Drainage question

[KrucksGarage]

I'm about ready to install my gutter drainage and infiltration pit and have to cross the front of the garage with one of the ground pipes to get one corner over to the pit. My question is how deep should I go and what is the ideal material to be driven over for an in-ground drain? I may have dump trucks and other heavy equipment in and out of the garage so I want to be sure I won't crush it. Ferguson waterworks in my area sells schedule 40 and schedule 80 in 4" drain pipe I believe. All of my materials will probably come from there.

Thanks!

 

[6768rogues]

PVC will stand quite a bit of weight if fully bedded. If you plan to drive dump trucks and heavy equipment over it, incase it in concrete. We did at the public school for pipes crossing the driveway where all the buses go.

 

[KrucksGarage]

PVC will stand quite a bit of weight if fully bedded. If you plan to drive dump trucks and heavy equipment over it, incase it in concrete. We did at the public school for pipes crossing the driveway where all the buses go.

Yea I guess that's an option too, although I'd rather stay away from the permanence of concrete if I can in this application. My lot is all sand here, do you think there's a depth I could go with a heavier pipe and be safe being bedded in sand?

 

[ptgarcia]

I would recommend ductile iron or similar across the drive area, and schedule 80 PVC where not subject to heavy vehicle loads.

 

[Radix2]

How deep can you go? Usually you are stuck with the height of your outflow and the pipe grade back from there?

What is your soil like? What will your driveway be?

Here we have sand, and sch40 at any reasonable depth (12+) is fine.

If you look at the various engineering references (for ex. - http://www.jmeagle.com/sites/default/files/TB06DepthofBurialforPVC.pdf ) even thinwall SDR35 pipe is good for 20ton truck traffic at 1 foot depth.

so I am sticking with 12in.

 

[Radix2]

I would recommend ductile iron or similar across the drive area, and schedule 80 PVC where not subject to heavy vehicle loads.

come on man - based on what?

 

[KrucksGarage]

How deep can you go? Usually you are stuck with the height of your outflow and the pipe grade back from there?

What is your soil like? What will your driveway be?

Here we have sand, and sch40 at any reasonable depth (12+) is fine.

If you look at the various engineering references (for ex. - http://www.jmeagle.com/sites/default/files/TB06DepthofBurialforPVC.pdf ) even thinwall SDR35 pipe is good for 20ton truck traffic at 1 foot depth.

so I am sticking with 12in.

I can pretty much go as deep as I need to in this area, there's nothing else in the way. My lot is sloped and the i-pit is down hill a ways from the front of the building.

The soil is extremely sandy, my build thread in my signature starts out with some digging photos of you're interested in checking that out. Super sandy in this area. Makes for easy digging but makes a few other projects and gardening a challenge.

The driveway is crushed asphalt for now, possibly concrete in the future but who knows if I'll get that far. It sounds like from your input that I'll be in pretty good shape at one foot down, maybe I'll buffer up to two feet and even consider bumping to schedule 80. I'd be plenty stout at that point. It's actually not too bad of a cost increase only for that 60' run to go from sch. 40 to sch. 80.

I sure appreciate the input guys!

 

[zkdiesel]

2’ coverage and pvc will be fine. At 3’ Plastic tile pipe won’t crush as long as properly installed with no overdig
Here’s an 8” plastic we put in at 8’ coverage. Average coverage is 2’-3.5’

How far you guys depends on your outlet and mainting fall so you don’t get buildup in pipe. If you have sandy soil and are using perferated you need a sock and more fall, as sand is technically rock and won’t wash out like dirt....

 

[KrucksGarage]

2’ coverage and pvc will be fine. At 3’ Plastic tile pipe won’t crush as long as properly installed with no overdig
Here’s an 8” plastic we put in at 8’ coverage. Average coverage is 2’-3.5’

How far you guys depends on your outlet and mainting fall so you don’t get buildup in pipe. If you have sandy soil and are using perferated you need a sock and more fall, as sand is technically rock and won’t wash out like dirt....

Thanks for the info. Given the information from a few of you guys, I think I'll be in good shape.

 

[ptgarcia]

come on man - based on what?

My 20+ years civil engineering experience.

 

[Bretny]

If you have sandy soil why not just drain to air? If your trying to keep water away from the foundation then a trench with clay in the bottom.

 

[mz44]

Sch40 will work, I would say minimum 18", 2' should be plenty. Backfill with stone if you can, just make sure to "chock" material (stone or dirt) around the pipe and compact good. Compaction is the key, use a jumping jack, not a plate tamper. If you compact the material sufficiently the pipe will not be able to move and should be fine.

 

[GarageGuy89]

Around here ADS N-12 is cheap and rated at 12" cover for asphalt, less cover if doing concrete. They will stand behind that if I am not mistaken.

PVC cracks, whereas the N12 poly pipe will bend/squish. Most places only stock the crappy corrugated N12 product so people go with PVC.

Typically 24" of cover is industry standard for minimum cover. Anything less and your pushing the envelope. Less than 12" warrants ductile iron pipe. As with everything else in construction, your foundation or bedding is key. improper bedding will make the pipe carry the entire load.