Commercial Building Inspector B2Footings and FoundationsEasy
A commercial building inspector is reviewing plans for a wood-framed structure with a crawl space foundation. The plans indicate that the wood sill plates are to be anchored to the concrete foundation wall. What is the minimum nominal diameter of anchor bolts required for this connection, according to IBC Table 2304.3(1), assuming a 1/2-inch bolt is specified?
- A3/4 inch
- B5/8 inch
- C1/2 inch
- D3/8 inch
Show answer & explanationAnswer & explanation
Correct answer: C. 1/2 inch
IBC Table 2304.3(1) (Fastening Schedule) provides minimum requirements for various connections. For anchoring wood sill plates to concrete or masonry foundations, the table specifies a minimum nominal diameter of 1/2 inch anchor bolts.
Why the other options are wrong
- A. This diameter is significantly larger than the minimum code requirement.
- B. While stronger, 5/8 inch is not the minimum required by code for this application.
- D. This diameter is typically too small for foundation sill plate anchorage.
Sill Plate Anchor Bolt Size
The minimum diameter of anchor bolts required to secure a wood sill plate to a concrete or masonry foundation.
- Minimum 1/2 inch nominal diameter.
- Specified in IBC Fastening Schedule.
- Ensures proper connection and resistance to uplift/shear.
Memory trick: Half-inch bolts, a solid hold, keeps the sill plate safe and bold.