Can you post a picture of the layers? Roots should not be on top of the soil, but you may be describing thatch. I don't think tilling is a good idea because it can be tough to get things level after tilling (even though you get it level, it then settles and is not level after settling). It can also bring up lots of weed seeds.

If you're looking at thatch, you probably want to get rid of it or use a slit seeder to break through it to ensure you get good seed to soil contact.

What kind of grass did you have before and what kind are you going to plant? Do you mulch mow? At what height? How often do you water and how much water do you put don when you do water?

Here's a picture of what I now believe is indeed a thick layer of thatch. We've been in the house about 3 years - not sure what the builder originally seeded with, though I'm sure it was junk. I've tried to aerate, top dress with compost, and overseed a couple times with a TTTF blend. But, the surface is so bumpy and I had weeds galore, which is why I decided to start over from scratch.

I do mulch mow at the highest setting. I've also got soil test results from VA Tech. The only thing that was low was Nitrogen - everything else was good.

I'd like to create a level bed of decent soil that will support a healthy lawn. I'm willing to do the work required, either by hand or I also have a Mantis tiller.
I'm thinking I need to strip off that thatch layer. But then what's next?

Again, thanks.

Here is a link that might be useful:

That looks like thatch to me. It's a pretty thick layer, so it may interfere with the ability of water to penetrate. You should probably do something to get rid of it or break it up, either dethatching or core aerating with multiple passes to really break things up (and make sure it's set so that the cores are pulled pretty deep or it won't get into the soil.

Don't worry about the low N in your results, N is often not even tested because it is transient in the soil. That just means that you need to fertilize periodically.

If I were you, I'd avoid tilling unless you can get it graded afterward. Tilling may end up making it even more uneven once it starts to settle.

If your soil is really compact and water doesn't penetrate well, you can help that by increasing the organic content. Mulch mowing is a good starting point.

If you have a Starbucks near you, you can get free coffee grounds from them and spread them directly on the lawn. They're a mild fertilizer (around 2% N) and also a good source of organic matter. You don't need to worry about getting them exactly even. They won't cause growth spurts or burning like synthetic fertilizers.

Once you reseed, water often enough to keep the seeds and surface of the soil damp. You don't need the water to penetrate deep into the soil yet because the grass doesn't have any roots to speak of.

Once the grass gets going well, work on watering more deeply and less often. If water runs off too soon, you can try watering in cycles. Water in one spot until the water is just about to run off, then switch to another. Keep going around the yard doing that. When you finish, return to the first place. If it hasn't been an hour since you stopped watering there, wait until the hour is up and repeat the process.

David Hall (he posts here and on other lawn forums) uses a soaker hose to help soften soil. He hooks up the soaker hose and turns the water on a trickle and lets it run in one spot for a week. He then moves the hose to the next spot and repeats it. I think it may take several rounds to get it to work (I haven't done this, so I'm going by what others have reported). From what I've read, it works by encouraging fungal growth in the soil.

Thanks, bpgreen. I appreciate your time and insight.

I live in VA and have the same problem.

I'm rounding up, tilling to 4-6" and then getting topsoil delivered to put on top to a depth of 2" all around. I've got a bobcat rented to spread the soil and a a roller ready to go to flatten it all out so grading should be covered.

If you are going to till your soil, don't bother with a mantis or hand tiller. Rent a rear-tine tiller. you have compaction similar to what I had and even with the monster 8hp tiller I rented (~350 lbs piece of equipment) it took 3 passes to till everything nicely to a depth of 4-6".

good luck!