Help with French drains

Specific Inspection Topics Exterior Inspections
1

I am having some back-hoe work done next week. I want them to go around the foundation (about 250 foot) and dig down to about 24 inches with a 8" bucket. I am going this deep because I have a feeling that the house might be sitting on a natural spring. At the end of each line they will dig a hole 3’ x 3’ to be used as dry wells.

My question’ are 1) how would you recommend the placement of gravel? I’m thinking about 3" on the bottom and the put the pipe (covered with fabric filter) and then more gravel to about three inches from top and back fill with dirt.

  1. would you use plastic 4" drain pipe or something stronger due to the weight of the gravel?

I hope I explained this well enough so you can get the idea.

Many thanks in advance for any input.

2

What your thinking about doing isn`t going to help much,if any.
A possible underground spring would still exist. Just my 2 cents.

‘If’ you have some sort of water/moisture intrusion in basement-crawl
you need to first, find how/where the water is getting in and then
fix/repair whatever the problem turns out to be correctly.

Many have exterior cracks,loose-cracked parging and this is where
water/moisture often first enters,would need exterior waterproofing
not a french drain. Some just have x amount of leaky rod holes in
poured walls,these can fix fixed on the inside.

Some have openings/gaps in-around-under basement windows/ledges
or around-under doors and thats where water can also first enter.
Sometimes there are open mortar joints and other times some only
need to snake the lateral line and/or need an adjustment or replace
an existing sump pump.French drain won`t solve these possible problems.

Someone TRIED running underground pipe here,didnt solve anything. Ran from back of house towards front.Weve seen many like this.
http://www2.snapfish.com/slideshow/AlbumID=276723705/PictureID=6950658542/a=122238283_111847456

http://www2.snapfish.com/thumbnailshare/AlbumID=276723705/a=122238283_111847456/

Have done many jobs/homes built along Lake St Clair,was no high water
table problem/hydrostatic pressure problem as many inside co`s often
claim.
Most had problems like this
http://www2.snapfish.com/thumbnailshare/AlbumID=824727013/a=122238283_111847456/

If thats what you choose to do…
Instead of using equipment, you could have it hand dug.
Would be alot less grass etc that gets messed up.
Find/mark any-all underground lines.

At the 2’ depth your talking about,the plastic should be fine.
SEE… ‘Selecting Perf Pipe’
http://www.oxfordplasticsinc.com/perforatedpipe.htm
…‘we do not recommend the use of flex.plastic pipe at depths
GREATER than 1.2 meters’/weight of backfill could collapse pipe

Yep, you could put a few inches of gravel in, then the pipe,then more
gravel.Filter fabric is not going to keep all soil particles outta pipe
regradless of some claims,have pulled many underground piping out
(french drains) that was covered w/fabric-sock-whatever and was either
partially or fully clogged with roots/mud etc. GL

3

Rick, listen to Mark, err…John, he knows what he’s talking about. :smiley: