Here is some pictures of a portion of a building drain in the middle of a 4 unit condominium building in Canton, MI. The entire underground had
to be dug up and replaced due to back pitched piping causing accumulation of grease and waste, resulting in continuous flooding in the basements.
It all starts off innocently enough. The drain backs up, but it goes back down. The the drain backs up, but this time someone needs to snake
it out with a sewer cleaning machine. Then it keeps backing up, repeatedly on a regular basis. People are getting upset, and here comes the
sewer camera with the pipe location equipment. The news...not good. The pipe needs to be dug up and replaced.
So how did this happen? When the building is first being built, the plumbers are down below in the mud installing a maze of piping for the
sanitary and storm systems. But two factors become a problem. If the building sewer is not brought into the building low enough, the we quickly
have elevation issues. Meaning, the pipe as it travels further into the building is rising slightly for pitch. Each 10 feet of piping is rising
2.5" (typically), and before long the top of the pipe is not clearing the footings. The footings in the building shown in the pictures below
are located around the entire perimeter and also at each poured basement wall that joins the neighbors unit. The width of this footing was
24 ". We can now see the dilemma, where the plumbers miscalculated their rise in pipe and at each footing, forced the pipe under the footing
and creating a belly or back pitched section of piping.
But wait, lets give those new construction plumbers credit! They are no doubt highly skilled, hard workers, and extremely fast! The other scenario
could be, that sometime between the pipe being installed, and the cement being poured, the basements get swamped out with water from rain and
loosens the soil that the pipe is in and allowing the piping to rise or float in the water. If this happens, the end result is multiple back
pitched locations in the piping, giving a roller coaster effect.
Whatever the cause, the pipe comes out and nice new pipe comes in. This project utilized a Hilti electric cement saw with a Hilti vacuum dust
control machine, thus allowing the cement to be removed with minimal cement dust for the people currently living in their homes.