FLJeff
New Member
Hello,
I am just finishing the tear-down phase of a master bath remodel. This bathroom had a tiled alcove shower and a toilet. Just outside the door (to the right in the photos) is a double vanity. The house is slab-on-grade.
I have a bit of a problem with the new DWV layout.
The existing 2" shower drain is only 16" from the wet wall. It is a bit odd in that it has no trap directly under the drain. It disappears under some inaccessible slab so there may be a running trap under there. It then takes a 90-degree right turn and expands to 3" with a vented tee. Almost immediately afterward, the toilet drain intersects with a wye and the 3" drain continues under the wall behind the double vanity. The double vanity has a drain and vent for each sink that presumably drain into this line. The first vent/drain stack from the vanity is only about 18" from the right wall in the photo. All of the vents are 2".
The new toilet drain is to be about 4" to the right of where the existing vent penetrates the slab (in-wall toilet).
The new shower drain is to be centered in the 5'x3' shower alcove space.
The vent cannot be within 16" on either side of the new toilet drain due to the in-wall toilet frame (and framing). I cannot easily move it to the left because the wall becomes an outside wall right where the insulation begins. The slab also gets thicker just to the left of the existing vent. I would really like to avoid having to break this section of the slab. Thankfully this wet wall is not load bearing.
My current plan is to abandon the existing inaccessible shower drain pipe. I will move the vent to the right by 24" to leave room for the in-wall toilet framing. The shower drain will run diagonally from the center of the square-ish cutout across where the existing toilet flange is and join the drain line with a wye.
The problem is that this configuration makes my shower arm about 66" from shower drain center to the vent. Based on what I have read, I have seen 2" trap arm maximum distances ranging from 60" to 96". Florida's building code specifies 8'. Will I be safe from trap siphoning with this long trap arm?
Because the vent is coming down the wall, I can't vent the shower drain line until it joins with the under-wall line. This means I have to either vent this line after the toilet and either just before or just after the shower line joins it. All of these fittings will be quite close to one another, so I am not sure how much the order matters. Is there such a fitting as a wye with a vent port on top to vent it right at the intersection? Is it OK to have the toilet draining past the shower?
I am open to suggestions if there is a better way. Worst case, I could break up more of the slab and sole plate to move the vent leftward. I really don't mind doing the extra work if my lazier solution could possibly cause trouble.
Thank you.
I am just finishing the tear-down phase of a master bath remodel. This bathroom had a tiled alcove shower and a toilet. Just outside the door (to the right in the photos) is a double vanity. The house is slab-on-grade.
I have a bit of a problem with the new DWV layout.
The existing 2" shower drain is only 16" from the wet wall. It is a bit odd in that it has no trap directly under the drain. It disappears under some inaccessible slab so there may be a running trap under there. It then takes a 90-degree right turn and expands to 3" with a vented tee. Almost immediately afterward, the toilet drain intersects with a wye and the 3" drain continues under the wall behind the double vanity. The double vanity has a drain and vent for each sink that presumably drain into this line. The first vent/drain stack from the vanity is only about 18" from the right wall in the photo. All of the vents are 2".
The new toilet drain is to be about 4" to the right of where the existing vent penetrates the slab (in-wall toilet).
The new shower drain is to be centered in the 5'x3' shower alcove space.
The vent cannot be within 16" on either side of the new toilet drain due to the in-wall toilet frame (and framing). I cannot easily move it to the left because the wall becomes an outside wall right where the insulation begins. The slab also gets thicker just to the left of the existing vent. I would really like to avoid having to break this section of the slab. Thankfully this wet wall is not load bearing.
My current plan is to abandon the existing inaccessible shower drain pipe. I will move the vent to the right by 24" to leave room for the in-wall toilet framing. The shower drain will run diagonally from the center of the square-ish cutout across where the existing toilet flange is and join the drain line with a wye.
The problem is that this configuration makes my shower arm about 66" from shower drain center to the vent. Based on what I have read, I have seen 2" trap arm maximum distances ranging from 60" to 96". Florida's building code specifies 8'. Will I be safe from trap siphoning with this long trap arm?
Because the vent is coming down the wall, I can't vent the shower drain line until it joins with the under-wall line. This means I have to either vent this line after the toilet and either just before or just after the shower line joins it. All of these fittings will be quite close to one another, so I am not sure how much the order matters. Is there such a fitting as a wye with a vent port on top to vent it right at the intersection? Is it OK to have the toilet draining past the shower?
I am open to suggestions if there is a better way. Worst case, I could break up more of the slab and sole plate to move the vent leftward. I really don't mind doing the extra work if my lazier solution could possibly cause trouble.
Thank you.