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Shaft Wall Systems: Drywall for Elevators, Stairs and Mechanical Chases

How gypsum shaft wall systems work, why they're built from one side, and where San Antonio buildings use them for elevators, stairs and mechanical shafts.

By SCCI Drywall. Published 2026-10-22.

Key Takeaways

• Shaft walls enclose elevators, stairs, ducts and chases with fire-rated construction.
• They're built entirely from one side, because the shaft side often isn't accessible.
• Systems use special metal studs and thick gypsum shaftliner panels.
• The installed wall must match a tested, listed design to keep its rating.

Elevator hoistways, stair enclosures, mechanical chases and duct shafts run vertically through a building. Fire and smoke can travel fast through those openings, so codes typically require them to be enclosed with fire-rated walls. In many buildings, those walls are gypsum shaft wall systems.

Why Shaft Walls Are Different

A normal partition is built from both sides: frame it, then hang drywall on each face. In a shaft, the inside is often an open drop or a cramped space where nobody can safely work. Shaft wall systems are designed to be built entirely from the corridor or room side.

How the System Goes Together

• Track: floor and ceiling track, often a J-shaped track, is fastened to the structure.
• Shaftliner panels: thick, fire-rated gypsum core panels, typically 1 inch, are slid into place facing the shaft.
• Specialty metal studs: C-H, C-T or similar studs hold the edges of the shaftliner panels and are installed as the panels go in.
• Room-side layers: one or more layers of Type X or Type C board are screwed to the studs on the accessible side, then finished.

The result is a fire-rated wall, commonly one or two hours, depending on the listed design.

Where Shaft Walls Are Used

• Elevator hoistways
• Stairwell enclosures
• Mechanical, plumbing and electrical chases
• Duct shafts and trash or linen chutes
• Some horizontal applications, such as rated corridor ceilings

Advantages Over Masonry

• Lighter weight, which reduces structural loads
• Faster installation, especially on upper floors
• Thinner walls, which saves floor area

Details That Keep the Rating

• Every component must match the listed design: studs, panels, board layers and fasteners
• Door frames, elevator entrances and penetrations need rated details and firestopping
• Elevator shafts may face air pressure from moving cars, so stud size and spacing are chosen for that load
• Head-of-wall joints at each floor need a listed joint system. See deflection track and head-of-wall details

Coordination

Shaft walls have to be sequenced with the elevator installer, the mechanical contractor and the fire protection trades. Openings for elevator doors and hall stations, duct penetrations and access doors are all planned before the shaft is closed. See what GCs should expect from a drywall sub.

Shaft Walls in San Antonio

SCCI Drywall installs shaft wall systems, fire-rated assemblies and metal stud framing for commercial and multi-family projects across San Antonio. Call (210) 875-0280.

Frequently Asked Questions

What is a shaft wall?

A fire-rated gypsum wall system built from one side to enclose elevators, stairs, ducts and mechanical chases.

Why are shaft walls built from one side?

The shaft side is often inaccessible or unsafe to work in, so the system is designed to be installed entirely from the room or corridor side.

What fire rating do shaft walls have?

Commonly one or two hours, depending on the listed design and the building code requirements.

Contact SCCI Drywall

SCCI Drywall serves San Antonio and all of South Texas with drywall installation, drywall repair, remodeling, metal stud framing, light gauge framing and acoustical grid ceiling systems for residential and commercial projects.

Phone: (210) 875-0280

Email: sccidrywall@gmail.com

Hours: Monday through Friday, 7:00 AM to 6:00 PM

Request a free drywall quote