Toilet supply line through vanity to avoid exterior wall or floor?
Jeff Cooper| Posted inGeneral Questionson
Given the many reasons to keep plumbing out of exterior walls, such as to minimize penetrations and space taken away from insulation, and the obstacle to cleaning that a toilet supply line coming up through the floor becomes, running a toilet supply line from an interior wall through a vanity seems like a good solution, but I can’t find any accounts of someone doing it, so I wonder whether it poses some problem (other than looking a bit unusual) that I haven’t thought of.
I have a small bathroom laid out like this, with just a bit more than Code-minimum space between the fixtures:
e x t e r i o r w a l l
内墙-虚荣——马桶浴缸内部wall
The vanity will be flush with the interior wall, and its supply and drain lines will run through its left side into that wall. Is there any reason not to run the toilet’s supply line from the interior wall, through the vanity, and out its right side to avoid running it through the floor or an exterior wall?
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Replies
Jeff,
The only complication I can think of would be when you came to change out the vanity sometime down the road.
Where are the water supplies for the vanity going to be? Same spot on the interior wall? If you go that way, think through where the supplies are relative to the drain for the sink, so you can get the vanity into place without cutting huge holes in the side and back.
A couple of alternatives:
- Would it be easier to mount the shut-off valve for the toilet next to the ones for the sink, and run the connection from there?
- You could bring the supply through the floor in the vanity kick-space, and mount the valve on the side close to the floor.
Thank you, Malcolm. The vanity's supply line will come out of the wall on its left inside the kick-space. Both of the alternatives you suggest are good ideas I'll consider.
I see no problem with running it through the vanity
In my current house, they ran the lines for the upstairs bath through the exterior wall, 10 feet.
They made up for this by using r7 fiberglass insulation[!]
Needless to say, it was a problem. It was mitigated since the drains also ran in the same cavity, so getting hot water in the drain freed up the supply.
There are no ceilings, no place to put water lines, so there they remain, now encased in spray foam and cause us no trouble.
The moral of the story[aside from the fact that OC made r 7 fiberglass insulation] is that in a properly insulated wall the pipes are at little risk, and in the case of long term total heat loss, perhaps at less risk than other pipes
As a practical matter, the reason you won't normally see this configuration in new construction is that the supply line is placed as part of the rough plumbing, so it's placed before the tile and vanity are in. It's a workflow thing, you don't want to have to coordinate the plumber with other trades. In renovation things are more free-wheeling and you see stuff like that all the time.
Thank you, Keith and DCC. As I understand it, the plumbing supply rough-in inspection only has to include what will be inaccessible once the walls are finished, and if so, supply lines for the lav and toilet could end in connectable stubs just beyond the edge of the interior wall to the left of the vanity, which would minimize what's in the way of installing the vanity (or replacing it sometime in the future). Making the final connections to the fixtures once the vanity's installed would be easy enough.
Rough-in inspections are typically so that the inspector can see stuff that's going to be covered up later where it will no longer be visible. Think of this as letting the inspector actually inspect things before they get hidden. If you explain what you're planning, I think the inspector will be OK with it. If you don't explain your plan, the inspector might fail you for a missing supply connection for the toilet during the first inspection.
You could use a hole saw and jig saw to make a hole with a slot that would allow the vanity to be pulled out while clearing the toilet line. I've done this many times when I have to fit something around a pipe or wire. Use the hole saw to make a nice, clean hole where the pipe will be with everything in place. Now take a jig saw and cut the two "sides" of the hole straight back to the edge that will be against the wall. This leaves you with a slot back to the wall that has a nice, round end to it. The vanity can now be slid in and out of place without disturbing the pipe, and you can use the piece you cut out to mostly fill the area "behind" the hole to minimize the visual impact of what you did.
Bill
Thank you, Bill. That sounds like the best way to do a slot.