Construction & DIY How thick should a concrete slab be for a water tank? March 10, 2026 by Tanp | Leave a Comment The ideal thickness for a concrete slab supporting a water tank depends on several factors, including the tank’s size, weight, the type of soil beneath it, and local building codes. Generally, a slab thickness of 6 to 8 inches is recommended for most residential water tanks, but larger or heavier tanks may require a thicker […] Read more ยป