Install & Anchoring
Anchoring
Also known as: anchor schedule, shelter anchoring, tie-down
What an anchor schedule includes
- Bolt size and grade (e.g., 1/2 inch Grade 5)
- Minimum embed depth into concrete (typically 3 to 5 inches)
- Spacing along the shelter perimeter
- Epoxy or mechanical anchor product (e.g., Hilti HIT-RE 500)
- Slab thickness and concrete strength minimums (typically 3,500 psi)
Why anchoring fails
Three common failure modes: anchors set in a slab that is too thin or too weak, epoxy not allowed to cure to spec, and substituted hardware that does not match the test report. Each one breaks the chain from wind load to foundation that the shelter was tested with.
Distinguished from
- Tie-down
- Tie-downs are surface straps, used for mobile homes. Storm shelter anchoring engages the concrete with structural bolts and is not interchangeable.
Practical example
An installer arrives with a quote that specifies '1/2 inch wedge anchors, 8 per shelter.' The producer's documentation requires '5/8 inch threaded rod set in HIT-RE 500 epoxy, 12 per shelter, 4 inch embed.' That mismatch should stop the install until the schedule matches.
Authority: ICC 500, manufacturer installation instructions. Last reviewed 2026-06-04.
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