Custom & Oversized · May 2026
Custom Oversized
Garage Door Spring Cost
RV bays, oversized carriage doors, 18-foot wide three-car bays, and commercial-residential hybrid installations. Spring replacement here is a different category from a standard residential pair, with custom-wound parts and longer labor.
Headline number: $400 to $900 installed for an oversized or custom-spec door. RV bays land at the upper end. 18x8 and 18x7 typically fall in the $475 to $700 range.
Custom-spec pricing derived from HomeAdvisor commercial-residential averages and IDA member quote bands, May 2026.
What "oversized" actually means in spring terms
The garage door industry organises spring inventory around the standard residential size grid. Wire gauges (0.207, 0.225, 0.243, 0.250, 0.273, 0.283), inside diameters (1.75 inch, 2 inch, 2.625 inch), and spring lengths (22 inch through 36 inch in two-inch increments) cover the vast majority of standard doors. Trucks carry the most common combinations. Wholesalers keep the rest in stock for next-day delivery.
Once you exceed the standard size grid (16 feet wide and 8 feet tall is the practical residential ceiling), spring specification leaves the stocked-SKU world. An 18x8 carriage door at 550 pounds needs a pair of 0.283 inch wire torsion springs at 36 inches long. That specification is not on the truck. It is typically wound to order at a regional wholesaler or specialist supplier such as IDC Spring or Service Spring.
Why the door is heavier than you think
An 18 foot wide door is twice the area of a 9 foot wide door, but the weight scales more than linearly because the longer panels need heavier-gauge steel skins and additional reinforcement to resist sag. A production 18x8 insulated steel door from Clopay weighs roughly 500 to 600 pounds. A custom 18x8 wood carriage door from a manufacturer such as Clopay can exceed 800 pounds. The spring system must lift that weight reliably for ten thousand cycles or more.
RV bays at 12x12 or 14x14 fall in a similar weight category, typically 450 to 700 pounds. A 16x12 commercial-residential hybrid (popular for boat storage and home workshops) weighs 700 to 1,000 pounds. All of these configurations need custom-wound springs and a torsion shaft long enough to span the wider opening with a strengthened centre bracket to handle the higher load.
Cost breakdown on an oversized job
Parts on a custom-wound pair: $150 to $350, depending on wire gauge, length, and supplier. Labor: $200 to $400 for the swap including the longer wind cycle and the more careful balance test. Trip and wholesaler run: $50 to $100 if the parts are not in stock. Optional jackshaft opener service: $100 to $200 if the opener needs limit reset and calibration. All-in for an oversized residential job: $400 to $900.
RV bays specifically tend to land at $500 to $850 because the doors are taller (longer travel, longer spring), the openers are usually jackshaft side-mount units that need more careful calibration, and the cable system is longer. Commercial-residential hybrid doors with vertical-lift tracks or high-lift configurations can exceed $1,000 because the spring system includes more hardware (additional drums, longer cables, sometimes auxiliary bearing plates).
Lead-time reality
A 16x7 standard double-car spring failure can usually be repaired the same day. An 18x8 oversized failure usually cannot. The custom-wound springs need two to five business days to arrive. The technician will come out, diagnose, secure the door in the open position (or arrange to leave it open and arrange temporary security if needed), and book a return trip for installation once the parts land. Plan accordingly. If your RV is trapped inside, the contractor can sometimes manually lift the door with two people and a temporary brace, but it is not a long-term solution.
Some specialist suppliers in major metro markets keep partial inventory of the most common oversized sizes (18x8 in particular), which can compress lead time to next-day. Ask your contractor at quote time whether they have a local supplier with stock or whether the springs need to be wound to order. This is usually the single biggest factor in how soon the door is back in service.
Finding the right contractor for oversized work
Not every residential installer is comfortable with oversized doors. The torsion shaft is longer and heavier, the springs store much more energy when wound, and the bearing plates and centre brackets are under correspondingly higher load. An installer who normally works on 9x7 and 16x7 doors can usually handle 18x8, but anything past that benefits from a specialist with commercial-residential experience.
The International Door Association publishes a member directory that filters by commercial-residential capability. Local wholesale suppliers can also recommend installers they regularly supply custom-wound parts to. National franchises sometimes refer oversized work to specialist subcontractors rather than handle it directly.
What to ask before the quote on a custom-spec job
- Are the springs in stock locally or do they need to be wound to order?
- What is the expected lead time for parts?
- What is the wire gauge, length, and inside diameter for my door weight?
- Will you weigh the door before specifying the spring?
- Are the cables and drums correctly sized for the door, or do those also need upgrading?
- What is the warranty on custom-wound springs (usually one to five years, less than stocked SKUs)?
Related cost guides on this site
Frequently Asked
What counts as an oversized garage door?
Anything outside the standard size grid. The standard residential sizes are 7x7, 8x7, 9x7, 16x7, and 16x8. Anything taller than 8 feet, wider than 16 feet, or built to a non-grid width (such as 18 feet or 20 feet for RV storage) qualifies as oversized and almost always uses a custom-wound spring pair.
Why is the price so much higher?
Three reasons. Custom springs are wound to order at the wholesaler rather than pulled from truck stock, which adds parts cost and a lead-time delay. Door weight is much higher (often 500 to 800 pounds for an 18x8), which means heavier wire gauges (0.283 inch and up) at longer lengths. And labor is longer because the heavier hardware takes more time to wind and balance safely.
How long does it take to get custom springs?
Typical lead times from the major wholesalers (Service Spring, IDC Spring, Pacific Garage Door) are two to five business days for a custom-wound pair. Some local supply houses keep partial inventory of common oversized sizes (such as 18x8) and can deliver next-day. For unusual sizes, allow a full week to be safe.
Can a standard installer handle an oversized door, or do I need a specialist?
Most reputable residential installers can handle up to 18x8 with no specialist tooling. For doors larger than that, or for doors with non-standard hardware (jackshaft openers, vertical lift configurations, side-mount torsion), look for a commercial-residential garage door specialist. The IDA (International Door Association) member directory is a good starting point.
Does an RV garage door need a special spring system?
RV doors at 12x12 or 14x14 use a paired torsion system, often with a longer torsion shaft and sometimes with a jackshaft opener mounted to the side rather than overhead. The springs are custom wound to the door weight (typically 400 to 700 pounds) but the principle is the same as any residential torsion install. Spring replacement on an RV door runs $450 to $850 installed in 2026.