P-traps under slab for sinks?

[jsumrall]

I'am looking at building a small shop 20 x 10 on a slab foundation with a bathroom including toilet shower and lavatory. I am looking to do most the work myself including plumbing. My question is do I need to install a p-trap under the slab for the lavatory drain ? If I'm correct in thinking only the shower drain will need one since the toilet and sink will have a p-trap installed.

 

[phishfood]

Your thinking is correct. The shower will need a Ptrap under slab. The toilet has a Ptrap as part of the toilet itself. The lavatory will have one installed directly underneath of it, at the time that you install the lavatory.

You will need a vent for all of these fixtures, though.

 

[Caduceus]

If I understand your question correctly, you are asking if you need a separate trap for the drains after they all connect, under the slab. This would also be described as a building trap for the building main sewer. If what you are constructing is an addition to an existing building and you are connecting the main drain to an existing sewer from an adjacent structure, then another trap under the slab is not necessary.
If the building is standing independently and you are installing a new building drain that connects to a sewer main or septic that is outside of the building, then you may need a building trap depending on your local codes. In my area a building trap is required, but IPC plumbing code does not require one.
As phish said, be sure to provide vents for the fixtures.

 

[LeakFinder]

You got it! P Trap on the shower drain but not on the sink drain. Be sure you install them correctly as backed up showers and drains can cause black mold and water damage. Hidden leaks may require a leak detection service in order to find them. All these things can be very expensive if plumbing lines are not installed correctly!

 

[Caduceus]

How do we get rid of the LeakFinder-Bot? Seriously. Am I the only one who has noticed? Blah, blah, blah...black mold link, blah blah, water damage link, blah blah, vague agreement, blah, leak detection link.

 

[phishfood]

Caduceus, I have been noticing LeakFinder's linkladen posting too. I checked out LeakFinder's other posts. None of them have been very helpful, all of them are riddled with hotlinks to other sites (probably his). So I am about to report his post here, so that the moderators will give LeakFinder a close look.

I really don't want this site to become a spam mecca. I don't have a problem with people having links to their companies in their signature line, as long as their posts are helpful to the original poster. But some are just here to use this forum as an advertisement, instead of trying to help people.

 

[Otahyoni]

I pointed this out to Austin. I'll mention it again and see what he says...

 

[phishfood]

Thanks. dot dot dot to ten characters

 

[Chris]

We are working on it.

 

[Otahyoni]

I think i have the issue resolved.

 

[daza87]

If I understand your question correctly, you are asking if you need a separate trap for the drains after they all connect, under the slab. This would also be described as a building trap for the building main sewer. If what you are constructing is an addition to an existing building and you are connecting the main drain to an existing sewer from an adjacent structure, then another trap under the slab is not necessary.
If the building is standing independently and you are installing a new building drain that connects to a sewer main or septic that is outside of the building, then you may need a building trap depending on your local codes. In my area a building trap is required, but IPC plumbing code does not require one.
As phish said, be sure to provide vents for the fixtures.

Thanks for that, I had a similar question which you've now answered.