I’m using a 40 to 1 ratio for the foam using seventh Generation dish soap. 1 cup to 2.5 gallons of water. Also 47 pounds of Portland to3.5 gallons of water. For the slurry. But the blocks are brittle and has no strength or structural integrity. Any help would be appreciated and Thank You!
What is your foam weight?
Try using less water per cement - more like 3 gallons in 47 pounds.
For this sized recipe you'll want to add enough foam (90-100 grams per liter) to puff up the mixture to 22 gallons.