Does the grass actually turn brown in 2 days, or do the grass blades curl/wilt?

Grass blades wilt or curl in the heat of the day to conserve energy. Its perfectly normal and healthy. If by the next morning they are still curled or wilted, you need to water immediately.

Have you tried running your sprinklers to apply .5in of water, waiting an hour or so to let the clay soak, and then applying the other .5in of water.

You could also try cutting your watering in half. Say .5in twice a week, again letting it soak. .25in wait an hour or so, then the other .25in.

As far as the seaweed, I say yes, use it monthly along with your regular program. There is a lot if info/research out there explaining the benefits, especially for heat stress.

No, they don't actually turn brown in 2 days, just do the wilting thing. But, by the next morning, they are not back.

I recently starting to use the watering method you mention. It goes in three cycles, waiting about an hour in between the cycles. It seems to certainly help. The grass used to look like crap after just 1 day of heat, now I get 2 days :)

So far, I'd say your on the right track. Good advice so far. The deep watering once a week thing works to keep a good rooted lawn good n' rooted, but you got no roots! So you might have to baby it for a while to get those roots down. Use your instincts, and your fingers! Stick your finger in your soil, bout' 3 inches in, is it wet? If not water it, I dont care how long its been, but dont go by the wilting look, like the last post said, grass wilts, its OK.
So how can you get more roots? First find out why you dont have any. Is your OM really low? Is your soil to sandy, or too compact? Did your lawn start as roll out turf, and if so, do you suffer from the dreaded layering?
Have you had a soil test?
Seaweeds a good thing for rooting, Feedback Liquid Compost is better. Anything with micronutrients and natural rooting hormones.

Feed the soil, and the soil feeds the plants.

Mathew Ingles
natural, organic horticulture.
huckfinn49@yahoo.com

Unfortunately, you're not going to get fast root growth in the summer, either (grass is sloughing off its roots and preparing to have a two month nap). Rather than try to hold it during July and spending a fortune on water, maybe you want to let it go to sleep this year until you can fix the issue(s).

This fall, you could also try alfalfa (in addition to seaweed, compost, etc). 20 lbs per thousand square feet will give you lots of micronutrients if you're short on something without overdoing the nitrogen (0.6 lbs/K ft2), and add a lot of organics at the same time to help with water retention (and, one hopes, the soil profile). Alfalfa also contains growth hormones, so you'll really hit all the bases.

You might want to core aerate this fall. If you have the "dreaded layers," (and so many of us do!) it'll help a little bit. I imagine you don't want to dig everything up and amend the soil--I sure wouldn't! If the soil's just too compacted for roots to easily penetrate, that will help it as well.