Drainage around a slab

[Guidshir]

I have a new metal building where the slab is on a slope, not a huge slope, but at the back of the slab (the high side) the slope cuts directly down to the slap and creates a low point.
I think I need a drain box buried around the center point (in the image) with pipe buried to lead the run off around the slab and to the low point.

The slope to the back of the slab is fairly steep where it was cut into the hill and I don't think I can ditch or swale to get all the water away.

I'm looking for opinions about how to go about this. It would be as simple as a buried 4" corrugated pie in one direction starting at a drain box covered with gravel and having a ditch leading to the box.

 

[RNeumann]

Bummer- typically their is 3-4’ minimum of slope away from a structure. Without fixing the grade first I don’t see how one drain box is going to solve the issue.

 

[CalG]

I have a new metal building where the slab is on a slope, not a huge slope, but at the back of the slab (the high side) the slope cuts directly down to the slap and creates a low point.
I think I need a drain box buried around the center point (in the image) with pipe buried to lead the run off around the slab and to the low point.

The slope to the back of the slab is fairly steep where it was cut into the hill and I don't think I can ditch or swale to get all the water away.

I'm looking for opinions about how to go about this. It would be as simple as a buried 4" corrugated pie in one direction starting at a drain box covered with gravel and having a ditch leading to the box.

Get a post hole digger.

Drill a bunch of deep holes where ever you feel more drainage is needed.
Fill the holes with 2 inch stone . Top with landscaping cloth and put a plant pot over each.

Hey! It's a tractor forum. You get a tractor solution.

Myself, I work out the drainage before the slab is poured.

 

[kevin37b]

Get some fill in there and grade it !

 

[fishheadbob]

Water runs downhill. Duh. I think your idea of some 4 inch tile should do it as long as your tile trench has a little pitch to keep the water flowing until it reaches some sort of outlet. I'm a big fan of wrapping drain tile in geotextile or even good landscape fabric to keep the tile from silting up and plugging. You could probably get away without the collection box, but I don't know how much water you get there.

 

[Pawatch]

Do you have spouting on your building? You could direct the water with down spouts.

 

[jaxs]

I would go uphill to redirect course for most water so that it's flowing on either side when it reach's building. Downed pine trees layed at angle are ideal because as they rot away, they nurture developing berms. The ditch required for small amount that reach's wall would be easy to do.

 

[plowhog]

I'm surprised there is not more distance between the top of the slab and nearby grade. It looks to only be a few inches. Does the edge of the slab have a footing?

 

[hslogger]

Me, myself and I, would just put a full curtain drain in with an exit to a french drain further away. Spendy, yeah, but the right way is the right way. Shoot the slopes and leave the worry. Corrugated pipe and round river rock do the job correctly.

 

[Guidshir]

The slab has a full footer. The slope behind it is probably 30 degrees, so I will probably try to cut it a little steeper and put in a ditch a foot out from the back wall to create the downgrade on that side and then put a collector box in the center of that ditch/low point with the connected divertor pipe being perforated to collect water from the soil. That with some work on the top to divert as best as possible will probably do the trick. It's not a tall slope, maybe only 12-16 feet.