- Difficulty
- Easy
- Time
- 20 to 45 minutes
- Parts
- $0 – $20
- To hire out
- $150 – $450
Most kitchen and bathroom blockages sit in the P-trap, the U-bend directly under the sink, and clear in half an hour with a bucket and a wrench. No chemicals, no specialist tools.
The important part is not the unblocking. It is working out whether the problem is that one sink or the drain system as a whole, because those need very different responses and one of them is not a DIY job at all.
How to tell this is your problem
- Water pools and drains away slowly, or not at all
- A gurgle from the drain when water runs elsewhere
- A smell coming back up the plughole
- The blockage returns within days of clearing it
Should you do this yourself?
Yes, if it is one fixture. Removing a P-trap is four hand-tight fittings and a bucket. Where it stops being DIY is when more than one drain is affected, which points at the branch or main line rather than the trap.
Stop and call someone if
- More than one fixture is slow, or a toilet bubbles when the sink drains. That is the main line, and a plunger will not reach it.
- Sewage is backing up into a tub or floor drain. Stop using water in the house and call someone - that can flood a basement quickly.
- Someone has already poured chemical drain cleaner in. It is still down there, it is caustic, and opening the trap will put it on your hands.
What you need
Tools
- Bucket
Goes under the trap before anything is loosened. It will be full of unpleasant water.
- Channel-lock pliers
Only if the slip nuts are too tight by hand. Wrap the nut in a cloth so the teeth do not chew the plastic.
- Drain snake or auger
A cheap 6-foot hand auger reaches past the trap into the branch. Worth owning if you have older pipes.
- Rubber gloves
Non-negotiable if there is any chance chemical cleaner has been used.
Materials
- Replacement slip washers
A dollar or two. Old ones often refuse to reseal once disturbed, and having them saves a second trip.
Step by step
- 1
Check whether it is one drain or several
Run water in every sink, the bath, and flush a toilet. If only one fixture is slow, the problem is local and this guide applies. If several are, or a toilet gurgles when the sink drains, stop here and call a plumber - the blockage is downstream of anything you can reach.
- 2
Clear the visible bits first
Remove and clean the pop-up stopper in a bathroom sink, or the strainer basket in a kitchen. A surprising share of blockages are hair and soap sitting an inch below the plughole, and never needed the trap opening at all.
- 3
Try a plunger properly
Block the overflow hole with a damp cloth first, or you are just pushing air around. Fill the basin an inch deep so the plunger seals, then push and pull firmly a dozen times. Pulling matters as much as pushing.
- 4
Open the P-trap
Bucket underneath. Loosen the two slip nuts either side of the U-bend, usually by hand. Lower it into the bucket and clear it out. This is where most kitchen blockages live - congealed fat and food, not hair.
- 5
Snake the branch if the trap was clear
If the trap came out clean, the blockage is further along. Feed the auger into the pipe going into the wall, turning as you push. Resistance that gives way with a crunch is usually the clog; resistance that will not move at all may be a joint or a collapsed pipe, which is not yours to fix.
- 6
Reassemble and test
Fit new washers if the old ones look flattened. Hand-tighten only. Run hot water for a full minute and watch every joint - a slow drip under a cabinet can rot the base before anyone notices.
Mistakes that cost money
- Reaching for chemical drain cleaner. It often fails on grease, damages older pipes, and makes the manual fix hazardous for whoever opens the trap afterwards.
- Over-tightening slip nuts. They seal on a tapered washer; cranking them cracks the plastic and creates a leak where there was none.
- Treating a repeatedly blocking drain as a series of one-off clogs. If it comes back every few weeks, something structural is wrong - a sag, a partial collapse, or roots.
- Forgetting the overflow when plunging, which is why plunging so often seems not to work.
When to call a professional
Call a plumber if more than one fixture is affected, if a toilet bubbles when another drain runs, if sewage backs up anywhere, if the same drain blocks repeatedly, or if the auger meets something solid that will not clear. Repeated blockages in an older house often mean root intrusion or a failed section of drain, and both need a camera inspection rather than another go with a plunger.
Hiring a plumber
What Ontario requires, how to verify it, and what the work should cost.