For safety, how high must untreated wood floor joists be elevated from the ground in residential structures?

In residential construction, untreated wood floor joists must be elevated at least 18 inches above the ground to ensure safety and prevent issues such as moisture damage and pest infestations. This elevation is a critical requirement in building codes to protect the wood from contact with soil, where moisture can accumulate and lead to rot or decay over time.

Additionally, this height provides access for ventilation and allows for better air circulation, further protecting the structural integrity of the wood. Elevating the floor joists also helps to reduce the risk of termite and insect damage by keeping the wood out of contact with the damp, conducive environment found close to the ground. Therefore, maintaining the 18-inch minimum elevation is a key practice in ensuring the longevity and safety of the building infrastructure.