Under Slab Gravel & Under Slab Insulation
Using insulation under the basement slab is another way of making the home more energy efficient. The most common R values for under-slab insulation are R-10 and R-15. Installing gravel under slab in high water table is highly recommended. It allows the water to move to the drains and out of the house before rising above the basement slab. It also is beneficial in radon mitigation.