Back porch plumbing

Before we get to finishing the porch top, let’s take a step back and look at the very bottom. I still have some underground plumbing to finish so that we eventually can pour the concrete floor at the basement level.

A large part of the underground plumbing was already finished. We had removed the old grease trap with the temporary connections last year and connected the sump discharge to the sewer line. More recently, I extended the sewer line past the new back porch footing and took care of the footing drains.

Floor drains

The cast iron soil pipe (CISP) work that was left to do were two floor drains and their respective vents.


Yes, you read right – two floor drains! One won’t cut it and here is why: First, there is the centrally located, or general floor drain. If water spills into the back porch basement level, this floor drain should pick it up.


The second floor drain is located toward the east end and has two functions.

  1. It should pick up liquid from a future composting toilet if we chose to install one. There are a variety of composting toilets on the market. Some are self contained and others rely on a processing tank. Those with a processing tank may require a drain for small amounts of liquid discharge.
  2. It should allow me to drain and winterize the water system in the yard. We plan on an underground cistern that feeds several faucets throughout the yard with the collected rainwater. I don’t plan to install the plumbing system that connects the cistern with the faucets below the frost depth. Instead, the system has a low point at the back porch from which I can drain it, and thus winterize it.


Raising the sump

If I want to pour the concrete floor in the back porch basement level, I have to raise the sump. in other words, the sump basin rim has to be at the same elevation as the planned concrete floor.

No problem. I knew that I had to raise the sump by six inches, so I got myself two three inch concrete adjustment rings and mortared them atop of the existing sump pit.

Last but not least, I extended the future sump discharge to the planned cistern through the sleeve I provided in the foundation wall.

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About Marcus de la fleur

Marcus is a Registered Landscape Architect with a horticultural degree from the School of Horticulture at the Royal Botanic Gardens, Kew, and a Masters in Landscape Architecture from the University of Sheffield, UK. He developed a landscape based sustainable pilot project at 168 Elm Ave. in 2002, and has expanded his skill set to building science. Starting in 2009, Marcus applied the newly acquired expertise to the deep energy retrofit of his 100+ year old home in Chicago.

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