Size / 18x7 oversize
18x7 oversize garage door install cost in 2026
The 18-foot wide oversize is the standard for three-car garages with a single long door, workshop spaces, and any house with a large pickup or RV. Replacement labour in May 2026 runs $400 to $700 on existing tracks. RV-height variants (18x8, 18x10) and full-view glass push the labour into the $700 to $1,800 band. This page covers the labour line items only.
Labour by scenario, 18x7 and wider
| Scenario | Low | High | Time | Crew |
|---|---|---|---|---|
| 18x7 replacement on existing tracks | $400 | $700 | 5 to 7 hours | 2 people |
| 18x8 RV-clearance replacement | $500 | $900 | 5 to 7 hours | 2 people |
| 18x10 RV-clearance replacement | $700 | $1,400 | 6 to 8 hours | 2 people |
| Full-view 18x7 (glass-and-aluminum) | $900 | $1,800 | 1 day | 3 people |
| New construction 18-foot opening | $1,200 | $2,800 | 2 to 3 days | 2 people plus framer |
2026 US national averages. Oversize doors above 18 feet usually require an engineer-stamped header for new construction. As of May 2026.
Section 02 / Three-car single span
When the 18x7 makes sense versus two 9x7 singles or a 16x7 plus a 9x7
A three-car garage can be specified three ways. Three separate 9x7 singles is the most common, with a center load-bearing wall between the singles. A 16x7 double plus a 9x7 single (with a load-bearing wall between them) is cleaner-looking and quite popular in newer construction. A single 18x7 spanning a wider opening is the least common because it sacrifices the structural division between bays.
Single 18x7 spans are most useful for workshop garages where you want unobstructed access for a long item like a boat trailer, a fifth-wheel hitch, or a workshop bench layout. They are also common on RV-storage garages where the height matters more than the width division. From a labour cost standpoint, a single 18x7 replacement is cheaper than installing two doors in the same 18-foot span (one trip, one mobilisation, one disposal run).
The structural decision is where 18x7 gets expensive. A 16-foot span is the conventional header beam limit in residential framing, and many builders use a doubled 2x12 LVL header without engineering. An 18-foot span typically pushes the header into engineered glulam or steel beam territory, and that requires an engineer stamp on the permit drawings. The header itself costs $400 to $1,200 more than a conventional doubled LVL, and the engineering fee adds $300 to $700.
All of which is to say: the labour line on the door is $400 to $700, but the project cost on a fresh 18-foot opening is significantly higher because of the framing. If you are buying an existing house with an 18-foot opening already there, you only pay the door-replacement labour.
Section 03 / RV clearance
RV-storage garages and the height premium
If you are storing a Class A or Class C motorhome, the standard 7-foot door height is not enough. Class A motorhomes typically clear at 12 to 13 feet, fifth-wheel trailers at 12 to 13 feet, and travel trailers at 11 to 13 feet. A practical RV garage uses an 18x10 or 18x12 door, and the install cost reflects the additional panel count and the longer torsion tube.
An 18x10 needs six panels rather than four, so the install adds 30 to 45 minutes of panel-stacking time. The torsion tube is two feet longer, the springs are gauged for a heavier door, and the tracks have an additional vertical track segment. None of this is exotic, but it stacks. Expect 18x10 RV-clearance install labour at $700 to $1,400, compared to $400 to $700 for the same width at 7 feet tall.
Opener choice matters more on RV doors. The vertical lift travel is significantly longer, and standard belt-drive openers may not have enough rail length without an extension kit. Many RV-garage installers default to a jackshaft (wall-mount) opener at this scale, which avoids the rail issue entirely and is also quieter for an attached living space.
Section 04 / Why dual torsion is standard
The 18x7 torsion-spring system
At 16x7, some installers will spec a single torsion spring (heavier gauge) and some will spec dual counter-wound springs. At 18x7 and wider, every reputable installer specs dual springs as a matter of safety. The reason is that single-spring failure on a wide door can be violent because the panel weight has to go somewhere, and the dual-spring design fails gracefully (one spring still bearing load) where a single-spring failure can drop the door.
Winding two torsion springs adds 30 to 45 minutes of crew time over a single-spring winding. The hardware cost difference between single and dual is roughly $40 to $80 in spring stock, but the labour difference is real. Most installers will quote the dual-spring rate by default on an 18x7 and not offer the single-spring option even if you ask. That is the right call. Take the dual-spring spec.
The torsion-spring service life on an 18-foot door is roughly 15,000 to 20,000 cycles for a standard-gauge installation, with high-cycle variants (28,000 to 50,000 cycles) available at a $50 to $100 hardware upcharge. If you use the door more than four times a day on average, the high-cycle spec is worth the premium because the second spring set will outlast the door itself.
For details on what happens when a spring fails and what spring replacement on an oversize door costs separately, see our sister site at GarageDoorSpringReplacementCost.com.