Hi and thanks or reading,
I've got a downspout that feeds into a flower bed next to my house. When we moved in a year ago water from the downspout led to some moisture and efflorescence on the concrete block in our basement. A quick fix was to put bendable drain tile on the downspout and redirect the water across a sidewalk and down a slight grade away from the house. Now it's time for the real fix and here is where I need some advice. The sidewalk is 4" thick and about 3'6" wide with an inch or so of crushed rock underneath. I want to route the water under the sidewalk and out to a pop-up near a tree in my front yard. The grade should allow it.

I need to dig under the sidewalk and have read that using a PVC pipe with a water hose will get me through. The drain tile is 4", so how big of PVC pipe should I use to blast the water through?
I also have a pressure washer, should I use that instead? Should I put the drain tile right underneath the sidewalk or go down a few more inches?

I don't want to create a mosquito hatchery so I was thinking of using perforated drain tile however a neighbor warned me that it could heave my sidwalk??? Anyone have experience with this?

How about just plain straight PVC under the side walk part and perforated drain tile for the rest?

Do I need to wrap it in the white fabric wrap that I've see available?

All comments and suggestions are welcome.

Thanks.

 

I used to work for a guy who installed sprinklers & he had a tool that connected to a garden hose for that purpose. It was a pipe an inch thick & about 2 feet long. After I dug on both sides of the walk & under as far as I could go, I would insert the tool with the water running & move it in & out. It would loosen the dirt a little at a time. I guess you could make it happen with the pressure washer & a PVC pipe but don't go more than an inch thick on the PVC.

Your friend is correct about the frost line. Don't use anything perofrated under the walk.

 

My project is done. It took a few hours of work but it worked out well. I was going to use a water jet to dig the whole underneath my sidewalk but decided to try digging from each side first before I got messy. After digging a little over a foot in on each side I had an idea for a tool to dig the rest of the way. I cut a 4 foot section of my 4" PVC pipe and then cut triangular teeth on the end of it. I used this tool to dig the rest of the way under my sidewalk. I would ram it in, turn, and pull out. I dug right through in about a half hour and not much mess. To finish the project I put pea gravel under the sections of the pipe that had holes. I used 4inch straight PVC with no drain holes in it under the sidewalk (to avoid any frost heaves of the sidewalk) and then transitioned to 4" sewer pipe (allows the water to drain out and not become a mosquito hatcher), which is identical to 4" solid PVC except that it has 3 half inch holes on the bottom of it spaced every foot or so. I wrapped the sewer pipe section in a fiber mesh designed to keep crud from entering the pipe and then installed the pop up and buried everything. I used a level to make sure I had a grade all along the pipe. So far it is working great. I need to install a filter (probably a metal mesh or plastic grate) in between where the downspout comes down and the 4" piping starts. Right now not much gets into my gutters but in a few years when my trees are taller it will be a different story.