7 to 10 days. To check lift the sod up. If you can lift it, no roots.

Please let us know how the products work. Anything the keeps people from rototilling is already a great product in my book.

And tell us where you live. Sunset zones are only slightly better than the USDA hardiness zones. Neither one is of any value with lawn issues. Your real location is the only thing that helps.

If you know about Sunset zones, you probably have the Sunset Western Garden Book. Read the part about installing new lawns and you'll see they don't recommend rototilling. At least my SWGB from 1970 does not. Can't imagine they would have changed their mind on that.

OMG! It Worked!! After 2 weeks, it was well rooted, and growing! So I went around scraping up what St. Augustine sod I could find in stock at my local nurseries. I guess I added about 130sf. That was one week ago today, and it is doing well also!
I am in Van Nuys California. My yard was just dirt, I don't think I could even call it soil. An inch deep layer of puffy dust, (that the dogs LOVE bringing in the house), on top of hard clay. Not even a weed in sight.
The prep I did was rake up stray leaves, and then spray the Penmax. After it dried, I added 1/4 inch layer of Turfmax and slapped down the sod. We had a pretty good heatwave, so I watered 2-3 times a day.
I will likely do the rest of the yard in the spring when St. Augustine is more readily available.
WOO HOO!

The soil softness test is to take a screwdriver and see how deep you can stick it into the soil. With hard soil it might not penetrate at all. With really soft soil you might get as much as a 36-inch rod to go down.

I'm very glad the Penmax worked for you. At the risk of really bursting your bubble, Penmax's active ingredient is a non-ionic surfactant called Poly(oxy-1,2-ethanedial) as well as many other names. It is very similar to the ingredients used in food preparation to keep the food moist. It is also used in shampoo and other household cleaners. Rather than paying $100 per gallon for a product like Penmax, for the past 6 months or so we have been talking about using shampoo itself to soften soil. Most shampoos have anionic surfactants. Baby shampoos have nonionic surfactants. Both seem to work equally well as long as there are no conditioners in the shampoo. My last shampoo purchase was Alberto Vo5 for a dollar a bottle. A 15-ounce bottle will cover 5,000 square feet.

There is no research that supports or disclaims the affect of surficants and changes in soil characteristics. The bottom line is what results occur to the quality of the turf. I have had mixed results using surficants and at best, minimal. Nothing approaching conclusive. I have observed significant improvement in turf after aeration.
Neither seems to give continueing/permenet results.
Curently I am experimenting with adding calcium to reduce "compaction"/soil hardness. We'll see.

Wouldn't shampoo kill beneficial bugs and worms?
I'll try the screw driver test and let you know.