3" drain ok for bathroom addition & gas water heater question?

[GatorKenD]

Hi all - I have an unfinished detached building behind my house that used to be the laundry room. It is currently where our gas hot water heater, well equip and pool equipment reside. I want to move the well and pool equipment and convert the space into heated and cooled living space (bedroom and bathroom). I'll pull permits for the project and do some of the work myself. Still trying to decide if I want to hire a GC or bring in subs myself. Before I get too far down the pike on this, I wanted to find out if the 3" drain that currently runs the laundry end of the building is sufficient to handle the plumbing demands of a full bath (fyi, I'm in Gainesville, FL). Don't know if it helps, but attached a piece of the plumbing plan that includes this building (outlined in blue) and 3" drain (in red).

I have a second question as well: What should I be keeping in mind in terms of operating a gas hot water heater in an interior closet. This is something I will get pro help on as I don't want any guests getting carbon monoxide poisoning (ok... depends on the guest, right?!), but I'm a little OCD and want to make sure I know enough to properly look over someone's shoulder.

Thanks!
Ken

 

[Reach4]

I wanted to find out if the 3" drain that currently runs the laundry end of the building is sufficient to handle the plumbing demands of a full bath (fyi, I'm in Gainesville, FL). Don't know if it helps, but attached a piece of the plumbing plan that includes this building (outlined in blue) and 3" drain (in red).

Sufficient. Where will the toilet be located? Where will the tub/shower be and where will the lavatory be? Toilet last is better if it does not matter. The lavatory can probably vent all 3 pieces.

Are the H, C, and W lines in the slab? Those could interfere with slab cutting. Sometimes it is easier to connect and route stuff outside of the slab. Another possibility to minimize the slab cutting is a rear-outlet toilet.

I am not sure what separation is needed for the bathroom vs WH.

 

[Sponsor]

 

[GatorKenD]

Sufficient. Where will the toilet be located? Where will the tub/shower be and where will the lavatory be? Toilet last is better if it does not matter. The lavatory can probably vent all 3 pieces.

Are the H, C, and W lines in the slab? Those could interfere with slab cutting. Sometimes it is easier to connect and route stuff outside of the slab. Another possibility to minimize the slab cutting is a rear-outlet toilet.

I am not sure what separation is needed for the bathroom vs WH.

The building is only 7' deep, so my plan make the poured concrete foundation about 9' deeper. I'm thinking I can tie the new drain pipes into the 3" clean-out marked in the drawing. That'll give me the opportunity to place the new drains before new concrete is poured. Because of the location of the hot water heater immediate adjacent to laundry, I've got easy above-slab access to hot/cold water supply.

 

[Reach4]

The building is only 7' deep, so my plan make the poured concrete foundation about 9' deeper.

The ceilings in the outbuilding are 7 ft above the floor and the foundation is what? Goes 9 inches or 9 ft below the floor?

How about making a prospective floorplan of where the toilet, tub, and lavatory might go.


I would tend to think you wye into the 3 inch, and leave the planned cleanout where it is. I drew a layout that probably does not match what you have in mind.

 

[GatorKenD]

The ceilings in the outbuilding are 7 ft above the floor and the foundation is what? Goes 9 inches or 9 ft below the floor?

How about making a prospective floorplan of where the toilet, tub, and lavatory might go.


I would tend to think you wye into the 3 inch, and leave the planned cleanout where it is. I drew a layout that probably does not match what you have in mind.

miscommunication is mine... the footprint of the building is 42' x 7'. I'm going to make it 9' deeper, i.e., 42' x 16'. The 3" cleanout comes out on the backside of the building where I have the new slab installed.

 

[Reach4]

deeper

So deeper to you is the dimension away from the street.

That doesn't affect my drawing much, does it?

 

[GatorKenD]

So deeper to you is the dimension away from the street.

That doesn't affect my drawing much, does it?

This illustration will give you a better idea of what I had in mind. The area I have designated for the bathroom will be part of a new slab. Because of the location where the cleanout is (circled) and the access to hot and cold water supply above-slab (at the water heater). I think plumbing the new bathroom will be easy.

My main question, though, was about the 3" drain. It's what makes the plumbing part of this project easy (that being a relative term!). I understand that local codes can vary, but is it likely that 3" will generally be code compliant in most locales?

 

[James Henry]

3" Is more than enough.

 

[Reach4]

I left a blank one for somebody else to draw lines on.

 

[James Henry]

 

[James Henry]

Sorry, I was bored.