How deep are fescue grass roots?

[ricsin1]

there was a path behind my yard that has been used as a ALLEY WAY for years and the soil has been compacted and is very dusty and dry with a chunks of rock & concrete buried in some sections.... I thought this was a public alley way but a site revealed that this patch of land is mine. I just gained another 7' FEET of backyard space!! I had a guy with a bob cat to come through and break up the dirt & the tire tracks from YEARS worth of cars using the alley way.

now that I gained an additional 7 feet of backyard space I wanted to see what I need to do to extend my fescue over this new area but like i said the soil has been compacted and seems very dusty and dry with a chunks of rock & concrete buried in some sections...i removed as much as i could but that soil seems UNREHABITABLE!!!

the area is 50ft long x 7ft wide...... i can get brand new premium organic top soil dumped on top of this area but i need to know HOW DEEP IT SHOULD BE? how deep does fescue grass roots go?... I may have to sacrifice a small sample section of my fescue to see how deep the roots go?

[RigglePLC]

Freezing and thawing--or in your part of the country--heating and cooling will gradually loosen up the soil. Your plan should work with four inches of topsoil. Naturally, top quality seed should be accompanied by good irrigation and a high quality slow-release fertilizer program. A soil test is in order, but if you want to test only after problms arise that is up to you. In an alley there is a potential for road oil and dust control products applied in past years.