Schussing the Pedestal Sink (out of the closet).


What’s wrong with this loose pedestal sink? (not counting that it’s loose)


Pedestal Sink

If you looked underneath or ran your hand down the drainpipe, everything is smooth, straight, clean, no leaks.  The drain stopper lifter needs adjustment, but that’s just maintenance.

The taps are good, tight, no leaks or drips. The speedways and shut off valves are correct and working.  And again there are no leaks or drips or corrosion.

Everything is tucked neatly behind the pedestal base. The wall attachment bracket that holds the sink body to the wall needs to be tightened.  Again it’s minor maintenance.

So what’s wrong?

If everything you are seeing (or I’ve described for you) has only some minor adjustments, what is it?

What are you not seeing?

 Go back to the first line of the description “the drainpipe, everything is smooth, straight, clean, no leaks.”

Have you got it yet?

Well let’s go down and look up.  No, not under the sink.  It’s not there.  I mean right down to the basement.


Here we go. Now look up. (down at the second picture)


Sink Trap under floor

Now you can see the trap, the water trap that was missing upstairs.

‘So what’s wrong with that? There’s one on the line’ you might be thinking. And yes there is one, we can see it.

You might think that makes sense for a pedestal base sink. It certainly would make it easier to fit all the plumbing behind the pedestal. 

 So what’s the problem?

It’s the vertical distance the trap is below the sink basin. Here it’s more than 3 feet. A correct installation is within 12 inches of the sink basin (vertically).

 The function of the trap is easy to understand.

 The “U” section keeps water trapped there and prevents unwanted (smelly) sewer gases from traveling up the pipe and into your house (plus small varmints, spiders and bugs of all descriptions).  So as Martha Stewart would say “That’s a good thing.” And we’d all agree.

 Normally when you ‘pull the plug’ of your sink the water drains down through the trap and out the drainpipe and the last cup or so of water remains in the “U” area of the trap, recreating the seal.

 As this is installed what happens is; the sink load of water plunges straight down the drainpipe and hits the U-trap at a good rate of speed and this mass of water is going fast enough to cause hydraulic suction to pull all the water through the U-trap.

 So that means the trap is open, no water is left there to create the seal.  Now that it is dry, even a smaller amount of water can ‘schuss’ down the pipe like a bobsled runner and carom right though the trap.

The trap is still un-sealed.


Hmm.. I wonder how much “air freshener” gets purchased for this home, or does the homeowner (likely the plumber here) know to slowly dribble water to fill the trap again.

 This is a small powder room that has been added on the main floor. It is a converted closet. It’s small, so small that that is why the sink is loose.

Yes, people hit their hips against the sink trying to squeeze past to get to the toilet beyond it.  That’s small.

 And that toilet, guess what, it’s loose too. The same absence of plumbing know how has been applied here as well.




Original blog post on ActiveRain: Link to Blog Post