Question
Hi, I need to raise the ground level around the foundation of my house, about 6-8", so that rain water flows away from the house. It is regular grass lawn at the foundation. What is the best soil/loam/sand to use? Is the any better season(s) in which to do it? I live in the north east & near the sea.Thanks, Gregg

Answer
Hello,

The only weather restrictions on working with soil are frozen ground and overly wet ground. For the grass to do well you cannot have too much clay or sand. Clay would produce a semi permeable surface that would promote water running off the surface and sand would produce a permeable soil. However,grass does best in loam and would not do well in a highly clay or sandy soil. I would try to obtain the maximum clay content possible that would still permit the grass to grow. Certain plants,some with a grasslike appearance, and some ornamental grasses tolerate clay soil. I would aim to make the clay content near 50 percent.

If you want to keep loam soil next to the foundation then consider placing a clay layer under the loam.

Sloping the ground will not prevent all water from seeping around the foundation and if you experience further drainage problems after you slope the ground,you may need to install subsurface drainage.

Other methods are to use are plastic sheeting to keep water from entering the soil around the foundation,the use of a concrete apron around the foundation and the use of underground clay caps and gravel fill. A footing drain is usually necessary. This is a perforated drain pipe or some other channel that carries water away from the foundation. Of course the water must discharge into an outlet of some kind or soak into the ground away from the foundation.
Good luck. Let me know if I can be of further help.

Mark Harshman
http://www.mahdrafting.com
Email: [email protected]

http://www.allexperts.com/ep/724-104627/Landscaping-Design/Mark.htm