How To Look At A House
McGarry and Madsen's home inspection blog for buyers of
site-built, mobile/manufactured and modular homes
Tuesday, January 5, 2021
The minimum distance from ground to bottom of wood floor joists is 18-inches, and that’s reduced to 12-inches for the bottom of wood beams, per International Residential Code (IRC-317.1.1). This is specified for the purpose of avoiding wood decay that tends to occur when a wood floor structure is too close to damp ground, and not really about having sufficient room to move around under the home. But elevating the floor joists above the ground won’t do any good to protect them against rot if the crawl space is inadequately ventilated. For minimum ventilation standards, go to How much ventilation is required for the under-floor crawl space of a home? Wood that is preservative-treated or a naturally durable species is allowed to be lower to the ground.
Here’s links to a collection of some of our other blog posts about CRAWL SPACES:
Visit our CRAWL SPACES page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.