basement bath pipes (pic)

[qas]

Before I cover with cement, is the layout of my basement bath okay? The vent I am planning will be 2 inches and run 2 feet horizontally, up 3 feet, then another 5 feet horizontally and tie into an existing 2 inch vent that extends through the roof. does the shower require a vent and what about the sink?

Thanks.

[LazyPup]

SEE THE NOTES IN THE ATTACHED PHOTO.

The codes prohibit the use of sanitary Tee's on a horizontal line. You must use a Wye fitting and you can then use a 1/8 bend (sanitary 45deg) to either turn at right angles or parallel to the pipes.

If you are under the International Residential Code the 2" shower line may run a maximum of 8' measured on the top of the pipe from the junction into the 3" main drain to the shower Trap. If you are under the Uniform Plumbing Code the length is limited to 5'. If the length of run exceeds these limits you would need to install an auxillary vent within those limits.

A vent line may not run horizontally until it it 6" above the flood level rim of the highest fixture served by the line.

The vent on the water closet line is not necessary and in fact a water closet will flush much better if the nearest vent is at least 3' away. (Vents are required to prevent the water in the traps from being syphoned out, however a water closet actually works on a syphon principal so having a vent too close will retard the rate of flush. In order to insure a water closet will not be left with a dry trap the fill valve has a trap primer line to refill the trap after the flush.)

You can install a 2" Wye and 1/8bend and run a horizontal line to the lavatory. Turn the line upwards through the wall behind the lavatory and install a Sanitary TEE (A Wye is prohibited here) and run a short waste arm out to the lavatory. Continue the 2" riser upwards until it is 6" above the flood level rim of the sink, then you can turn it horizontal and connect it to the existing 2" vent to the roof. The 3" under the floor would then be vented through the lavatory riser and the tub line is venting off the 3", provinding of course the length of the line from the 3" to the shower drain is within the above stated limits.

[qas]

The vent that will server the lavatory and everything else, can it be 1.5 inches and then increase in size 6 inches above the sink to 2 inches?

Thanks for the help!

[LazyPup]

Yes,, an auxillary vent is only required to be 1/2 the diameter of the pipe it serves therefore it can be 1-1/2". Tying into the existing 2" is no problem.

[qas]

Can a cleanout be 2 inches and server the 3 inch pipe?

Lazy Pup, thanks for the help. You have been great!

[LazyPup]

The code minimum cleanout opening for a 3" line is 2-1/2".

A toilet can be lifted and thereby allowing a direct access into the line, so the toilet will serve as the required cleanout for the line from the toilet flange to the 45deg bend.

From the photo it appears that you will need to break out a bit more concrete at the 45deg bend. You can then install a Wye on the end of the line from the wall to the bend and attach the line from the toilet to the bend on the side opening of the Wye.

On the end of the 3" WYE you can install a 3" 1/4 bend turning upwards. You can then install a cleanout cap on the 1/4 bend which should leave the cleanout at or slightly above the floor level.