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I’m installing a new bathroom, and was told that the soil piping should not be sloped too steeply. Apparently the water tends to bypass the soil which then sticks to the pipe when the slope is too great, says my partially informed source. Reducing the slope will be a pain.
Can some of you experienced plumbers address this issue? What is an acceptable range of slope for the closet arm and soil line? Or is this whole notion some kind of myth? Of course, the installation will be a new, low-flow toilet.
Thanks.
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It should either be a drop of 1/4" per foot, or a drop greater than 1 foot per foot (45 degree angle or better). Between those is the bad place where the liquids do indeed run past the solids and leave them stranded to stick to the pipes. At less than 1/4" per foot, stuff can just sit where it is. Remember with the low flow toilet to flush 2 - 5 times for solids. Do what it takes to get this right, or it'll be a pain in the a** for the life of the plumbing.
-- J.S.
*the slope should be 1/4 inch per foot. They will let you get by with between 1/8 and 1/4 but it really needs to be 1/4. They will not pass it if more. If you do it without appoval they will make you tear it out. To get the right slope just add more riser. They made me raise my whole foundation a foot just to get the right slope. Around here you need a certifate of occupancy to get the power turned on, and these people control it.
*Easiest thing to do is make like stair steps. Go 1/4 inch per foot for whatever distance you can. Then make a vertical drop. Then resume the 1/4 inch. Repeat as many times as necessary.
*I would take Tom's avice with a small change. Instead of vertical drops use 45's and make 45 degree offsets between runs. Easier to clean with a snake if it ever needs it. Keep in mind the code requirements for cleanouts, etc.
*I agree with Wet Head, but keep it as simple as possible. Keep the number of transitions to a minimum, and it never hurts to have more cleanouts than code requires.-- J.S.
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I'm installing a new bathroom, and was told that the soil piping should not be sloped too steeply. Apparently the water tends to bypass the soil which then sticks to the pipe when the slope is too great, says my partially informed source. Reducing the slope will be a pain.
Can some of you experienced plumbers address this issue? What is an acceptable range of slope for the closet arm and soil line? Or is this whole notion some kind of myth? Of course, the installation will be a new, low-flow toilet.
Thanks.