I’m trying to size a floor joist system to completely hide a 3″ solid waste line that originates at a toilet and drops across the width of the room at 1/8′ per foot. To be able to calculate the necessary depth of the floor I need to know how far close to the top (or bottom) of the subfloor the bend in the pipe can be. In other words: Generally speaking, how far down from the top of the subfloor is the centerline of the horizontal pipe at the top of its run? How far down would this be if it was an 4″ pipe? Are there special bends for these kind of limited-height circumstances? What is this bend called? Any help is greatly appreciated.
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Hi Michael,
A drop of 1/8' per foot is too much. Perhaps you meant an eighth of an inch, but either way I figure you can calculate how much drop you'll get since you didn't say how far the run is.
a standard 3" 90 degree elbow is about 6 1/2" from the top to bottom, so that's about where you'll be starting below the toilet assuming you glue the elbow tight to the top of the underside of the subfloor. I don't know of anything made for the purpose that is shallower but I'm not a plumber so maybe it exists.
Basically the thing is called a closet bend, but I usually associate that with cast iron.
Not much help,
Dog
That's right, my bad. I meant to say an 1/8" per foot. Thanks for the info. Nice to know the term.
best is to consult your plumber.
My guy will go to copper if need be for the run if it's easier/cheaper than chopping up framing.
lotsa different ways of getting there...a good plumber will know how to fit in in.
JeffBuck Construction Pittsburgh,PA
Fine Carpentery.....While U Waite
Michael
Available in ABS or PVC with Metal or Plastic
adjustable rings.
Provides unlimited offset when used in conjunction with a Hub x Hub 45º Elbow.
When used with a Spg x Hub 45º Elbow it provides a 2½" offset and the most shallow flange and bend combination available.
Available in 4" x 3" and 4" x 4" sizes.
Isn't it generally a better idea to avoid a long horizontal run between the closet bend and the soil stack? There being no vent until you get to the stack, I'd guess that momentum in that run would be likely to cause a siphon and suck the toilet trap out -- especially if some of what gets flushed tends to form a "piston" within the pipe.
-- J.S.