Grading And Drainage: "Negative Drainage Conditions"

Real Estate Agent with Top Agents Atlanta Metro

Drainage is one of the biggest problems with foundations and basements here in the south if the grading of water away from the foundation is not correct, it can result in big problems.  This is an excellent article on drainage!!!!

Original content by Jay Markanich 3380-000723

Grading is essential to a house and home inspector reports often say something like, "Negative drainage conditions."

What is a "negative drainage condition?" 


Here is what I say on EVERY report, whether the grading needs attention or not:

"Grading/drainage:  be sure that any surface water or downspout discharge drains easily and well away from the house – a good rule of thumb for soil grading is a slope of 6” in the first 4’ of run away from the house, and 1” of slope for every 4’ of run away from the house thereafter."

Why do I say that on EVERY report?  SO THE CLIENT SEES IT!  I think the report should be educational as well as informational.  And that is GOOD information in anyone's book!

But why?

Certainly this kind of cracking is due to settlement.  The crack is evident on the left just under the vent, and it continues for many feet to the left.  The crack on the right begins at the corner and it continues for many feet to the left.

These are both on the same side of the house.  The house is 45 years old, and has a concrete masonry unit (concrete block) foundation.

I also noticed that the two downspouts on that side of the house had been recently extended to divert gutter water further from the house.  Also, there was soil banked recently against the house.  How did I know this is fresh soil?  Because it was very dark, like out of a bag from the garden center, and a different color from the soil 6' from the house.  IT WAS ADDED RECENTLY.

The key word in both those clues is RECENTLY.  Obviously these sellers had gotten some solid advice from someone about water diversion and "negative drainage conditions."

But the damage had been done.  Years of "negative drainage conditions" had created a foundation problem, about which nothing was done.

My recommendation:  there is a cause and effect when cracking like what is seen above is present on a house.  Sometimes it is obvious and sometimes it requires professional evaluation.  But grading and drainage are so essential to a house, they should always be the belle of the ball when looking at properties.  WATER IS THE KILLER OF HOUSES.  Be sure that water is diverted AWAY from the house.  Be sure...


Jay Markanich Real Estate Inspections, LLC

Based in Bristow, serving all of Northern Virginia

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