Can You Install Two Self-Closing Hinges Instead of Three to Save Money?

Published September 6, 2026 • 9 min read • For specifiers, building owners, and contractors

Yes, with one condition: the door weighs 80 lbs or less and stands 6 ft 8 in or shorter. Inside that envelope two Waterson closer hinges carry the leaf and close it reliably. Above it, a 7-ft commercial door moves to three hinges and an 8-ft door to four, because every spring you remove has to be dialed harder to close the same door.

A distributor put the question to us plainly: three closer hinges per door is a harder sell than two, so is two acceptable? The answer below uses Waterson's hinge-count table, the NFPA 80 fire-door rule and a contractor's installed-cost arithmetic. Product context lives on our commercial spring hinges and door closer hinge pages.

The hinge-count table and why height counts as much as weight

The 80 lb / 6 ft 8 in envelope maps to a published Waterson 2-hinge set: A2 mechanical, B2 hydraulic hybrid, or C2/D2 with hold-open. It is a reliability line rather than a pricing tier: above it, each dial sits higher, opening force climbs toward the ADA limit, and the first symptom is a latch miss from a small angle.

Weight is the obvious variable; height is the one that gets skipped. A tall leaf on two hinges leaves the middle third unsupported and prone to bow; a third hinge shares the load and stiffens the leaf, which is why NFPA 80 and most manufacturers converge on roughly one hinge per 30 in of height. See the weight and load calculation guide.

What NFPA 80 requires when the door is fire-rated

NFPA 80 Section 6.1.4 requires a self-closing fire door to close and latch each time it is opened, with a closing mechanism that has no hold-open feature, and Section 6.4.1.4 requires that mechanism to be adjusted so positive latching is achieved on each door operation. NFPA 80 Section 6.4.3 sets the floor for spring hinges: at least two per leaf, the count rising with height (two up to 60 in, one more per additional 30 in), each meeting ANSI/BHMA A156.17 Grade 1. The default listing covers a 3 ft × 7 ft leaf; a larger leaf leans on the manufacturer's listing.

Two closer hinges on a fire door is therefore a code minimum rather than a target; a 7-ft fire door needs three for support, and the practical answer is a 3-hinge Waterson A set. Waterson K51M and K51L are UL Listed self-closing hinges certified to ANSI/BHMA A156.17 Grade 1 and permitted by NFPA 80 on fire door assemblies rated up to 3 hours (UL Certificate GVEV.R26997, 3- and 4-hinge configurations tested). Hold-open (C/D) stays off fire doors. Our fire-door hinge count article walks the full NFPA 80 table; the fire door hinge page covers the listing.

How the set changes with the count

Dropping from three hinges to two changes the system. In a Waterson A3 set (SA, SA, SA1) two hinges carry swing-speed control from 90° to 20° and the SA1 carries latch-speed control from 30° to 10°, the zone where a light door either latches or stalls. B3 (DS, HA, SA) adds a hydraulic hinge, C3 (SB, SA, SA1) adds hold-open at 85° ± 5°, and D3 (DS, HA, SB) combines both. Every set has speed control, mechanical on A and C and hydraulic on B and D.

The cost math a contractor actually cares about

One rule first: Waterson's published application limits require the closer hinge to be the only closing device on the leaf, because two closers on one door fight each other and can damage one or both. The real fork is three closer hinges versus three plain butt hinges plus an overhead closer.

On a door that qualifies for two, the saving is exactly one hinge. On a door that qualifies for three, that same hinge buys the latch-speed control, about 10 minutes of install on the same ANSI/BHMA A156.7 mortise prep, and the latching margin that prevents a second visit. One re-adjustment visit in an occupied building is a billable service call; on a fire door a leaf that stops latching is a written deficiency. The spring hinge vs door closer comparison goes deeper.

The 8-foot, 1-3/4 in door with four hinges: size, count, hold-open

An owner with an 8-ft, 1-3/4 in door on four 4 × 4 hinges asked for a hydraulic version with hold-open and whether the size goes up. Size up: K51M-400 (4 × 4) is a 1-3/8 in door hinge, so a 1-3/4 in door calls for K51M-450 (4.5 × 4.5), and a heavy 8-ft leaf moves to K51M-500 or K51M-500D; expect to enlarge the mortises.

Count stays at four for 8 ft (up to 330 lbs), as an A4 mechanical or B4 hydraulic hybrid set. The UL durability listing covers a 7 ft / 260 lb door; the 8 ft / 300 lb configuration was tested following UL methodology with UL witnessing. Confirm 4-hinge hold-open availability with Waterson; hold-open sets are for non-rated doors only. See the 8-ft interior door page and the 8-foot testing article.

Alternatives considered and where Waterson steps aside

Where Waterson steps aside: heavily gasketed doors, doors that already carry an overhead closer or floor spring, pivot doors, and K51P or W41 hinges on any fire door (neither carries fire certification).

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