Chucking some caustic soda down the sink along with hot water, and then allowing it to work its magic for a while, before flushing the pipes through with more boiling water did the trick (be mindful of the vapours).

May be worth a shot…

Of course it could just be that, as you suspect, you had a shoddy installation, but the first thing I will always try if I have the problem again is good ol’ caustic soda.

Gene: I did expiriment number 5000 on the sink and watched it drain. Water definitely drains slow but steady, however I hear a glugging noise down by the trap, even though there is no noticable stop-start-stop in the draining.

No toilets or anything above, this is on my top floor… and no drainage issues on the first floor or basement. You really think it needs to be snaked?? Can that much stuff build up in a year or two?

Okay, yes, probably. I have no idea why I’m so reluctant to do that.

Oddly there are no threads to tape. I mean, there are, but that isn’t where the water comes from. There is a pipe that slides in from the trap and then a seal, and the threadded part tightens down the seal. Because of my sink position, that seal (which should be on a straight part of pipe) is located on the curve of the trap. I pulled my whole cabinet about 2″ out of the wall so that seal could be tighened on the straight part and it seems to work okay. Go fig.

The slow draining could be lack of proper venting as handyman says, but the solution his friends used sounds questionable. Code requires the vent to be above the maximum water level, and you don’t sewer smells venting into your bathroom (there may be some special widget that allows for that.) When it drains, does it drain slowly but steadily, or does it blop, drain some, blop, etc.?

If it’s slow but steady, more likely it’s the drain partially blocked a bit further down. Snaking drains can be un-fun if there are any toilets above that level.

The faucet location shouldn’t have anything to do with it. - they are 2 totally different lines, one is supply and the other drain. They don’t intersect so the location of the faucet is irrelevant. The water could flow from the moon and it shouldn’t matter.

The slight angle. I guess it depends on the angle, but I can’t see that being an issue. It’s not as if its sloping 45degrees upward??? + the run into the wall is too short to likely cause a problem. It’s not like its running up hill for miles, probably only about 4 inches before it turns downward. I doubt thats it.

Sounds like a venting problem to me. You need adequate venting to create back pressure for water to drain. Poor venting, poor drainage… Are there any other sinks in the vicinity, or above that have similar problems. What about the tub? If yes, maybe there is no venting to this line…

Friends of ours had a similar problem, (I think) and created a little vent pipe right under the sink. It was a small upward piece of pipe just after the trap that allowed the air to vent but was high enough that water didnt come out. I think they had some form of cap too???. Never really seen this before so I can’t comment on how effective it is ???

Could be the main drain line is blocked, which would explain why it takes a while to back up… its a big pipe to fill up and that takes time - thus 16 seconds in before chaos ensues. Only roto rooter can solve that… or draino?

What happens if you fill up the sink and then pulls the plug? Just curious…

The leak is probably just bad plumbing connections. This can be fixed by using flexible rubber connectors instead of threads or glue. This is often used to connect pipes of different materials. It’s a rubber sleeve with 2 round clamps. Comes in many sizes at HD.

Oh yeah, if the trap is leaking at any of the threads… get the white silicone plumbers tape and wrap the threads before screwing it back together. The upward angle is probably what’s causing the leak cuz the trap isnt sitting straight, not the backup. It’s readily available in the plumbing section of HD too.

I am no plumber, just an architect, an writer and according to my wife - a handyman. Hope this helps….