What size overhead door do I need for a box truck or fleet van?
Go 12 feet wide by 12 feet tall for a standard box truck, 10x10 for high-roof cargo vans, and 14x14 if a semi trailer will ever back inside. The rule that saves buildings: measure your tallest vehicle including roof-mounted equipment, then add at least 12 inches of height clearance and 2 feet of width beyond the mirrors.
Vehicle-by-vehicle sizing chart
| Vehicle | Typical overall height | Recommended door |
|---|---|---|
| Transit/ProMaster high roof | 9'0"–9'6" | 10' w x 10' h |
| 16'–20' box truck (non-CDL) | 11'6"–12'6" | 12' w x 12' h |
| 26' box truck | 12'6"–13'6" | 12' w x 14' h |
| Semi with 13'6" trailer | 13'6" | 14' w x 14' h |
| Bucket truck / service crane | varies, often 12'+ | measure boom stowed, add 18" |
Heights above are real-world with clearance lights, refrigeration units, and roof caps, which is why the sticker height on the spec sheet is not the number to build around. We have replaced more than one header in Yukon and Mustang shops after a rented 26-footer met a 12-foot opening at 5 mph.
The clearances beyond the opening
Door size is only half the sizing job. Before you order, check:
- Headroom above the opening: a standard-lift sectional needs 12 to 15 inches; low-headroom hardware squeezes into 9. Rolling steel needs room for the coil, roughly 24 to 34 inches depending on curtain height.
- Backroom depth: a 14-foot-tall sectional runs horizontal track about 15 feet into the building. If your bays are short, high-lift or vertical-lift track keeps the door out of the way, a common setup in truck shops along the I-35 corridor.
- Approach grade: a sloped apron effectively raises the vehicle at the header. On steep approaches in older OKC industrial parks we spec an extra 6 inches of door height.
- Operator choice: tall doors with high-lift track pair with jackshaft operators rather than trolleys. Our answer on commercial operator types covers the difference.
What fleet-sized doors cost in the OKC metro
Installed pricing scales with size, insulation, wind rating, and track style: an uninsulated 12x12 commercial sectional sits at the budget end, insulated versions for conditioned fleet shops cost more, and a 14x14 wind-rated door with high-lift track and a jackshaft operator tops the range. Cutting a larger opening into an existing wall adds structural work, so a free on-site measure through our installation team is worth scheduling before you commit to a truck purchase, not after.
If you are enlarging an opening in a steel building, read our companion answer on doors for metal buildings first, and browse the full commercial lineup for wind-load and insulation options. Financing is available on full installations.
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Related Questions
How often do fire-rated doors need a drop test?+
Every year, under NFPA 80, and after any repair to the door or its closing system. Each test needs a written record signed by a qualified technician, which fire marshals in the OKC metro routinely request. Read the full answer →
What garage doors work best on steel and metal buildings?+
Ribbed steel sectionals and rolling sheet doors are the standard picks, but success depends on reinforcing the opening: metal building girts need added jamb framing to carry track and spring loads safely. Read the full answer →
Why is my commercial roll-up door so hard to lift?+
Lost spring tension inside the barrel is the usual cause, followed by dry or damaged guides dragging on the curtain. Barrel springs are under serious load, so retensioning is a technician job, not a ladder-and-wrench job. Read the full answer →
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Related answers
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