Dish Soap and Soils

[sal a]

Anyone have experience with adding dish soap to water for moisture conditioning expansive clay soil? According to a contractor, this was recommended by a geotechnical engineer on another project. It helps the water permeate into impermeable soils. I am wondering if there are any adverse effects to the soil strength.
Any input is appreciated.
Sal

 

[Ron]

Yes, it has some merit. It helps to reduce the surface tension of water and lubricate the soil particles. It works similar to sodium hexametaphosphate (Calgon) to flocculate clays when you're doing a hydrometer test in the lab.