Does a small home sitting on piers really need to be tied down?

Yes. HUD's installation standards require manufactured homes to be secured against wind with an anchoring system or by connecting the home to a foundation designed to resist those forces. Piers carry weight downward but do little to stop a home from sliding or lifting in high wind. FEMA's guide traces many past failures to poorly attached anchors, materials that rusted, homes not fastened to their piers, and badly attached straps, some installed by homeowners. A FEMA fact sheet says anchors and tie-downs keep a home stable in high winds and floods. Even a heavy steel home can be pushed by wind, so plan anchors that suit your site's wind zone and soil.

Check your local rule. This varies by state, county or city. Your permitting office has the final word; the official lookup pages below show you who that is.

Sources

• 24 CFR Part 3285, Model Manufactured Home Installation Standards (2020 edition)U.S. Government Publishing Office (HUD regulation)
• FEMA P-85, Protecting Manufactured Homes from Floods and Other HazardsFEMA
• Protect Your Manufactured Home from Flooding and Wind (FEMA DR-4884 fact sheet)West Virginia Emergency Management Division / FEMA