In St. George, Utah, we were asked to provide a foundation inspection on a home nearly 95 years old. With a structure of this age, certain issues are expected, and one of the most concerning conditions in this area is elevated sulfate concentration in the soils. Sulfates in soil or groundwater can react with concrete, forming ettringite and gypsum. Over time, these compounds expand, crack, and weaken the concrete, leading to scaling and progressive deterioration. This process appears to have affected the foundation of this home.
We were asked to provide a certification that the foundation could last another 30 to 50 years under current conditions. Given the visible deterioration, that assurance cannot be made. Instead, the engineer recommends replacing the degraded foundation’s structural role with a post-and-beam system. This approach would bypass the weakened concrete and give the home a reliable load-bearing framework for years to come.
Other options were reviewed, such as forming a new concrete wall inside the existing foundation, or attempting to sandblast or wash back the surface to reach “healthy” concrete. Both alternatives carry significant risks—either difficulty of forming and pouring inside the home, or discovering that no sound material remains to build from. For this reason, we recommend the post-and-beam solution as the most practical and dependable path forward. A contractor has been suggested, though the homeowner may choose any qualified builder, and we are available to provide design support if requested.
