Vent elbows and flex drain line

The flippers are back!!!
“S” trap with vent elbows, flex line at bath tub.

Looks like more work to do it wrong than to do it right.

I’ve never seen one of those flex lines before but it looks like they’re made for plumbing. Is there anything wrong with them?

Yes,they all must be smooth wall I.D.

Granted easy to remove, but still wrong.

Here in CA this type of flexible plastic drain piping assembly can be found in pretty much any hardware store (Home depot, Lowes, Ace). I personally would not recommend this type of install, I prefer rigid piping myself, Even though the flex piping are quick and easy to install they are more likely to cause clogging (especially at disposal) and sagging along the flexible ribbing. Also in some states this may not be a proper install.

This question comes up all the time, and the consensus is that they are not approved, yet they are sold in all hardware stores, and no one has ever been able to post anything that specifically states why (or where the info is) that they are not approved. This occurs on all the relevent MB’s, not just here.

From State code

j) No fittings having a hub in the direction opposite to flow, or tee branch, shall be used as a drainage fitting. No running threads, bands, or saddles shall be used in the drainage system. No drainage or vent pipe or fitting shall be drilled or tapped.

k) No fitting, connection, device or method of installation shall be used which obstructs or retards the flow of water, waste, or air in the drainage or venting system by an amount greater than the normal frictional resistance to flow. The enlargement of a 3 inch closet bend or stub to 4 inches shall not be considered an obstruction if it is necessary to increase the bend or stub at the floor line to 4 inches in diameter in order to accommodate the water closet outlet.

Section 890.370 Prohibited Joints and Connections in Drainage Systems

Drainage System. Any fitting or connection which has an enlargement, chamber, or recess with a ledge, shoulder, or reduction of pipe area that offers an obstruction to flow through the drain is prohibited. No fitting or connection that obstructs flow shall be used. In existing buildings only a flow control valve or device may be connected to the fixture drain and shall not be considered as an obstruction. The enlargement of a three (3) inch closet bend or stub to four (4) inches shall not be considered an obstruction.

Type of Traps. Traps shall have a uniform and smooth interior, and shall have no partitions or movable parts. The trap seal shall be non-adjustable. (See Appendix D: Illustration C.)

Thanks for posting the info, but, if you are applying the info to Jeff’s pictures, I will bet that it does not apply. I would say the AHJ (if one was involved) approved the work. Carefully read and understand what each code states, and then look again at each pic. Yes, minor technicalities will get the builder/plumber approval almost every time, especially in Chicago.

I call them out, but unlike you I am not a code inspector.

Illinois code as I listed above does not allow their install however.

The accordion violates portions I bolded Jeff, however next time I will add a flashing arrow.LOL.

Note: On virtually every flexible P-trap that I have seen, the "flexible’ section is at/above the straight/verticle/tailpiece section, and is not technically considered the trap. On the “soft rubberlike” P-traps, they are always “smooth” interiors.

Also note Bob: Running threads are more apt to electrical conduit, but technically applies to plumbing also…

“Running Thread”…
You don’t feel this design obstructs waste?

Jeff is trying to be difficult and must have stock in one of these companies…seriously dude
just use common sense.

If the inside diameter is 1-1/4 is that at the widest or the most narrow part of the accordion?
Do you even know and when you figure that out explain how the valley part does not constitute making the diameter smaller at any point.

The inside diameter is changing from small to big to small again and that is not allright even in laymans terms.

Perhaps in your opinion it is OK to go from 1-1/2 to 1-1/4 also ?

Only minimally… AS SHOWN… the bellows are basically pushed together/closed, not extended open. Take a close look, and the next time you are in HD/Lowes/etc… check one out, and you will see what I mean.

This is from a post in 2009. Is this still a factor in Illinois?

Not approved in IL, and no code inspector was involved, and even if one was, it’s Chicago, that we we have work here. Just the tip of the iceberg in this house.

And like Jeff said, that is in the entire State of IL, not just Chicago.