Tile depth and installation methods

5030tinkerer · Mar 2, 2009

I have a need to provide about 2000' of drainage for my Iowa cornfield. Any recommendations for depth? I'm thinking that I need to go down only as deep as necessary to avoid damage from heavy equipment if it's wet out and something drives over - maybe 18 inches down?

Also, is the suggested method simply a 4" perforated plastic tile with a sock directly buried or is that just a waste of time and I should be looking to encase the trench with landscape fabric, use corragated pipe at the bottom (sock covering optional), 1" or so clean rock on top of that up to maybe a 9" depth, cover the whole thing with the exposed tips of landscape fabric overlapped over the rock, and then put a 9" covering of dirt over the whole thing?

framer · Mar 3, 2009

I would use 6" perforated tile with sock but cover with gravel about foot.
Socks will plug eventual.I would go with 20" to 24" depth.Framer

5030tinkerer · Mar 3, 2009

Thanks for the guidance. When you say that you would cover the sock-covered tile with 12" of gravel, are you just putting this gravel directly over the tile and then backfilling over that or are you protecting the gravel from dirt infiltration somehow?

bigtiller · Mar 3, 2009

I installed field tile for 2 years in the 80's when i was laid off from my regular job. I was just a laborer, not the owner. The only time we ever used a sock was in a 200 foot long sandy area at the end of the line where it dumped into a pond.

For depth, 18" would be a minimum. 3' is ideal because water will work it's way to it from a further distance over the first few years.

For size, 4" is better than nothing but 5" is pretty much standard. We ran 200' of 4" once because that was what the farmer wanted. He had a 6" that was pluged and wanted to connect a 4" to it above the plug and dump in a different area. We told him it would blow out and the following spring it did. If your 2000 foot is a single run then that would be OK but if there will be some laterals connecting to a trunk line then it may be better to start with a 6" trunk line and drop down to 5" for the laterals. If the area is really wet then 6" all the way may be best. Your local installer will know what is best for your area and type of ground.

framer · Mar 3, 2009

Yes we use sand or gravel over drain tiles in ks. clay plugs socks up.Tile is
used inside and outside basement walls drain to sump pumps.Dirt over top
Framer

5030tinkerer · Mar 3, 2009

I never heard that clay plugs socks up. Interesting. It looks like I'll be installing 6" tile without a sock in a bed of 1" or so limestone without a sock or landscape fabric around it. I never, ever would have thought that. Any other ideas?

rambler · Mar 4, 2009

We just drop the tile in the trench & close it up again, perf plastic tile. If you have a low spot, a load of good sand from the sand pit in that spot will help it drain out quicker.

Depth depends on your topography, but should not be less than 24 inches to the _top_ of the tile if any possible way to help it, and going about 3 feet deep is ideal for drainage. Going 4 feet deep will give you better field, but often costs more.

Going only 18 inches deep would crush the tile, not let it drain very much, and be _very_ easy to hit with a ripper or other deeper tillage tool. Not good.

I would run 5 or 6 inch tile for that length, but 4 inch probably would work fine if it has some fall to it & if you place it deep enough to get your soil drained out.

Anything you say will work out, except going only 18 inches deep - that is the big red flag I see. Go deep, do yourself some good!

You gotta get it ok'ed with the FSA/USDA offices first, that can take a few months. Good luck.

--->Paul