Types of Steel Ladders in Buildings and Structures

The main types of steel ladders in buildings and structures are vertical fixed ladders mounted to a wall or frame, caged fixed ladders, fixed ladders with a rail or cable safety system, inclined ship ladders, roof hatch ladders, pit and sump ladders, and access ladders on tanks, towers and chimneys. Which one fits depends on how high the climb is, how often people use it, what they carry, and which rules apply to the building. In Ontario, workplace ladders follow the Occupational Health and Safety Act regulations, and roof access ladders also have to meet the Building Code's anchorage standard.

This guide sorts the types by where they are used and what each one is good for. For the numbers (rung spacing, width, clearances), see steel ladder dimensions and specifications.

Steel ladder types at a glance

Fixed ladders: wall mounted, caged and with safety systems

Wall-mounted vertical ladders

The basic steel access ladder is two side rails with welded rungs, held off a wall or structure by brackets. Ontario's Industrial Establishments regulation (Reg. 851, s. 18) requires a fixed access ladder to be vertical, with rungs at least 15 cm from the wall and side rails extending 90 cm above the landing. Wall-mounted ladders suit low climbs and occasional use: a roof over a one-storey unit, a mezzanine storage area, a mechanical platform.

Exterior wall-mounted ladders on commercial buildings often get a lockable climb guard or door at the base to keep the public off the roof. That is an owner's choice, not a code requirement, and it has to be shown on the drawings so it doesn't block the climb when open.

Caged ladders

Where a fixed ladder extends more than 5 m above the grade, floor or landing, the Ontario regulations call for a safety cage starting no more than 2.2 m above the base and continuing at least 90 cm above the top landing, plus rest platforms at intervals of not more than 9 m with the ladder offset at each one. Our post on fixed steel ladders with cages in Ontario covers these rules in detail.

Ladders with a rail or cable safety system

On towers, water tanks, chimneys and similar structures, a ladder fitted with a safety device that protects a worker who falls is exempt from parts of the Ontario ladder rules. The device is usually a rigid rail or a cable fixed along the ladder, with a sliding fall arrester connected to the climber's harness. The ladder steel has to be designed for the arrest loads, and the system has to be compatible with the harness and arrester. In the United States, OSHA now requires these systems (or personal fall arrest) on new fixed ladders over 24 ft, which is why many manufactured ladders are sold with them.

Inclined ladders: ship ladders and alternating tread devices

A ship ladder sits between a fixed ladder and a stair. It is inclined rather than vertical, has flat treads instead of rungs, and has handrails on both sides. Users usually climb it facing the treads. Ship ladders are popular for equipment platforms and mezzanines where there isn't room for a stair, and they make it easier to carry a small tool bag than a vertical ladder.

An alternating tread device is a related product with half-width treads that alternate left and right, letting it run steeper than a ship ladder in a narrow space.

Neither is a stair under the building code. Whether one is acceptable depends on what it serves: a ship ladder to a rooftop unit is a different question from a ship ladder serving a storage mezzanine that people use every day. Reg. 851 also says that where frequent access is needed to elevated equipment, permanent platforms must be provided and reached by a fixed stair or a fixed access ladder. Check with the designer and the building department before choosing an inclined ladder over a stair. If a stair will fit, it is usually the better answer for daily use; see industrial steel stairs and roof access stairs.

Roof access and parapet ladders

Roof access is the most common job for a steel ladder on a commercial or industrial building. There are three usual arrangements:

• Interior ladder to a roof hatch. Under Article 3.2.5.3. of the 2024 OBC, a building over 3 storeys with a roof sloped less than 1 in 4 needs access to the main roof areas, by a stair or by a hatch at least 550 mm by 900 mm with a fixed ladder. The ladder is set so the climber clears the hatch frame, and side rails or grab bars continue through the opening.
• Exterior wall ladder over a parapet. The ladder climbs the wall, and the side rails either flare apart so the climber walks through them onto the roof, or continue straight up so the climber steps off sideways. A short ladder or step on the roof side may be needed where the roof is lower than the parapet.
• Roof-to-roof ladders between levels of a stepped roof.

For any fixed ladder that provides access to a roof, Article 3.6.1.6. of the 2024 OBC requires the attachment and anchorage to follow Supplementary Standard SB-8. That standard covers design loads, safety factors, minimum anchor size and maximum attachment spacing, so the brackets are a designed part of the ladder rather than an afterthought.

Pit, tank, tower and chimney ladders

Pit, sump and vault ladders give access below grade: elevator pits, sump pits, valve chambers and utility vaults. They live in wet, sometimes corrosive conditions, so galvanized steel or stainless steel is normal. Some are cast into the concrete wall; others are bolted to it after the pour, which needs anchors suited to the exposure. For cast-in items, see our post on embed plates.

Tank, silo and tower ladders are usually tall, exposed and fitted with rest platforms, cages or safety systems. The ladder brackets attach to a shell or frame that may not be designed for them, so the structure's designer needs to confirm the attachment.

Chimney ladders have their own line in the code. Article 6.3.3.4. of the 2024 OBC says that where access ladders are provided for chimneys, they consist of steel or bronze rungs built into the chimney walls, and that rungs for external ladders begin at least 2.5 m above ground level.

Fire escape ladders in Ontario

People search for "steel ladder fire escape" expecting a ladder bolted to the side of a building. In Ontario, that isn't what the code allows for a fire escape. Under Subsection 3.4.7. of the 2024 OBC:

• fire escapes may not be erected on a building except on existing buildings where providing other exit facilities is impracticable, and then only within limits on occupancy and building height
• fire escapes must be of metal or concrete (with a limited wood exception for combustible buildings), of the stair type extending to ground level, built in a strong, substantial manner and securely fixed to the building
• fire escape stairs are limited to 45 degrees from horizontal, with risers no more than 210 mm and treads at least 220 mm wide exclusive of nosing
• a bottom flight that is not fixed in position must be held up without a latch, be counterbalanced, come down easily and reach the ground

So a fire escape on an Ontario building is a steel stair, possibly with a counterbalanced drop flight, not a vertical ladder. Fire escape work on an existing building is a permit matter for a designer and the municipality. Our guide to Ontario Building Code rules for steel stairs covers stair geometry in general.

Choosing the right type of steel ladder

A few questions narrow the choice quickly:

1. How often is it used? Daily use, or use while carrying parts and tools, points to a stair or ship ladder. Occasional maintenance access suits a fixed ladder.
2. How high is the climb? Over 5 m in an Ontario workplace means a cage and rest platforms, or a safety system where the exemption applies.
3. Is there room? A vertical ladder takes the least floor space; a ship ladder needs more; a stair needs the most.
4. What does it attach to? Concrete, masonry, steel framing or a tank shell each need a different bracket and anchor.
5. What is the exposure? Exterior, wet and below-grade ladders are normally galvanized.

Answer those and the type, and most of the details, follow.

Getting a steel ladder made

We fabricate custom steel ladders, cages, ship ladders and platforms, with CWB certified welding and shop drawings prepared in-house, and we can prime or galvanize to suit the location. Engineering services are available for anchorage and platform design. Installation is by your installer or contractor.

Send us the height, location, photos and any drawings for a free quote, or see our services for the rest of our miscellaneous steel work.