Moving my shower drain about 5' over. Can some one check out my plan of attack?

Hi guys, admittedly, I am more of an ask for help than give advice kind of guy with home stuff. Catch me in an automotive forum and Ill help all day haha.

Anyway, I am redoing my bathroom in my second home here. It was 10x5 and I have removed the wall that went to a closet and added 5 feet. Where the closet and bathroom met, used to be the back shower wall. I now want to push the drain into where the closet used to be so I can make that space the shower.

So here's a few photos. Would it be okay to:

1: Move the vent hose over to where the new drain is and just have a longer run up in the attic?
2: If I move the vent near the drain, is it okay to then run the drain straight though the joists at 1/4 per foot drop to the original piping that was near the original vent connection?

Hope that was clear! If not, toss me some recommendations, I'm all ears. Joists are 16OC

EDIT the last three photos are turned to the side for some reason?

 

First you need to look at the elevations of your drain pipe and where they will be 5 feet away. Make sure you look over how much and where it is permitted to drill into floor joists.

 

I see no problem doing this as long as you satisfy a few conditions. In the UPC you are allowed to have the water in the trap to be no longer than 6' from the santee that provides the vent air. I can't tell from your photos but if the run from the trap is more than 6' then you will need to splice in a vent closer to the new shower location. We do this kind of thing all the time. Remember your vent air pipe must drop in on the top side of your horizontal drain pipe and you will need to use sweeping drainage fittings on the vent until it gets at least 6" above the curb of your shower. The idea being that if the drain ever clogged you are less likely to push junk up into the vent line and clog it, also if the lower part of the vent has soft turns then potential clogs will fall back downstream. Once the vent gets above that 6" you can tie it back into the vent system almost anywhere. If you can bring an 1 1/2" pipe straight up the studs into the attic and tie back into the same vent system it would be ideal. Remember your vent must slope downhill continuously also, no up and down moves, otherwise it will eventually fill with condensation, disabling the vent. Another common rookie mistake: the run between the p trap and the vent must stay on the horizontal, it should have 1/4" slope but no 90' or 45' downward sweeps until it gets to the vent. After you get tot the vent you can go crazy and maneuver it anyway you like. The idea here is to avoid siphonage of the trap.
The next problem I see is the current location of your p trap appears to be kissing the underside of the subfloor. If you extend the drain another 5' at 1/4" slope that trap will want to sit 1 1/4" higher than its current resting spot. You may need to go further downstream and lower the connection at the tee. If you are re routing the vent further upstream you might have an easier time by removing the old santee, removing the vent connection here all together, and replacing it with a long sweeping 90' or 45'. If you do that, remember you need to re establish a vent within 6' of the drain.
Rule of thumb for drilling joists is only drill in the middle third of the thickness, the middle third of the length, and don't remove more than a third of the wood, as most of the strength rides on the edges. If you end up needing to drill too close to an edge or end I would consult with the carpenters to make sure you aren't going to end up with a weak floor that will bounce your new tile work apart.

Hope that helps, good luck. You can return the favor by going to look at my fluorescent light problem over in the automotive section.

 

The considerations I made were that I would need to be 2" from the top of the joist when I start after the trap and at a 6 foot run, end up 1.5" lower or (3") total from the top of the last joist hole. The work area is about 3 feet-ish off the supporting wall of a total 15' run. This is all above my garage.

First issue you mentioned is the 6 foot max from water to vent. That's not a problem, it will be just under 6 feet to the current vent and if I move the vent, then it'll be closer so no worries.

As for the vet dropping in on the top, yes that may cause problems, the drain is 6inches from the wall so I'd be at the middle of the floor. Is the 1/4 run a min or an exact point. If I can have a deeper slope, I can just have a trap, make the 5.5 foot run so that it comes out at the end near the bottom of the joist (instead of the middle, then for the top drain connection I can have a sweep over to the original drain and then another sweep to connect it to that?

EDIt Ill check out your lighting thread too.

Here's a lower shot showing the current ending configuration. The "Main" pipe after santee is much lower (below the joist) does that help? I have access from the bottom here.

 

You want to maintain 1/4" slope if you can. it is the magic number that supposedly keeps solids in suspension while in water as it travels.

Code says 1/4" minimum on a drain. You should not exceed 1/4" per foot on a 5.5' trap arm as you may create a siphon.

If you have good access from underneath and the run from the trap to the vent is under 6', then I would install your trap where you need it, drill your joists with slope comfortably in the middle of the studs, and remove the existing vent santee, and install a new santee at the proper height to catch the waste coming out of the trap arm. Does that make sense? It would require you to splice in a coupling and a little bit of pipe on both the drain line downstairs and on the vent line above the floor, where you can easily work with it.

 

So I opened it up the rest of the way...if I could run a sweep on the drain at the end to under the current vent hose, it could work. Is that a no? or would that be ok? Here's a photo.

Drain to trap in the first joist runner, then travel the green line to last joist and sweep over to where the current vent is. Then I can have it dump right into the main line under there.
EDIT its 6' 3" exactly to vent from drain...the 3 " a deal breaker?

 

Ok I figured out the length problem, I can move over 2 joists with a side exit drain like this DRAIN

Just need to know if the long sweep to the santee is okay?

 

What's under the new shower location? Is there a wall downstairs that matches the bathroom wall that you could run down?

I'd feel uncomfortable drilling through all those joists. Not that it can't be done... but maybe there's an easier/better way?

 

The blue line is how the wall runs under the bathroom in the basement. With a side exit drain I can move over 1 to 2 joists and also eliminate 2+ feet from the trap arm.

Going to buy the stuff today, if it all looks good.