What the process looks like, step by step
- Site visit and quote. The installer inspects slab thickness, soil conditions if in-ground, and access. A written quote follows within a few days.
- Permit application. The installer files the permit with the local jurisdiction. Requirements are set at the city or county level.
- Excavation or slab prep. For in-ground units, excavation runs 1 to 2 days depending on soil. For above-ground units, the existing slab is inspected and marked for anchoring.
- Unit delivery and set. The shelter is delivered on a flatbed and set with a crane or forklift. Above-ground units can be hand-walked in when access allows.
- Anchoring and door alignment. Anchors are drilled and set per the manufacturer's documented schedule. The door is aligned and tested for proper latching under load.
- Ventilation, lighting, drainage. Passive vents (and a fan on longer-occupancy units) are installed. In-ground units receive a sump or floor drain. One electrical circuit provides lighting and an outlet.
- County or city inspection. A local inspector verifies the anchor schedule, door operation, and ventilation. Passing inspection is required before final payment.
- Walkthrough and final payment. The installer walks you through door operation, ventilation, and warranty terms. Final payment follows the walkthrough and receipt of documentation.
What you should receive on completion
- ICC 500 test report reference for the installed unit
- Anchoring spec sheet, completed and signed
- Passing inspection record (or scheduled inspection date)
- Written warranty
For the broader decision framework, see our selection guide and 2026 cost ranges.
Frequently Asked Questions
How long does storm shelter installation take?+
An above-ground steel unit installed in a garage typically takes one day. An in-ground steel or concrete unit takes 2 to 5 days depending on soil and drainage. A built-in-place FEMA safe room as an addition runs longer, often 1 to 3 weeks.
Do I need a permit to install a storm shelter?+
In most jurisdictions, yes. Permitting is set at the city or county level. Most installers handle the permit as part of the install. Confirm in writing that the permit is included and who is responsible for the inspection.
Can a shelter be installed in an existing garage slab?+
Yes, for above-ground units, as long as the slab is at least 4 inches of properly cured concrete with appropriate reinforcement. The installer should specify bolt grade and epoxy product. Thinner or cracked slabs may need to be cut and re-poured.
Will installation damage my driveway or yard?+
In-ground installs require excavation and will disturb the area. A reputable installer scopes site restoration in the contract (sod, gravel, concrete patch). Get it in writing before work starts.