Poly B is the common name for polybutylene water supply pipe, installed in Canadian homes from roughly 1985 to 1997. Calgary has an unusual amount of it, because the city built heavily through exactly that window.
This page is the short version of the whole site: what the pipe is, the two ways out of it, what the work costs, and why an insurance renewal letter is what pushes most Calgary homeowners into dealing with it.
Start here
- Poly B ReplacementWhat a whole-home repipe involves, what replaces the pipe, and what is and is not included.
- Poly B RepairWhen a targeted repair is legitimate, when it is wasted money, and how long one lasts.
- Replacement CostPublished Calgary ranges with sources, what moves the number, and what a quote must itemise.
- Poly B and InsuranceSurcharge, non-renewal or refusal — and the proof an insurer wants once the pipe is gone.
What Poly B is, and how to identify it
Poly B is a flexible plastic supply pipe, most often grey, sometimes white, cream or black. In a Calgary house it runs from the water meter through the floor joists to the fixtures, usually in 1/2 inch and 3/4 inch. The giveaway is the stamp on the pipe wall: PB2110. If a pipe reads PB2110, it is polybutylene.
It is not the pipe wall that usually fails. It is the connections. Original installations used acetal plastic insert fittings held with crimped metal rings, and those fittings are the documented weak point. Chlorine and chloramine in treated municipal water also attack the inside surface of the pipe over decades, which makes it brittle and leaves micro-fractures that show up as pinhole leaks.
- Grey, white, cream or black flexible plastic, not rigid like copper
- Stamped PB2110 along the length
- Crimp rings at every fitting, often with a plastic insert underneath
- Most visible at the water heater, under sinks, and in an unfinished basement ceiling
Why Calgary has so much of it
Roughly 28.8 percent of Calgary's housing stock was built before 1991, which puts an enormous number of homes inside the Poly B installation window. Not every home from that period has it, and some have already been repiped, but the overlap between Calgary's late-1980s and early-1990s building boom and the years Poly B was standard is why this is a city-wide issue here and a curiosity somewhere else.
The concentration is not even. Communities that filled in through the late 1980s and early 1990s carry the highest share, while both older inner-city stock and anything built after about 1998 are largely clear.
The two paths: repair or replace
Almost every Poly B decision comes down to one of two paths. Most of what is published on the subject argues for the second one without ever making the case for the first, which is why the comparison below exists.
| Targeted repair | Whole-home replacement | |
|---|---|---|
| What happens | The failed section, joint or fitting is cut out and replaced | All Poly B supply pipe in the house is abandoned and re-run in new material |
| Typical trigger | A single leak, in an accessible spot, in a house with no leak history | Repeated leaks, an insurance condition, a renovation, or a sale |
| Relative cost | A small fraction of a repipe | The full published Calgary range |
| What it fixes | That failure | The whole system, including the failures that have not happened yet |
| What it does not fix | The rest of the original fittings, which are the same age | Nothing left to fix on the supply side |
| Effect on insurance | Usually none. Insurers are asking about the material, not the leak | The thing insurers are actually asking for |
- The repair path, in detail, including when it is the right call →
- What a whole-home replacement actually involves →
What to look for in a Poly B company
The same questions separate a competent Poly B contractor from an underspecified quote, whether the job is one fitting or the whole house. None of them are about price.
- Is repiping a core line of work for the company, or something it does occasionally between other jobs
- How many whole-home repiping jobs has it completed in Calgary in the last year
- Can it name the pipe, the fitting system and the manufacturer it intends to use, and say why
- Is the trade licence current, and does the quote include pulling the City of Calgary permit and passing inspection
- Who does the drywall afterwards, the repiping crew, a separate drywall trade, or nobody
- Will it put the scope in writing at the level of detail the cost page lists, or only a total
- Will the invoice afterwards state explicitly that all polybutylene was removed, which is what an insurer needs to see
A Poly B replacement specialist will answer all seven without hesitating. A repipe specialist who will not put the fitting system in writing is quoting a different job from the one being compared against it.
What it costs
Published Calgary figures for a whole-home repipe disagree with each other by more than the price of a car, and almost none of them say what is included. The cost page sets the published ranges side by side with their sources, explains why they diverge, and lists what a written quote has to itemise before two quotes can honestly be compared.
What insurance does about it
For a lot of Calgary homeowners the pipe was never the problem. The renewal letter was. Insurers have moved from ignoring Poly B, to surcharging it, to limiting water damage coverage, to declining to renew. The insurance page covers the difference between those outcomes, what documentation an insurer typically wants once the pipe is gone, and where a mortgage lender fits in.
Who this site is for
Someone who has just found grey pipe in the utility room and wants to know how worried to be. Someone holding a renewal notice that mentions polybutylene. Someone with one quote in hand and no way to judge whether it is reasonable. Someone deciding whether a house with Poly B is still worth buying.
It is written to answer those questions plainly, including the times the honest answer is that nothing needs to be done this year.