Basement Water Issues

[minor4326]

I'm having problems with water seepage into my basement due to poor water management. I have a sidewalk around the house, and my original downspouts went into an under ground tile drainage system. The city blocked access, so now the water has no good place to go. I'm considering putting an extension onto the bottom of the downspout that will go under the sidewalk, then attach to a long underground pipe to carry the water away. I would bury the pipe about 6-10 inches deep, as it starts about 4" deep as a result of having to go under the sidewalk. My concern is freeze-thaw cycles during the winter. During a thaw caused by sun, not necessarily outside temperature, is water from the downspout going to damage the pipes at the bottom 90 degree junction in the ground, or anywhere else along the long route to the opening, due to the pipe being colder, probably below freezing. Am I going to have an ice jam anywhere? Is any damage going to happen by the draining water? I want to use the flex drain 4" irrigation hose. I'm sure schedule 40 would be better, but is it necessary?

 

[LincolnPE]

Yes, you will have the potential to fully realize all the problems you mention by implementing your proposal.

To protect the integrity of the foundation backfill protective zone, downspout extensions should always discharge to the surface a minimum of 5 feet (6 feet preferred) measured perpendicular to the foundation walls. Do not bury them.

The adjacent grade to the foundation should be a minimum of 6" below the top of foundation (8" for residential). The grade should slope at a minimum 10% for 5 feet for remedial purposes of existing buildings (10 feet preferred) measured perpendicular to the foundation walls.