Structural · Deck permit before 2015

Deck Lateral Load Anchoring in Decks Built Before 2015

Decks permitted before 2015 may be attached to the house with ledger bolts alone, without the lateral-load anchoring more recent code requires — a factor in most deck collapses.

What it is

In 2015, the residential code (IRC R507) added a requirement that deck ledger boards be anchored against lateral (side-to-side) loads, not just the vertical weight of people standing on the deck — typically met with additional structural screws or tension ties beyond the standard ledger bolts.

Why it matters

Ledger-board failure, the deck pulling away from the house, is involved in the large majority of deck collapses. Decks built to older code were only required to resist vertical load, not the lateral forces from a crowd shifting weight or moving together.

What's worth doing next

A contractor or inspector can check for lateral anchoring (tension ties or additional structural screws) without demoing the deck. If it's original construction from before 2015 with no permit for a later rebuild or retrofit, it's worth having assessed before relying on it for gatherings.

Code changes like these are prospective — they apply to new construction going forward, not retroactively to homes already built. A home that predates a given standard isn't out of compliance with anything; it just predates it. Tarn surfaces this as a consideration worth having evaluated, not a verdict on the home.

See if this applies to a specific address

Enter the year built alongside an address search, and Tarn checks it against this and every other code-era risk factor automatically.

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