Site Drainage Question

I could use a little help with a drainage question(s). I am inspecting a house later this week, coming home from another inspection, I was in the neighboorhood, so I decided to drive by and just take a look at the home I will inspect Friday. The lot slops pretty sharply towards the home, and the driveway slops toward the garage area. If I am correct, there should be a 6" slope in 10 FT. 1st question, Is that 6" anywhere in 10Ft. or 6" at 10 FT? Also there is a good chance I am going to have to reccomend further inspection, who should I recommend the buyer contact for this. It is a new home, in a hilly area (common for here) with the grade sloping towards the home. Being new (the Home) I couldn’t tell if there are drainage problems, there are no signs at this time. Is there any special drainage required for this type of home (Sloped Yard).

Do the downhill slopes end at the house without a berm or embankment to divert the water?

If the downhill is toward the front of the garage, does the concrete drive angle off before the garage to divert the water?

Yes the driveway slopes to the left and the yard slops to the right, Which seems to channel the water away from the home. But my worry is in a hard downpoor the water will get to the foundation area, and also may try to enter the garage. I did not get out of my truck for a close look, so I could not see the brick and how the grade is at that area.


In an ideal world the grade should slope 6" in the first 10 feet, away from the foundation.

That being said very few yards are perfect!

Zero lot lines, cut and fill, gutters or absence or neighboring grade/gutters and drainage, landscaping, irrigation techniques, swales, French drains, sub terrain drains and a number of other factors can and will affect the performance of the grading around the structures we inspect.

This one area, around here anyway, redundantly gets the most frequent deficient or defective comments.

Sloped yards generally require swales to keep runoff from impacting the foundation and entering the home.

Amen, that’ll preach.

My own home, if you were to inspect it, would appear that come the next frog-strangler would be under water. Because of the lay of the land, I do not have the luxury of having 6"-8" of slope in that 10 feet. However, I have never had water in the home. I have swales (and they’re not very visible) that divert water quickly and efficiently away. So far…:shock:

Unfortunately, if it is not raining hard while you’re inspecting :smiley: , it is difficult to accurately predict how the water will move. Do your best and use some common-sense. Look for surface drains or any signs that there is an underground network. Heck, ask the builder!

My thoughts, feeble as they may be,

Since this is a “new home” you should refer the client to the building code official who has final say over the final grading in your state.

While a 6" in 10’ drop in grade away from the foundation is a code requirement in Arkansas, it is not a requirement without exception, and swales or other techniques can serve the same purpose.

The Building Code Official who issues the Certificate of Occupancy has final say as to what is and what is not acceptable grade.

And unless you are qualified to challenge the authority having jurisdication, should recognize who’s empowered to make the final call…

I don’t take any chances, as water will get you in trouble more than any other issue, I’m told. Here’s an example of what I often say in my reports.

“Water will be directed toward the house at the XXX instead of away from it, as recommended. This not only allows for the possibility of moisture intrusion but also differential settling, et cetera. Further evaluation by a landscaping or grading specialist is recommended. At a minimum, you should observe the conditions in the crawl space after a period of heavy or prolonged rain prior to the close of escrow.”