Question
James,
We have a acre lot where we just built a home, grass,weeds, are all pretty much gone from the building process.  We are now left with a lot of hard clay soil.  What is the most economical way to grow grass?  Is it true we have to put 2-3" of top soil on the clay first?  
Any advice you may have would be greatly appreciated.  As top soil is expensive here. (wisconsin)

Answer
Hi Rene, You want to avoid layers of different textured soil. You just need to loosen the clay from the compaction caused by equipment around the house.  Till the whole area 6" deep.  Any organic matter you can till in (leaves, grass clippings, fine bark) will help keep it loose for good root development.  If you can't add organic matter, sow a really heavy stand of annual ryegrass on the area.  Once it's a few inches high, till it again. Then sow your desired grass at the appropriate time.  Check your pH.  It should be 6 to 6.5 for most turf grasses.  
Go to your local garden center and ask for either liquid or granular humates.  Apply it 2-3 times per year.  It will significantly help your soil microbes and improve you soil quickly.  Jim