Question
Hi there - thanks so much for taking my question.

We're going to be obtaining some quotes to regrade our home (we've had some drainage issues that have cause some dampness and water in the basement).  Some people that we've spoken with have seemed to infer that it's not a large project - just throw some top soil on and slope it properly.  While my research online indicates it's a much more involved process - removing all the topsoil and sloping with a high clay content soil, then replacing all the topsoil on top.

We haven't had the companies over yet for the quotes, but I wanted to make sure I understood the right way to do things so I could ask the right questions.

So my question is not only about the soil, but also about the foundation plantings.  We had planned to (sometime in the future) remove all the overgrown plantings we currently have and re-landscape, but are not sure we're ready for that financially.  Is it best to have the foundation free of plantings to regrade properly?  We can do it if need be - we just won't replant extensively and will probably be weeding a lot for the next few seasons as there won't be many plants!!

The last question, assuming regrading is best done with the clay soil, is about the amount of topsoil that is usually placed on the clay.  I really enjoy gardening and prefer deep soil - what's the 'usual' amount of topsoil that is used?  Is there any drawback to adding a few more inches than the norm?

Thanks again for your time!
Maggie

Answer
Well I think you already know the answer to the first question. If the top soil is loose the rain just penetrates it to the clay layer and then runs in the direction of the slope of the top of the clay layer. So it is perhaps important that the clay layer slopes correctly. Second yes it would probably be best to remove plants to get the best slope and remove old roots that might possibly have become channels for water. Top soil is usually 3-4' deep. But the more the better. You can till 3-4" to the top 6" of clay to make a good planting mix. There is no harm in adding more top soil. Be sure to mulch it all well when complete. Also just keep in mind simply sloping the soil may not be enough. Consider gutters, splash guards, downspouts, etc. Tie down spouts into drain lines and pipe them away from the house. You may also need to re-waterproof the foundation walls which is a major job requiring excavation around the house.

Best of Luck

Sean J Murphy
Please check out my websites at http://www.seanjmurphy.com
and http://www.amenityarchitects.com