I just broke up the concrete for a toilet, shower, and lav in my basement. I haven't began to dig out the trenches but did dig up in one small area to see what i was dealing with. Just under the plastic sheating is a pebbly dirt that was wet. Once scoop with my hand and I realized the water table was right there. Serves me right for doing this in the Chicago spring. I'm sure this is fairly normal though. I'd like to understand what I need to consider when digging out the trench and laying the pipe. I figure there will always be water there and it will be hard to dig out consistently, plus it will be a big mess. I figure I'll dry fit everything in the water and then remove from the water to glue it.

1)Any suggestions I should consider? Best practices or tips

2) Plastic sheating- Do i replace the plastic before laying concrete? If it's not sealed to the existing plastic, then what's the point? Is there a way to seal it to the existing plastic?



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I assume this is on the South side, which is where it was most common. If you just have to deal with water, you are lucky. We had to deal with water AND "flowing sand", which meant we had to seal the end of the pipe, dig like crazy to make the trench, put the pipe in the trench and let the sand cover it. Then get the next piece ready, remove the temporary cap, and attach that pipe, etc., until we were done.

It's actually Northwest suburbs. How did you keep the pipe dry to glue?

you have to work fast while you have the water "pulled back".

Is there a way you could first open the floor in another nearby location, drop in a sump pump receptor and pump, and pull the table lower than your working level?

Usually, it would require dropping the water level in the "whole town" unless the pump is right where you are working. In one job, they had well points all around the job site pumping 24/7 to keep the water table manageable.

my son has 3 pumps in his basement.
one on each end and one on the uphill side in the center.

A "puddle sucker" is an attachment for a pump to relieve standing waters, while the ends are being glued to reduce the water/moisture levels to a workable level. But now you know that a mechanical sump system must be in your future plans. Its not something to ignore. Spring time water levels in Cook County can run long into the summer.

Best Wishes