Montreal • Laval • North & South Shore
P-Traps & 1.5″ Line Clogs: Montreal Homeowner Guide
P-traps protect your home from sewer gas—but in Montreal kitchens, 1.5″ lines and tight trap bends clog fast. Use these safe DIY steps, spot the early signs, and see when a camera or hydro-jet is the best fix.
6–8 min read
Why small-diameter lines clog faster
Kitchen branches are usually 1.5″. Add a tight P-trap bend, cooler pipe walls, and grease/food particles—flow narrows quickly. In Plateau, Rosemont, NDG and older West Island homes, long runs to the street and winter freeze-thaw speed up buildup.
First step: A quick camera inspection shows if it’s grease, scale, a dropped object, or a misaligned joint—so you pick the right tool.
See inside the line before it becomes an emergency.
Safe DIY for a clogged P-trap (without damaging pipes)
✅ What to do
- Place a pan under the trap. Wear gloves.
- Loosen the two slip-nuts by hand (use a towel for grip). Keep the washers safe.
- Remove the U-bend and clean out sludge/food. Rinse outdoors, not in another sink.
- Reassemble with the washers seated correctly; hand-tighten, then a tiny extra turn.
- Run water, check for leaks, then do a hot-water flush (2–3 min).
🚫 What to avoid
- Over-tightening plastic slip-nuts (they crack easily).
- Chemical openers—they’re harsh and don’t remove films.
- Pouring grease down the sink; it re-coats the line.
- Using a long metal snake in thin kitchen branches—it can score fittings.
Early warning signs in Montreal kitchens
- Slow drain that briefly improves with hot water.
- Gurgling after the basin empties—air catching on partial blockage.
- Rancid/greasy odour near the sink or dishwasher.
- Recurring clogs despite DIY cleaning.
Kitchen acting up often? See: Why your kitchen drain keeps backing up and the Ultimate Guide to Unclogging in Montreal.
Grease or biofilm deeper in the line? 360° cleaning beats “poking a hole.”
Maintenance that actually helps 1.5″ lines
- Strainer discipline: Catch scraps; empty to trash daily.
- Hot-water flush: After heavy cooking, run hottest tap 2–3 min.
- Enzyme upkeep: Routine dosing can limit biofilm (not a cure for thick grease).
- Zero-grease rule: Cool–contain–trash. See our grease guide for details.
New homeowner or recurring issues? Book a targeted check: Drain Inspection for Homeowners (Montreal).
When to call a pro
Scope first: A camera inspection confirms whether you need jetting, localized repair, or just a thorough clean.
For established grease: Hydro-jetting scrubs the full circumference, restoring diameter and reducing re-clogs. Cables often only puncture a small channel.
Emergency? If fixtures back up or you smell sewage, go to Emergency Drain Services (Montreal) and avoid running water until help arrives.
Related reads: Kitchen Sink Clogged — Expert Solutions.
Ready when you are. Montreal • Laval • North & South Shore.
FAQ: P-traps & small lines
What size is my kitchen line?
Most Montreal kitchens use 1.5″ branches with a P-trap under the sink. Older homes may vary—scoping confirms.
Is it safe to remove and clean my P-trap?
Yes—if you protect the cabinet, keep washers, and avoid over-tightening. If the trap is corroded or cross-threaded, call a pro.
Do chemical drain openers work on grease?
They’re hard on pipes and usually don’t remove films. Mechanical cleaning or hydro-jetting is more effective.
Why does the clog keep coming back?
There’s often established grease/biofilm downstream or a line defect. A camera inspection finds it.
Who should I contact right now?
For urgent backups, use Emergency Drain Services or Contact.
Written by Flow Pro Drain Inc. — Montreal • Laval • North Shore. Master-plumber supervised. Certified Drain Report™ available.