The supply line is the least glamorous part of any plumbing fixture: a short flexible hose running from the shut-off valve up to the faucet or toilet. It is also the part most likely to let go while you are at work, at the cottage, or asleep. A failed line runs at full household pressure until someone closes a valve, which is a big reason water damage sits among the leading causes of home insurance claims in Canada. Braided supply lines cost a small fraction of what any fixture does, take about ten minutes to swap, and remove one of the most common sources of that damage. That is the cheap flood insurance in the title.
What a braided supply line actually is
Every braided line has two parts doing two jobs. The inner tube, usually a flexible polymer or EPDM rubber, carries the water and provides the seal. The outer braid, woven from stainless steel strands or a tough polymer, holds no water at all. It stops the inner tube from ballooning under pressure and protects it from abrasion and kinks. At each end, a crimped ferrule locks braid and tube to a nut that threads onto the valve and the fixture.
Compare that with what you still find in older Canadian homes: rigid chrome-plated risers that need careful bending, grey plastic tubes that crack with age, and unbraided rubber washing-machine hoses with a reputation for bursting. Braided lines tolerate misalignment, install by hand plus a fraction of a turn, and a well-made one usually outlasts the fixture it feeds.
Stainless braid or polymer braid?
Both are legitimate choices, and either one from a reputable, certified manufacturer is a huge upgrade over an aged plastic tube. The differences show up in specific environments.
| Type | Strengths | Trade-offs | Best fit |
|---|---|---|---|
| Stainless steel braid | Excellent crush and abrasion resistance, tidy look, sold in every common size and length | Can corrode where chlorinated cleaners are stored or cabinets stay damp; frayed strands are sharp | General-purpose choice for faucets, toilets and dishwashers |
| Polymer braid | Will not corrode, lighter, quieter under flow, often more flexible in tight cabinets | Less resistant to crushing; quality varies more between brands | Coastal or humid locations, laundry areas, cabinets that see harsh cleaners |
The exception is exposed plumbing under a pedestal or wall-mount sink, where a decorative supply kit that pairs a finished shut-off with a matching riser, the sort of thing Mountain Plumbing makes, looks far better. Inside a vanity, a plain braided line is the sensible choice.
Getting the size and connection right
Canada is a metric country, but plumbing fittings never got the memo. Supply lines are sold in imperial sizes from Vancouver to Halifax.
- Bathroom and kitchen faucets: typically a 3/8-inch compression nut at the valve and a 1/2-inch female pipe thread at the faucet. Many current faucets from brands such as Kohler, Riobel and Brizo arrive with flexible hoses already attached, so no separate line is needed. Check the box before you buy.
- Toilets: a 3/8-inch compression nut at the valve and a larger 7/8-inch ballcock nut at the tank. Most toilets, including those from TOTO and Kohler, do not include a supply line.
- Washing machines: 3/4-inch hose thread on a heavier braided hose. If yours are still black rubber, replace them now.
Measure from valve outlet to fixture inlet and choose the next length up, so the line runs in a gentle curve. Never pull a line taut or coil it tightly. Both strain the crimp, which is where most failures begin.
Where braided lines fail, and how to avoid it
- Cheap nuts. Zinc or pot-metal nuts crack when tightened or corrode from the inside. Look for solid brass or stainless nuts and a CSA or cUPC mark on the packaging.
- Overtightening and thread tape. The washer inside the nut makes the seal, not brute force or tape. Hand tight plus a quarter turn is the rule, and pipe dope can actually stop the washer from seating.
- Kinks. Every tight bend fatigues the inner tube and frays the braid. Buy a different length instead.
- Corrosion. Bleach stored under the sink releases vapours that attack stainless braid over time. Store it elsewhere or choose polymer braid.
- Water chemistry. Some Canadian municipalities disinfect with chloramine, which ages certain rubber compounds faster. If yours does, favour lines specified as chloramine resistant.
- Old age. Supply lines are consumables. A common rule of thumb is to replace them within about a decade, sooner in hot or humid spots, and always with a new fixture.
The Canadian details that matter
Certification. Look for a CSA or cUPC mark rather than a bare import. The National Plumbing Code sets the framework, but provinces adopt and amend it on their own schedules, and Quebec administers its own code, so your local inspector or licensed plumber is the final word.
Cold climate. A braided line does not freeze any more readily than the pipe feeding it, but it is often the most exposed section of that pipe. Vanities on exterior walls, garage laundry hookups, and unheated cottages in Muskoka, the Laurentians or the Kootenays are where a frozen line splits and floods the room on the first mild day. For seasonal properties, closing the shut-offs and draining the fixtures before winter is the real protection, and quarter-turn ball valves make that a thirty-second job.
Humidity and salt. Coastal homes in British Columbia and Atlantic Canada, and basement bathrooms anywhere, see more cabinet condensation than a dry Prairie house. That is where polymer braid earns its keep.
A ten-minute replacement
- Close the shut-off valve. If it will not turn, or drips when it does, replace the valve at the same time.
- Open the faucet to relieve pressure, then unthread the old line over a towel.
- Clean both sets of threads, confirm the washer is seated in each new nut, then thread both ends on by hand and snug each a quarter turn while holding the valve steady with a second wrench.
- Open the valve slowly, check both ends for weeping, and check again the next day.
- Replace hot and cold together, and never reuse an old line on a new fixture.
Pairing supply lines with a new fixture
Supply lines matter most when you are already under the cabinet. If you are shopping for a new bathroom faucet or kitchen faucet, check the installation sheet to see whether hoses are integrated, and replace old multi-turn shut-offs while you are there. For a new toilet, budget for a new braided line and a quarter-turn stop. Vatero ships fixtures Canada-wide, and our guides hub covers the rest of the installation, from rough-in measurements to choosing a valve.
Frequently asked questions
How often should braided supply lines be replaced?
There is no fixed expiry date. Inspect yearly for rust, bulging or fraying, replace within roughly ten years regardless of appearance, and always fit new lines when a fixture is replaced.
Are stainless steel or polymer braided lines better?
Stainless braid resists crushing and abrasion better and is the default for most installs. Polymer braid cannot rust and is the better pick where cabinets stay damp, where chlorinated cleaners are stored, or in coastal air. Either beats an aged plastic tube.
Can I reuse a supply line when I replace a faucet?
You can, but you should not. The washers have taken a set, the crimp has seen years of pressure cycles, and a new line costs very little compared with the damage a failed one causes.
Do I need thread tape on a braided supply line?
No. Both ends seal with a washer or a compression fitting, not the threads, and tape or pipe dope can keep the washer from seating. Hand tight plus a quarter turn is all it takes.
