DFM Concrete Construction Inc. has released a new advisory aimed at helping Central Valley homeowners avoid costly foundation failures as the region embraces an accelerated wave of Accessory Dwelling Unit (ADU) development under Assembly Bill 1033. The company warns that expansive clay soils — common throughout the Valley — can expose homeowners to repair bills ranging from $5,000 to $15,000 if not properly addressed during construction.
The guidance arrives as Stanislaus County introduces seven new pre-approved ADU designs, making it easier and more affordable for residents to add small housing units to their properties. But despite these streamlined permitting tools, DFM Concrete says the region’s soil challenges remain a significant risk that can undermine even well-designed projects.
“The Central Valley is known for expansive clay soils, which swell during wet winters and shrink during dry summers,” said Ruben Mendoza, founder of DFM Concrete Construction Inc. “This movement can affect standard concrete slabs if not properly engineered. We are releasing this information to ensure homeowners understand that a foundation is the most critical structural component of their new investment.”
Key Steps to Preventing Foundation Failures
The company outlines three essential actions homeowners should take before starting any ADU project in 2025:
1. Conduct a Soil Evaluation
DFM urges property owners to have the soil professionally tested before purchasing plans or pursuing a permit. Homes built on expansive clay or in flood zones may require raised foundations or concrete piers instead of standard slab foundations, which can fail under shifting soil pressure.
2. Avoid Cutting Corners on Structural Materials
According to the guidance, many low-cost bids reduce rebar density or concrete quality — decisions that can lead to cracks, settlement, or even long-term structural failure. DFM notes that “cheap” bids often produce the very foundation problems that later cost homeowners thousands to repair.
3. Verify Who Oversees the Work
The company emphasizes that homeowners should confirm who will be present each day during construction. Direct supervision, they say, is crucial to ensure proper concrete placement and to avoid mistakes that only become visible months or years later.
Aligning With California’s Push for More Housing
The advisory also aims to support California’s statewide push for more accessible housing by pairing state incentives with careful engineering. Stanislaus County’s free pre-approved plans help residents save time and money, but DFM argues that proper foundation work is necessary to protect those savings in the long term.
“We specialize in structural integrity, specifically crawl space foundations and piers, which are often necessary to combat soil movement,” Mendoza said. “Our goal is to ensure the initial pour is the only one the client ever needs.”
About the Company
Founded in 2023 by veteran contractor Ruben Mendoza, DFM Concrete Construction Inc. serves nine counties across the Central Valley, including Stanislaus, Merced, and San Joaquin. The company focuses on structural foundations for both residential and commercial projects, ranging from slabs to piers to crawl spaces, with an emphasis on long-term durability, safety, and transparency.
The new advisory marks their latest effort to educate homeowners amid rising interest in ADUs and shifting property owner expectations under California’s evolving housing legislation.
Originally reported by DFM Concrete Foundation in WFLA.
