Wall hung toilet carrier on exterior wall

[Deathtofishy]

In the planning phase of a bathroom remodel. Looking into possibly installing a wall hung toilet. Both for aesthetics and space saving in a small bathroom.

We live in a climate where our winters average 46° high / 22° low in the winter, but occasionally we will have single digit over nights and negative temps over night once a decade or so. The wall is an exterior wall and initially I thought it was a no-go because of this.

Then I realized that my supply plumbing for the toilet and sink are in that same wall. The house was built in 1956 and the supply lines are the original (will be replaced in the remodel).

I'm trying to figure out how a unpressurized tank holding water (that technically could have some room for expansion) would be more susceptible to freeze failure than pressurized supply lines?

The exterior of the house is brick veneer on wood frame, and below the bathroom is the garage (unconditioned space but still not as cold as outside) with insulation in the floor joists between the ceiling and bathroom floor. The supply plumbing runs in the floor joists under the bathroom floor and up the exterior wall.

There probably is some insulation in the walls, but I'm assuming it's minimal for the time period the house was built.

Any thoughts on this? Maybe there is something I'm not thinking of?

 

[Breplum]

IMO, unless you build out an isolated, insulated wall, you don't want a wall hung assembly subject to freezing. And by the time you add that thickness, you might be back to considering a conventional WC.

 

[Sponsor]

 

[Master Plumber Mark]

you should try building up a couple of wax rings and see if this works...
we have done that before

also that is some really old copper I see on that back wall which scares me

 

[Deathtofishy]

IMO, unless you build out an isolated, insulated wall, you don't want a wall hung assembly subject to freezing. And by the time you add that thickness, you might be back to considering a conventional WC.

I would go conventional before building out an isolated wall. Space saving and aesthetics would be out the window at that point. I may consider furring the wall out a inch or two to get more insulation behind the tank if it would make a difference. A couple 1" rigid foam boards will have just as much r value as a fully insulated 2 x 4 wall with batt insulation.

It's just surpising to me that my exterior wall pipes are perfectly fine, and a larger unpressurized body of water in a plastic tank would not be. Obviously regular heating of the house is probably a factor in why my pipes are fine. But if the heat ever failed long enough in the winter to freeze up the tank, It would seem to me that the water lines would freeze and burst prior being a smaller volume of water and the copper pipes having such high thermal conductivity.

Not arguing at all, just trying to wrap my head around it.

 

[Deathtofishy]

you should try building up a couple of wax rings and see if this works...
we have done that before

also that is some really old copper I see on that back wall which scares me

Guessing this was meant for another thread.

 

[Master Plumber Mark]

No, we have done this before.... and a combination of both the rubber gasket and
the wax rings have worked too...

 

[Deathtofishy]

No, we have done this before.... and a combination of both the rubber gasket and
the wax rings have worked too...

This thread is about an exterior wall mounted toilet, and the potential of it freezing. You also reference photo's and I have not posted any.

 

[Master Plumber Mark]

This thread is about an exterior wall mounted toilet, and the potential of it freezing. You also reference photo's and I have not posted any.

Sorry, i dont know what went wrong...oops

 

[theroot1972]

I just finished a remodel of our master bath and swapped out the conventional closet for a wall hung unit. Much happier! We purchased one that had a straight skirt that hid the s-trap of the toilet and a removable seat. All in all much easier to clean and keep sanitary. Quieter with the tank in the wall as well. The carrier was a bit of a pain as our existing WC was directly under a window but i got it in there. Insofar as your predicament, you’ll have to open up the wall to install a carrier so….why not just add insulation?