Help laying out attic bathroom

[Steven JP]

I am finishing my attic and laying out the bathroom is quite difficult. I attached a picture of what I think is the best option. The grey lines are the joists and the one thick grey line is a beam that spans the house where the joist connect. The sloped side (roof side) is on the toilet side so I'm trying to keep the vanity and shower away from that side. As you can see in the picture my drain line is far away from the toilet. I was thinking of putting a rear draining toilet in so I would not have to raise the whole floor. I have never used one of these. Since my drain is almost 9 feet away I would need 2.25 inches of slope in my drain. Would a rear facing toilet accomplish this?
Also, with my layout, the drain for the shower will be right over that beam. Any suggestions on that. I suppose I could just raise the shower but I'm trying to avoid that.
Any other options anyone can come up with would be helpful. Thanks.

 

[James Henry]

Also, with my layout, the drain for the shower will be right over that beam. Any suggestions on that.

https://www.faucet.com/right-drain-shower-bases/c83533

 

[Sponsor]

 

[James Henry]

If I were you I would relocate and redo the layout of the bathroom to make most of the plumbing pipes run in between the joist's.

 

[Steven JP]

Damn why didn't I think of that. Haha. So then what would you suggest. I can't put the toilet in the same joist as the 3 inch pipe so there is no other option for toilet other than raising the floor.

 

[Terry]

If that is a vent for the lower floor, it can't be used for waste. Find another way to drain that bathroom.

This is your attic? How deep are the joists? Unless they are 2x10 you can't run waste for a toilet through them. If they are 2x10, a shower drain over the beam would fit. Maybe not on 2x8 or smaller.

 

[Steven JP]

No this pipe is servicing nothing right now. I moved some stuff around in a bathroom awhile ago and ran a whole new vent pipe and freed this one up for this project.
Yes this is an attic. They are 2 by 8s joists which is why im trying to figure out a way to get my drain pipe from the toilet to the main drain. The toilet is 9 feet away which gives me 2.25 inch drainage slope requirement. Will a rear drainage toilet work. If the bottom of the drain pipe for the toilet is more than 2.25 inches off joists then that should work. I just have never worked with one of those toilets so that is why I'm asking.
As far as the shower goes I think I might just have to make that a raised shower unfortunately.

 

[Tuttles Revenge]

We have plumbed a few attic bathrooms lately. Finding an appropriate drain will be your biggest challenge. Also consider if the joists or floor structure is even suitable for the purpose. ( ignore this as I started typing before your prior post)

I found the Duravit toilet has the highest trap weir at around 7 or 8 inches which will give you the most travel over your attic space.. Your shower will be the another challenge because the trap dips down often thru the ceiling below.

 

[Steven JP]

The rest of my house is 2 by 8 joists and that's been doing fine.
So the whole back drain toilet and running the pipe over the joists isnt an unheard of thing? That's good to know.
If it wasn't for the main beam in the middle of the attic floor the shower wouldnt be a problem. 2 by 8 is enough room to run a shower drain. The first post on here was about different bases for showers with offset drains but looks like they are 600 dollars just for the base. If it came down to that I'd just end up raising the shower.

 

[James Henry]

https://codes.iccsafe.org/content/IRC2018/chapter-5-floors



Just to keep things complicated I've included this for your reading pleasure.

 

[Steven JP]

Ah so that thing I've been calling a beam is actually a header.

 

[James Henry]

Basically what I was pointing out to you was, When is a house is designed by a professional the floor joist's are sized and spaced to support "live" and "dead" loads according to the type of lumber used, so ceilings and attic floor joists are not sized to support furniture, appliances, bathrooms, etc. so you should check the" lumber span tables" in the code to see if you need to beef up the floor.

 

[Steven JP]

Well that's not what I'm trying to get help with right now. The rest of my house is same lumber and spacing. I need help with my bathroom. I appreciate the help. Sorry but this happens every time I start a post, someone asks about the joists.