I misspoke earlier. I strongly believe that sand is not a good amendment for clay soils. The particles are simply too small. As long as you add lots of organic matter with all of that sand you purchased, you might get away with it. Sand can work only if you actually remove clay and replace it with sand. Otherwise, those little particles will pack up with the clay particles. (Unless you add lots of OM, too.) Soil aggregation is created by the microorganisms. You aren't going to achieve it any other way. They will survive ONLY in a soil that has the organic content to support them. Beneficial fungi and bacteria are what a good soil consistency is all about. Yes, organic amendments eventually decompose and are turned into microbe and plant body, but the addition of a continual supply of OM is not difficult or challenging. In a planting bed, this may mean an annual application of organic mulch of some kind. BTW, some organic fibers take years and years to decompose, so continue to provide texture to the soil. On your lawn, it means that you let your clippings return to the soil when you mow. A healthy stand of turf returns a huge amount of OM to the soil just in the form of root sloughing (as mentioned earlier). Now, about that gypsum! If it were only true! Well, actually, the miracle IS true in some cases. If you live in an area where your soil is sodic (excess sodium), and the lack of soil aggregation is BECAUSE of that, gypsum will help. The chemical reaction of the CaSO4 takes the sodium out of commission, so to speak. But if your soil is just plain clayey....it won't do a thing, other than add calcium and sulphur to the soil. Thus, the gypsum miracle is not a total myth, lol! If you have naturally sodic soils, you'll find that annual applications of gypsum will help (along with everything else). I have brick hard clay soil. With very little initial improvements, I find that plants of all kinds thrive in it, as does the lawn. Here is a link that might be useful: See if this makes sense.....

For the next 2.5 months you need to take what you get. Any seed planted now, especially adjacent to a driveway, will die. Tender new roots cannot survive a normal summer heat. This means you will have some weeds come in to fill up the bare spots. Just tolerate those weeds until fall when you can take care of them and reseed. Hard soil is not a good reason to add topsoil; however, low spots are a good reason for topsoil. Sounds like you're doing that okay. If you do add topsoil, use your feet to stamp it down before you put the seed on. Stamping it down will reveal where the low spots are going to be and you can add more topsoil right then and there. Stamp that down, too, to make sure you have enough soil. Then apply your seed on top of that...and stamp down the seed. That is all you need to do when starting with new topsoil. As you probably know from your quotes around your mom's comment, you don't need to mix up the soil to aerate it. Mother Nature does not have animals roaming around mixing up the soil to aerate it. She has animals going around stomping on the soil and pressing seed down into the surface. Your seed mix might have had some Kentucky bluegrass in it. Check the Guaranteed Analysis printed on the side of the bag. Kentucky bluegrass takes 3 weeks to sprout once in the ground and kept moist. There is a slim chance that some of that has germinated and a further slim chance that some of it will survive the summer. Kentucky bluegrass is the type of grass which spreads to fill in bare spots. The other type of grass in your mix is likely a type of fescue. Fescue is a "bunch grass" which grows in tight little clumps. It can spread but only by enlarging itself. If you want to have a dense coverage, you either need lots of fescue seeds or 10% or so of Kentucky bluegrass seeds. One secret you need to know is that fescue seed sprouts in 2 weeks while the KBG takes a week longer. What often happens is people will see the new grass coming in and back off on the daily watering. This leaves the KBG at a stage where it was almost ready to sprout and then it dries out. KBG requires full sun, so if this spot is under a tree or between buildings/fences, then the fescue would be your only choice of seed in your area. Here are the basics of lawn care for mature grass. You can practice these principles on the rest of your lawn. For now your new seeds need water more frequently because of the shallow roots and new growth. Water deeply and infrequently. Deeply means at least an hour in every zone, all at once. Infrequently means monthly during the cool months and no more than weekly during the hottest part of summer. If your grass looks dry before the month/week is up, water longer next time. Deep watering grows deep, drought resistant roots. Infrequent watering allows the top layer of soil to dry completely which kills off many shallow rooted weeds. Mulch mow at the highest setting on your mower. Most grasses are the most dense when mowed tall. Bermuda, centipede, and bent grasses are the most dense when mowed at the lowest setting on your mower. Dense grass shades out weeds and uses less water when tall. Dense grass feeds the deep roots you're developing in 1 above. Fertilize regularly. I fertilize 4 times per year using organic fertilizer. Which fertilizer you use is much less important than numbers 1 and 2 above.

Re: the rehab and what I did right or wrong.... 1) I would not install sod next time in the first place. I would get the exact seed that I want and call in a hydro-seeder. 2) Really make sure to scalp the lawn. I mean cut it really short! Nothing taller than 1/2". Anything taller than that and it mats down under the top dressing which means the seed won't take because the grass underneath creates an air pocket that kills the new grass, but KBG doesn't grow through like some of the warm season grasses. 3) With KBG I'd do it in May if I had a choice. There are going to be weed problems whenever you expose fertile soil, but it is manageable. Forget about the weed issues because there is an easy solution there with KBG. But KBG takes a LONG time to come in from seed. The one thing that doesn't help is if it starts to get cold before it really starts growing well. IOW, if you wait till Sept to avoid some of the weeds and it starts to drop below 50*F in Oct, it'll be till late next spring before things start to look good again. The important issues with KBG are moisture and soil temp. May/June is best IMO. 4) Do it all in one shot! If there are low spots that will require more than the suggested 1/4" top dressing, just go ahead and fill them in. Don't wait! Have your preferred seed on hand and get that thing level the first time. This work is too strenuous to be doing it more than once. Little touch-ups later are to be expected, but get it 90% done in the first shot. 5) Anything more than 4,000sf you should try to locate a mechanical spreader for the top dressing and drag the lute or chain link around with a lawn tractor. 6) This is a point of debate, but... Currently the Orbit sprinkler heads are much better than the Rainbirds. Make sure that your sprinklers are exactly how you want them before doing anything with the lawn. And yes, sand isn't great for them, but it is pretty easy to fix. There are probably more that I'll include later.

Start with a good, reliable soil test. Contact your local OSU Cooperative Extension Service office for assistance about this. They will send your samples to either Penn State or the University of Kentucky since the soil testing lab at the university has been closed, but the results you get will be good. This soil test will tell you about your soils pH (for a lawn that should be in the 6.0 to 7.0 range) and the levels of Phosphorus, Potash, Calcium, and Magnesium. Then you can dig in with these simple soil tests, 1) Soil test for organic matter. From that soil sample put enough of the rest to make a 4 inch level in a clear 1 quart jar, with a tight fitting lid. Fill that jar with water and replace the lid, tightly. Shake the jar vigorously and then let it stand for 24 hours. Your soil will settle out according to soil particle size and weight. For example, a good loam will have about 1-3/4 inch (about 45%) of sand on the bottom. about 1 inch (about 25%) of silt next, about 1 inch (25%) of clay above that, and about 1/4 inch (about 5%) of organic matter on the top. 2) Drainage. Dig a hole 1 foot square and 1 foot deep and fill that with water. After that water drains away refill the hole with more water and time how long it takes that to drain away. Anything less than 2 hours and your soil drains� too quickly and needs more organic matter to slow that drainage down. Anything over 6 hours and the soil drains too slowly and needs lots of organic matter to speed it up. 3) Tilth. Take a handful of your slightly damp soil and squeeze it tightly. When the pressure is released the soil should hold together in that clump, but when poked with a finger that clump should fall apart. 4) Smell. What does your soil smell like? A pleasant, rich earthy odor? Putrid, offensive, repugnant odor? The more organic matter in your soil the more active the soil bacteria will be and the nicer your soil will smell. 5) Life. How many earthworms per shovel full were there? 5 or more indicates a pretty healthy soil. Fewer than 5, according to the Natural Resources Conservation Service, indicates a soil that is not healthy. to see what else your soil might need to become a good healthy soil that will grow strong and healthy plants. Once you know what the soil you have is now then you can begin to plant what you will need to do.