver-gold to grey-brown. The [Canadian Centre for Occupational Health and Safety](https://www.ccohs.ca/oshanswers/diseases/vermiculite.html) explains that Zonolite attic insulation sold in Canada came from a mine in Libby, Montana, that was contaminated with asbestos, and that not all vermiculite sold in Canada before 1990 contains asbestos. [Health Canada](https://www.canada.ca/en/health-canada/services/air-quality/indoor-air-contaminants/health-risks-asbestos.html) advises not to disturb vermiculite insulation or remove it yourself, and to hire professionals trained to handle asbestos if you plan to renovate. An inspector can note material that looks like vermiculite in the attic but will not sample or test it. **Follow-up:** a qualified asbestos professional to sample it and send it to an accredited lab. ## Are galvanized steel pipes a problem? Galvanized supply pipe is grey, rigid steel with threaded joints. [Square One Insurance](https://www.squareone.ca/?p=22940) describes it as common in homes built before 1950, says it corrodes from the inside where you cannot see it, and notes that some insurers require replacement or limit water damage coverage. Low water pressure or rusty water can be signs. In Edmonton, grey pipe at the water meter may also be lead. [EPCOR](https://www.epcor.com/ca/en/ab/edmonton/safety/water-quality/lead-drinking-water.html) says homes built before 1960 are the main concern for lead service lines and that a water test is the only way to be sure. [Health Canada](https://www.canada.ca/en/health-canada/services/environmental-workplace-health/reports-publications/water-quality/water-talk-minimizing-exposure-lead-drinking-water-distribution-systems.html) calls lead service lines the most significant likely source of lead in drinking water. **Follow-up:** a plumber for the pipes, and EPCOR for lead testing. ## What about aluminum wiring? Aluminum branch wiring shows up in some homes from the mid-1960s to late 1970s. The [Electrical Safety Authority](https://www.esasafe.com/home-renovation-buying-and-selling/aluminum-wiring/) in Ontario says it is safe when connections are made properly with devices approved for aluminum, and that some insurers want an inspection before they will cover the home. Its guidance is written for Ontario, but the insurance question applies here too. An inspector may see "AL" or "ALUMINUM" printed on cable sheathing in the panel or basement. **Follow-up:** an electrician experienced with aluminum wiring to check connections. ## What if there is an old oil tank? Signs of a past oil tank include a fill or vent pipe on an exterior wall or capped lines in the basement. An inspector will note these but cannot confirm whether a tank is buried. In Edmonton, the [City’s fuel tank permits page](https://www.edmonton.ca/programs_services/fire_rescue/fuel-tank-permits) says removing a storage tank requires a permit and a petroleum contractor approved by the Safety Codes Council. **Follow-up:** a qualified contractor to locate the tank and advise on removal, and your lawyer about what the seller should provide. ## Should I worry about foundation cracks and grading? Many cracks are minor. What matters is the width, the direction, whether walls have moved, and whether water is getting in. Central Edmonton sits on [glacial and glacial lake deposits](https://ags.aer.ca/node/18877), and the [Geo-Institute](https://geoinstitute.org/sites/default/files/inline-files/LivingWithShrinkSwellSoils_updated.pdf) explains that clay-rich soils can swell when wet and shrink as they dry, which can move foundations. Grading makes a big difference. The [City of Edmonton](https://www.edmonton.ca/residential_neighbourhoods/lot_grading/lot-grading-problems) says grading should direct water away from the house and that settlement near foundation walls can develop slowly over years. An inspector checks the visible foundation, grading and downspouts. **Follow-up:** a structural engineer or foundation specialist for significant cracks or movement. ## Why do ungrounded outlets matter? Older homes often have two-prong outlets, or three-prong outlets added later without a ground wire. An inspector checks a sample of outlets with a plug-in tester and reports ones that are not grounded or are wired with reversed polarity. Grounding gives a fault a safe path, and some devices need it. **Follow-up:** an electrician to explain options under the Canadian Electrical Code. ## When is an old furnace a concern? Age alone is not a defect, but older furnaces deserve a careful look at the heat exchanger area that is visible, the venting and the controls. [Health Canada](https://www.canada.ca/en/health-canada/services/air-quality/pollutants/carbon-monoxide/preventing-exposure.html) recommends having fuel-burning appliances inspected by a professional at least once a year, watching for corroded or disconnected venting, and installing at least one carbon monoxide alarm. **Follow-up:** a licensed gas fitter or HVAC technician for a full service and safety check. ## Who follows up on each red flag? - **Poly-B or galvanized pipe:** licensed plumber. - **Possible lead service line:** EPCOR water test, then a plumber. - **Knob-and-tube, aluminum wiring or ungrounded outlets:** licensed electrician. - **Vermiculite:** qualified asbestos professional and an accredited lab. - **Oil tank signs:** contractor who locates and removes tanks. - **Foundation cracks or movement:** structural engineer or foundation specialist. - **Old furnace:** licensed gas fitter or HVAC technician. - **Any of the above:** your insurance broker, early. For a home in a mature [Edmonton](https://edmontonhomeinspector.com/service-areas/edmonton) neighbourhood or in older parts of [Fort Saskatchewan](https://edmontonhomeinspector.com/service-areas/fort-saskatchewan) or [St. Albert](https://edmontonhomeinspector.com/service-areas/st-albert), a [pre-purchase inspection](https://edmontonhomeinspector.com/services/pre-purchase-home-inspection) gives you a list to take to these specialists. Selling an older home? A [pre-listing inspection](https://edmontonhomeinspector.com/services/pre-listing-home-inspection) lets you deal with these items first. ## Sources - [Has your broker asked if you have Polybutylene (Poly-B) plumbing?](https://www.westlandinsurance.ca/news/has-your-broker-asked-if-you-have-polybutylene-poly-b-plumbing/), Westland Insurance - [Managing insurer concerns about knob-and-tube wiring](https://canadianunderwriter.ca/2024/02/21/managing-insurer-concerns-about-knob-and-tube-wiring/), Canadian Underwriter - [Vermiculite Insulation Containing Asbestos](https://www.ccohs.ca/oshanswers/diseases/vermiculite.html), Canadian Centre for Occupational Health and Safety - [Asbestos and your health](https://www.canada.ca/en/health-canada/services/air-quality/indoor-air-contaminants/health-risks-asbestos.html), Health Canada - [Galvanized steel plumbing](https://www.squareone.ca/?p=22940), Square One Insurance - [Lead in drinking water](https://www.epcor.com/ca/en/ab/edmonton/safety/water-quality/lead-drinking-water.html), EPCOR - [Water Talk: Lead in drinking water](https://www.canada.ca/en/health-canada/services/environmental-workplace-health/reports-publications/water-quality/water-talk-minimizing-exposure-lead-drinking-water-distribution-systems.html), Health Canada - [Aluminum wiring](https://www.esasafe.com/home-renovation-buying-and-selling/aluminum-wiring/), Electrical Safety Authority (Ontario) - [Fuel tank permits](https://www.edmonton.ca/programs_services/fire_rescue/fuel-tank-permits), City of Edmonton - [Geology of the City of Edmonton Part 1: Central Edmonton](https://ags.aer.ca/node/18877), Alberta Geological Survey - [Living with Shrink-Swell Soils](https://geoinstitute.org/sites/default/files/inline-files/LivingWithShrinkSwellSoils_updated.pdf), Geo-Institute of ASCE - [Lot grading problems](https://www.edmonton.ca/residential_neighbourhoods/lot_grading/lot-grading-problems), City of Edmonton - [Carbon monoxide: Preventing exposure](https://www.canada.ca/en/health-canada/services/air-quality/pollutants/carbon-monoxide/preventing-exposure.html), Health Canada - [Home insurance](https://www.canada.ca/en/financial-consumer-agency/services/insurance/home.html), Financial Consumer Agency of Canada ## Questions readers ask ### Can a home inspector test for asbestos in vermiculite? No. An inspector can note insulation that looks like vermiculite, but confirming asbestos takes a sample taken by a qualified professional and tested at an accredited lab. ### Will Poly-B stop me from getting home insurance? It depends on the insurer. Some add a surcharge, set a deadline to replace it, or limit water damage coverage. Ask a broker before your conditions come off. ### How can I tell if my Edmonton home has a lead service line? Homes built before 1960 are the main concern. EPCOR says the pipe colour gives clues but a water test is the only way to be sure.