I also found it sold by the bag at Cornelius.

Plants For All Seasons on HWY. 249 carries expanded shale in bags. 281-376-1646

Personally, I would skip all the amending and just do raised beds.

This sounds great and too good to be true. I have been searching for a location to purchase expanded shale here in Houston and I am not having much luck. Any advice?

I would amend the clay to make a flowerbed. Add 3" of expanded shale and 3" of a good quality compost and till that in with the 10-12" of your existing soil. Expanded shale is the best material to use to physically break up the heavy clay. I would then keep the bed mulched and would use a soil activator to promote beneficial microbes.

I have recently moved in to a new build home. As most "new builds" are concerned, the backyard consists of sod and not much in the way of landscaping. I am in the process of removing the sod to put in a planter. I am finding that the large amount of clay below my sod is not going to suffice for plants and I therefore need to begin amending the soil or adding soil. The clay does not absorb much in the way of water and tends to puddle for days after rainfall. Just curious as to what the easiest most successful methods are here. Do I bother amending the clay or should I just dig up as much of the clay as possible to add sand and a local topsoil or compost mix that will allow for a fresh start? This has me so confused.