# Shower Trap Question

• posted on September 13, 2004, 10:11 am
My shower stall has a 2" pipe for the drain, running into a 2" trap, etc. It's 2" all the way. Anyway, I need to shorten the straight piece running into the trap. The trap was set in a little low to the ceiling below. I want to be able to give it a little more room. What should be the minimum distance from the shower drain to the trap below? I know gravity does the work, but I want to make sure the drop is sufficient for the water to run.
Thanks,
John
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
• posted on September 13, 2004, 1:27 pm
JJ wrote:

The "drop" can be anything you want. What matters is that the horizontal pipe from the trap have some pitch to it: about 1/4" per foot will do it. I don't see any problem with what you plan.
Jim
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
• posted on September 14, 2004, 10:27 am
After looking at this thing a little more in depth:
I need to raise the trap about 1 1/2". If I shorten the straight piece by about 1 1/2" then obviously it is not going to line up with the pipe going to the sewer. Right now, the trap is perpendicular to the joist. So, there is no room to add any type of fitting to get it to line up. So, my initial though is to:
Turn the trap away from the joist enough to put two 45s in, they will have about an 1 1/2" drop, and move horizontally enough to line up with the pipe. Would this work, and avoid an S trap situation?
Thanks,
John

want
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
• posted on September 14, 2004, 4:06 pm
JJ wrote:

Technically, that may create a problem. I'm assuming that the vent connection is further downstream (sounds like). The "trap weir" (the lower edge of the trap outlet) must not be set higher than the vent connection *inside* the TEE.
If the rule is not followed, there is possibility of trap self-siphonage, although in a shower basin it is probably unlikely.
GOOGLE: trap + weir + vent for more.
Jim