Putting an bathroom on a raised basement floor

[dwill7000]

I have all the plumbing roughed in for a bathroom but they were put in an awkward location, right in front of a large window. What Id like to do is put a toilet, tub and sink further back in the basement which means putting in all new sewer hookups. But I hate cutting concrete and noise is an issue.

So I thought Id put the whole bathroom on a raised wooden floor. The main stack from upstairs is only about 5 feet away from where Id locate the toilet.

1. Can I hook the tub and sink into the toilet drain or does it have to run separately?
2. Does it all need to be vented or can it do that through the main stack?
3. How much slope and therefore how high would the floor have to be to make a 5' run?
4. As long as I build a solid floor (7/8' plywood) and theres no flex, is there any issue with building on a wood floor thats over concrete?

Thanks. Appreciate any help.

[patrick88]

1. Can I hook the tub and sink into the toilet drain or does it have to run separately?

yes with vents

2. Does it all need to be vented or can it do that through the main stack?

vents are needed. if you don't when you flush the toilet upstairs the trap for your fixtures down stairs could empty and cause your basement to smell like sewer .

3. How much slope and therefore how high would the floor have to be to make a 5' run?

you need a pitch of 1/4" per foot.

4. As long as I build a solid floor (7/8' plywood) and theres no flex, is there any issue with building on a wood floor thats over concrete?

you would be much happier opening the floor. It would be much nicer looking if you just open the floor.

[cwhyu2]

Iagree with pat to step up to a bathroom is not good.
Open the floor up and when it is done you will be much happier.

[GrumpyPlumber]

Make that three.

[acjensen]

ditto, that's what i'm doing.

[Gary Swart]

Raising a tub or even the whole bathroom floor for a drain is a hack job. There are companies that cut concrete and would have this job done in very short order. Besides being fast, they are clean, will remove the concrete they cut out.

[geniescience]

... companies that cut concrete ... are clean...

there is never dust; that's how clean they are! They use a wet saw that sprays water on the cut as the blade makes the hole or the straight cut. You won't have that dangerous microscopic dust that concrete makes.

david

[thezster]

I hope their equipment is more modern than what I rented yesterday. I rented a walkbehind concrete saw, with water sprays, diamond blade, etc., etc....... Yet the basement I was cutting still filled with both concrete dust and engine exhaust to the point that we could barely see through to the opposite wall......

On the other hand, cutting the floor was easy as slicing bread - taking little over an hour to make a 15' X 1' rectangle.......