Need plumbing advice - venting fixtures

[sleepy hollow]

I am building a full bath in my basement. This includes adding a sewage ejector pump since my main waste stack drains to septic fields at about 5 feet up from the basement floor.

The bathroom will be about 5 x 10 feet, with long side against basement foundation wall where main waste stack runs. So, it is 6 feet straight up from pump to waste stack.

I am adding the following fixtures:

Toilet
Bathroom sink
tub/shower
Bar sink
Ejector pump

The layout is posted in the attached powerpoint file below

Ok, I have run a new 2" vent line to vent these fixtures.

I plan to drain the toilet directly to the pump basin using a 3" to 4" line (the size of the basin inlet).

On the way to the basin (2-3 feet) the 3"/4" line will pick up the following:

1) The bar sink and the lavatory sink drains. I will run the lavatory drain around from the back wall and connect to the bar sink drain. The drains will be 1.25" pipe (I think) connecting immediately to 1.5" runs to 2" combined drain down to the 3"/4" main drain right next to toilet.

2) The tub drain which slopes directly from the tub drain (I assume 1.5") to a 3" run to the main 3"/4" drain.

Now for venting:

The sinks are separately vented using 1.5" pipes that connects to the 2" vent stack. Vent takeoffs are just after the P-traps, one in the foundation wall, and one in the left wall.

My questions center on how to vent the toilet and tub.

I think I can use the 2" sink drain (or 3" if needed) to wet vent the toilet, yes?

As for the tub, do I need a vent that takes off right at the p-trap (see drawing) or can I have the vent takeoff near the connection to the 3"/4" drain, about 7-8 feet away? Is that too far?

The pump is vented to the 2" line as well. Basically all vents are tied to that 2" line.

Also, I am a little fuzzy on standard drain sizes and how big/small they are. What is typical for a bar sink vs. lav sink, vs tub drain?

I am using all PVC pipe.

Thanks.

Also, I welcome any and all suggestions, even beyond just the venting.

[bkrahmer]

Code in Idaho is that nothing in concrete is to be less than 2". I asked the inspector why, and he says it has to do with cleaning a line. That made sense. I would recommend using that advice.

The distance to your vent for your tub sounds long. That one is going to depend on your local code. Closer is always better.

Wet vent depends upon your definition. I have the Black & Decker plumbing book, and their diagram and explanation of wet venting is a crock. Idaho code says you can't wet vent horizontally. We have to vent each fixture individually before it joins anything else horizontally. You can then join the vent pipes once they're out of the horizontal plane where the waste line is.

One point of advice, don't use multipurpose glue. If you're using PVC, use the purple solvent and PVC glue.

[sleepy hollow]

Thanks for the advice. One thing the diagram does not show is that the only lines under concrete are the toilet to pump basin and the tub to 3/4" toilet line. The drain from the sinks also becomes a 3" line before entering the concrete. So, I think I am ok with that part of the code. As for the tub vent, I believe I have learned that 5' is the max to vent takeoff. So, I will have to vent where I show in the diagram. No big deal.

As for the glue, I would only use the purple primer, glue combo. Works too good to consider anything else.

Do you see any problem with the toilet vent as shown, being a wet vent from the 2 sinks drains? By the way, the wet vent is vertical, that is greater than 45 deg., not horizontal, since the drain drops straight down to the 3"/4" line from the bar sink. And the vent takeoff from the bar sink is also vertical, and can be in line with the sink drain where it goes from horizontal to vertical.

The diagram is not exactly the way it will/can look.

For exmple, I can also run a separate vent line off of the top side of the sink drain lines. Or, I could run a completely separate vent from the drain line entirely, but that seems like overkill. I am mainly looking for confirmation that this combination 2-sink drain and toilet vent will work, and may not be that unusual.

Thanks again.