Identify the Ladder for You

Exiting through a roof hatch or floor door.

This type of ladder has a small projection of side rail above the top tread to prevent your foot from sliding off the end. The top tread is designed to be at the base of the roof hatch (where it meets the deck or blocking). Make sure to space the ladder inside the hatch giving the climber the 7” to the center line of the rungs.

Suggestion - A Ladder Safety Post is not required by code but is a smart addition. The post can be extended once the hatch is opened to give the climber something to hold on to while transferring in or out of the hatch.

Exiting Straight Ahead To A Roof Edge, Platform, Or Catwalk

There are several names for the 42” side rail extension required by code for a step through ladder (walkthru, roof-over, extensions, etc) but the requirement is the same. This extension is there to give the climber something to hold onto as he steps on and off the ladder. OSHA and ANSI have different opinions of the required width for the climber at the top tread, but each range includes 24”, so Precision Ladders builds our walkthru ladders with 24” clear treads.

Suggestion – Be aware of obstructions on the wall (gutters, overhangs, conduit, etc). Make sure you allow the proper clearance behind the ladder at all times (7” to the center line of the rung).

Exiting To The Side

This variation is most common climbing out of pits, barn lofts or at a rest platform. The side rail and rungs must continue a minimum of 48” above the exit rung level. This design gives the climber a hand and foot hold as he access the elevated space.

Suggestion – Make sure you have a rung level with the exit point surface. This enables a smoother transition on and off the ladder.

Crossing Over A Parapet Wall

This type of ladder is a sub-set of the walkthru ladder (listed above). This style of ladder will have a long side and a return or back side.  Both ladders will have the side rail extensions of 42” and most will have a parapet platform between the two. These landing keep climbers off the top of the wall – which can be damaged and lead to water leaks.

When to use a Ships Ladder

A ships ladder (or inclined ladders) gives a more relaxed climb but sacrifices floor space. These products range between 60° and 70° allowing the designer some leeway with the footprint. Any ships ladder not terminating at a hatch will require a walk thru and in the case of a ships ladder the handrails are extended the 42” rather than the side rails. These ladders can be used in conjunction with a platform to form a crossover or bridge ladder. These are very common on roofs to get over duct work or piping.

Suggestion – OSHA doesn’t have a code dedicated to the modern ships ladder, request a unit that meets the IBC 2012 code.

When to use an Alternating Tread Ladder

This product is a close cousin to a Ships Ladder. The Alternating Tread Ladder has the same trade off as the Ships Ladder, ease of climb vs. floor space, with the added advantage of facing the directing of travel. These units come in only two angles (68° - standard and 56° - optional). The applications are the exact same for the Alternating Tread Ladders as the Ships Ladders.