Plumbing layout help

[Caryncbreeef]

Hello all, Just getting ready to rough in the house I am rehabbing. Two bathrooms and a kitchen, single level, pretty darn tight crawl.

I’m running Pex A with a manifold system. My questions are about the DWV system. A friend who is a plumbing inspector came over and laid out for me what I need to do. He suggested one vent through the roof for the washer, slop sink and shower. He said Studors for everything else. (small home, cathedral ceiling so no attic. He told me which fixtures to put in groups. G0t all that but I know there is more to it than that.

while I understand what he described, in researching I understand it is slightly more complicated than that. which fitting are required where, exactly what inspectors want to see, etc. Like which connectors are required when directions change.
He is not able to really give me this detail I would prefer to have before doing the work. I am looking for someone to do a drawing for me with specific fitting required (i have drawings of the plans already). I wouldn’t expect it for free. I want to do the work correctly the first time if possible. Any suggestions would be great.

 

[wwhitney]

How about a floor plan?

Wayne

 

[Sponsor]

 

[Sylvan]

" I want to do the work correctly the first time if possible. Any suggestions would be great."

Then hire a local master plumber to either do the actual work or layout what you need exactly

 

[Caryncbreeef]

" I want to do the work correctly the first time if possible. Any suggestions would be great."

Then hire a local master plumber to either do the actual work or layout what you need exactly

Getting a -lumber in Raleigh is about impossible these days. No one even answers messages. The one that did wanted double for rough in than the electrician! Thanks

 

[Caryncbreeef]

How about a floor plan?

Wayne

Ii will post it later. thanks

 

[Caryncbreeef]

How about a floor plan?

Wayne

Here is the floor plan. It was suggested that in the main bathroom, I pair the left lavatory with bidet and a single AAV. Second lavatory with toilet and single AAV. Shower vented to air. In utility room laundry tub vented to air washingmachine vented to air (all three connect with into one). Planned second bathroom lavatory toilet one AAV, tub its own AAV. Kitchen and island sinks on their own. I have that clear, it is the little things, what fittings for directional changes, where for example, the 2“ lavatory drain meets bidet drain, on way to main drain, what fitting at those connections? Water lines will be PEX A, house has a very small crawl, and ceiling is cathedral. Over the three little rooms in the middle of the house are ceilings, attic/storage). No where else. Thanks

 

[wwhitney]

Where's the building sewer you need to connect to?

Cheers, Wayne

 

[Caryncbreeef]

Where's the building sewer you need to connect to?

Cheers, Wayne

Sorry, it runs just to the left of the shower, starting at the bottom of the house( drawing bottom). There is newer PVC 4” connected outside to the newer cast iron. right now there is a fitting sending a three inch line out toward kitchen, and a cap on the 4”. To get to the utility room and bathrrom in the back the line will have to climb or break through some old foundation walls(that are not doing anything). I can take pics tomorrow. Thanks

 

[wwhitney]

OK, here's an example of a possible layout for the DWV, primarily the horizontal under floor pipes, although the line behind the double lavs would be in the wall. Various comments:

- This assumes the crawl is wide open and drains can run any which way. If you want to stick some of the drains up into the joist bays, you can do that with some limitations (mainly the trap weir rule on the tub/shower). I could advise on that if you show which way the joists run, and any obstructions below the joists such as girders, etc.

- Red is 3" minimum, green is 1-1/2", blue is 2", and purple means a pipe that the IPC allows to be 1-1/2", but where I would use 2" because it seems better to me.

- I don't have any experience with standalone bidets. From what I read, they are plumbed like sinks, usually with the trap above the floor and the trap arm entering the wall, and that's how I drew it. If you have a trap below the floor, then the bidet could be wet vented, just like the tub is.

- The green circles are 1-1/2" dry vents. Every fixture needs a vent, and only the bathroom fixtures can be wet vented. So there are dry vents for the kitchen sink, laundry sink, washer, bidet, and one lav in each bathroom. Then both WCs, the shower, the tub, and the 2nd lav in the upper (on the page) bathroom are wet vented.

- Each dry vent can either go through the roof or be an AAV. For a sink over a cabinet, an AAV can be in the sink cabinet, at least 4" above the trap arm. Other AAVs would typically be in a box in the wall with a louvered cover to admit air, also at least 4" above the trap arm. At least one dry vent has to go through the roof.

- I'm unclear on whether the IPC requires a 2" vent through the roof since you mentioned a 4" building drain. You don't actually need any 4" drains inside the building, but any of the 3" drains could be made 4".

- You mentioned being unsure of what fittings to use where, so if you want to ask that, I would suggest marking up the diagram with some letters and asking your questions in reference to the marked locations.

Cheers, Wayne

 

[Caryncbreeef]

OK, here's an example of a possible layout for the DWV, primarily the horizontal under floor pipes, although the line behind the double lavs would be in the wall. Various comments:

- This assumes the crawl is wide open and drains can run any which way. If you want to stick some of the drains up into the joist bays, you can do that with some limitations (mainly the trap weir rule on the tub/shower). I could advise on that if you show which way the joists run, and any obstructions below the joists such as girders, etc.

- Red is 3" minimum, green is 1-1/2", blue is 2", and purple means a pipe that the IPC allows to be 1-1/2", but where I would use 2" because it seems better to me.

- I don't have any experience with standalone bidets. From what I read, they are plumbed like sinks, usually with the trap above the floor and the trap arm entering the wall, and that's how I drew it. If you have a trap below the floor, then the bidet could be wet vented, just like the tub is.

- The green circles are 1-1/2" dry vents. Every fixture needs a vent, and only the bathroom fixtures can be wet vented. So there are dry vents for the kitchen sink, laundry sink, washer, bidet, and one lav in each bathroom. Then both WCs, the shower, the tub, and the 2nd lav in the upper (on the page) bathroom are wet vented.

- Each dry vent can either go through the roof or be an AAV. For a sink over a cabinet, an AAV can be in the sink cabinet, at least 4" above the trap arm. Other AAVs would typically be in a box in the wall with a louvered cover to admit air, also at least 4" above the trap arm. At least one dry vent has to go through the roof.

- I'm unclear on whether the IPC requires a 2" vent through the roof since you mentioned a 4" building drain. You don't actually need any 4" drains inside the building, but any of the 3" drains could be made 4".

- You mentioned being unsure of what fittings to use where, so if you want to ask that, I would suggest marking up the diagram with some letters and asking your questions in reference to the marked locations.

Cheers, Wayne


View attachment 81605

Thanks so much Wayne. This is really helpful. I will go over this with some questions tomorrow when I'm in the house.
as far as wide open crawl, the front of the house has an old foundation wall that required the 3” drain towards the kitchen to go up a bit to get to that Level. Here is how it was done but not sure of these are correct for this change of height. The 3” going to the bathroom and utility room will also have to rise up about 10” over another block old foundation to a higher dirt level, and then a little more to reach the bathroom. Here is a pic. MOre tomorrow. Thanks again.

 

[Caryncbreeef]

Thanks so much Wayne. This is really helpful. I will go over this with some questions tomorrow when I'm in the house.
as far as wide open crawl, the front of the house has an old foundation wall that required the 3” drain towards the kitchen to go up a bit to get to that Level. Here is how it was done but not sure of these are correct for this change of height. The 3” going to the bathroom and utility room will also have to rise up about 10” over another block old foundation to a higher dirt level, and then a little more to reach the bathroom. Here is a pic. MOre tomorrow. Thanks again.

I tried to post pictures but file size too large. Will retake tomorrow. Got it figured out.one pic is on the cleanout a foot or so before the 4” leaves the building. Is that an okay place? There was one ther in cast iron before. Then the other two fittings to get the 4-3 up over block wall to kitchen. Is this acceptable or do I need different fittings? Again thank you

 

[wwhitney]

Cleanout seems fine, not a detail I've studied. On the picture of the junction, the requirements are that the wye branch be sloped up 2% (to provide slope for the short horizontal section) and that the lower 90 be a LT90. The upper 90 can be a quarter bend or a LT90.

Cheers, Wayne

 

[Caryncbreeef]

Cleanout seems fine, not a detail I've studied. On the picture of the junction, the requirements are that the wye branch be sloped up 2% (to provide slope for the short horizontal section) and that the lower 90 be a LT90. The upper 90 can be a quarter bend or a LT90.

Cheers, Wayne

Thanks! Working on the rest and will post agin ina a day or so. Poured footings today, first good weather. been working on this project since 9/20. Just trying to move in before summer!

 

[Caryncbreeef]

How about a floor plan?

Wayne

Here are the drawings I did. Tried to post yesterday but everything seems to crash. I’ll add descriptions in second post

 

[Caryncbreeef]

The two drawings overlaying house plan just show main branches. One with pipe size one with elevation changes and hopefully correct fittings. Main bathroom has bidet/lav. Wc/lav. Shower and overall plan. Utility room has one. Kitchen. And second bathroom. Any suggestions would be appreciated. I tried to do as much research and considering joist and foundation placement so I could actually plumb what I hope to. Thanks

 

[wwhitney]

I will look through your drawings when I have a chance. It appears that on some you are trying to show three different dimensions on a page, which is confusing. Sticking to floor plans (vertical pipes are circles without their length shown) or elevations (one dimension is vertical, one is horizontal, and again pipes in the other horizontal dimension are just shown as circles) is clearer. Or drawing an isometric.

On the bidet, what model is it? Or more importantly, is it a rear outlet bidet or a bottom outlet bidet?

Cheers, Wayne

 

[Caryncbreeef]

I will look through your drawings when I have a chance. It appears that on some you are trying to show three different dimensions on a page, which is confusing. Sticking to floor plans (vertical pipes are circles without their length shown) or elevations (one dimension is vertical, one is horizontal, and again pipes in the other horizontal dimension are just shown as circles) is clearer. Or drawing an isometric.

On the bidet, what model is it? Or more importantly, is it a rear outlet bidet or a bottom outlet bidet?

Cheers, Wayne

Yeah sorry about that. I could split it up if it’s top confusing. Isometric on computer was hard. Bottom bidet I believe. I’ll get. Model tomorrow. Thanks. No rush. In Chaplaincy training this week won’t be doing any work til Monday.

 

[wwhitney]

Here are the drawings I did. Tried to post yesterday but everything seems to crash. I’ll add descriptions in second post

OK, I'm going to refer to the drawings based on the last 5 digits of the URL. I also am listing them in the order I see them:

81794. Looks fine: a lav vented with AAV wet venting a bottom outlet bidet; a lav vented with AAV wet venting a WC; and a dry vented shower

81796. OK. The bottom fitting labeled "Long sweep 90" is really a combo. Rather than try to use a 3x4 closet bend under the WC, with the resulting two different vertical sections, I'd just use a 3" WC riser from a 3" combo for the cleanout.

81795. Fine, but some of the 3" lines can be 2" and I don't see any upside to making them 3". Specifically, the kitchen branch for the two kitchen sinks; the laundry sink fixture drain; and the washing machine fixture drain.

81797. A problem. When the lav wet vents the bidet, the wye where the drains join is the bidet's vent connection. The bidet trap arm (from the trap outlet to the vent connection) may fall at most one pipe diameter. So no vertical segments between the trap and the wye.

81798. Fine. Same comment on the WC as previously. The tub trap arm is similarly subject to the limitation of a maximum fall of one pipe diameter.

81799. If you have room, a combo is better for the vent takeoff than a san-tee on its back. Either way, the fitting is oriented so that if water backed up into the vent, it would drain out towards the building drain, not towards the shower.

81800. Each kitchen sink will need an AAV. I don't know if the IPC requires a dishwasher air gap; if not, a high loop in the dishwasher discharge is appropriate (the hose rises to just under the counter, then is strictly downhill from there to the wye tailpiece on the sink). If an air gap is required, you drill an extra hole in the counter and install an air gap fitting through it.

81801. I don't follow. If you have a horizontal drain in the crawl space, carrying vented fixtures, and because of intermediate walls you need to jog its elevation, and aren't restricted in horizontal space, use two 45s.

81802. Looks fine. The IPC would be fine with a single 2" roof penetration for the vents, and the individual dry vent takeoffs could all be 1-1/2". If you'd prefer it, you could provide a single 3" branch off the building drain for the laundry tub and washing machine, and you could have a single stack that goes like this from bottom up:

3" cleanout - 3" pipe (or next fitting is street) - 3x2x2 san-tee for the laundry standpipe trap arm - 2" pipe (or next fitting is street) - 2x1-1/2x1-1/2 san-tee for the laundry tub trap arm - 1-1/2" vent.

Or if that order would raise the laundry tub stub-out too high, you could put the 3" cleanout above the two san-tees , which would then have 3" barrels.

Cheers, Wayne

 

[Caryncbreeef]

OK, I'm going to refer to the drawings based on the last 5 digits of the URL. I also am listing them in the order I see them:

81794. Looks fine: a lav vented with AAV wet venting a bottom outlet bidet; a lav vented with AAV wet venting a WC; and a dry vented shower

81796. OK. The bottom fitting labeled "Long sweep 90" is really a combo. Rather than try to use a 3x4 closet bend under the WC, with the resulting two different vertical sections, I'd just use a 3" WC riser from a 3" combo for the cleanout.

81795. Fine, but some of the 3" lines can be 2" and I don't see any upside to making them 3". Specifically, the kitchen branch for the two kitchen sinks; the laundry sink fixture drain; and the washing machine fixture drain.

81797. A problem. When the lav wet vents the bidet, the wye where the drains join is the bidet's vent connection. The bidet trap arm (from the trap outlet to the vent connection) may fall at most one pipe diameter. So no vertical segments between the trap and the wye.

81798. Fine. Same comment on the WC as previously. The tub trap arm is similarly subject to the limitation of a maximum fall of one pipe diameter.

81799. If you have room, a combo is better for the vent takeoff than a san-tee on its back. Either way, the fitting is oriented so that if water backed up into the vent, it would drain out towards the building drain, not towards the shower.

81800. Each kitchen sink will need an AAV. I don't know if the IPC requires a dishwasher air gap; if not, a high loop in the dishwasher discharge is appropriate (the hose rises to just under the counter, then is strictly downhill from there to the wye tailpiece on the sink). If an air gap is required, you drill an extra hole in the counter and install an air gap fitting through it.

81801. I don't follow. If you have a horizontal drain in the crawl space, carrying vented fixtures, and because of intermediate walls you need to jog its elevation, and aren't restricted in horizontal space, use two 45s.

81802. Looks fine. The IPC would be fine with a single 2" roof penetration for the vents, and the individual dry vent takeoffs could all be 1-1/2". If you'd prefer it, you could provide a single 3" branch off the building drain for the laundry tub and washing machine, and you could have a single stack that goes like this from bottom up:

3" cleanout - 3" pipe (or next fitting is street) - 3x2x2 san-tee for the laundry standpipe trap arm - 2" pipe (or next fitting is street) - 2x1-1/2x1-1/2 san-tee for the laundry tub trap arm - 1-1/2" vent.

Or if that order would raise the laundry tub stub-out too high, you could put the 3" cleanout above the two san-tees , which would then have 3" barrels.

Cheers, Wayne

Thanks Wayne. I really appreciate all you effort and time. I will go over this in detail making sure I understand everything. One question to you So you suggest cement board down before rough in? I believe it’s how I’ve done it the past, just been a long time.

 

[wwhitney]

So you suggest cement board down before rough in? I believe it’s how I’ve done it the past, just been a long time.

I don't follow, what cement board?

Wayne