Alternating Tread Device Width

Winder treads shall have a minimum tread depth of 11 inches 279 mm measured at a right angle to the tread s leading edge at a point 12 inches 305 mm from the side where the treads are narrower and a minimum tread depth of 10 inches 254 mm.

Alternating tread device width.

Alternating tread devices in accordance with section. Precision ladders at series of aluminum alternating tread stairs were designed with tubular siderails to provide maximum structural integrity while keeping. These stairs allow the user to descend face forward giving a clear view of the floor below. International building code ships ladder requirements.

On its own this is a great advantage. Alternating tread devices shall have a minimum projected tread of 5 inches 127 mm a minimum tread depth of 8 5 inches 216 mm a minimum tread width of 7 inches 178 mm and a maximum riser height of 9 5 inches 241 mm. Minimum depth of 4. Precision s aluminum alternating tread stair is an alternative to a traditional ships stair.

The alternating tread stair appears in the image s center with green colored treads. Alternating tread devices and ships ladders alternating tread devices and ships ladders are now permitted as a means of egress for lofts with an area that does not exceed 200 square feet. The tread s leading edge. The alternating stair requires one unit of space per step.

3 means of egress components doors stairs ramps and exit passageways are the most common means of egress components. The projected tread depth shall be measured horizontally between the vertical planes of the foremost projections of adjacent treads. According to the international building code 2018 ship ladders cannot be used as a means of egress with one exception the exception per ibc 2018 1011. Clarification r312 1 r312 1 guards the guard requirements only apply to the specific portion of a walking surface that exceeds 30 inches above grade.

The image on the right illustrates the space efficiency gained by an alternating tread stair. The same as the half width step on its left and half as much as the full width stair on its right. These highly adaptable stairs meet relevant building codes and create a safer work environment. The clear width should be at least 18 wide.

The code also permits fire escape ladder alternating tread devices and slide escapes in certain occupancies. More tread depth means a larger stepping surface and greater stability for the user. Alternating tread stairs provide the same space saving benefit but more than twice the usable tread depth as a ships ladder or ship stair. The tread depth shall be measured horizontally between the vertical planes of the foremost projections of adjacent treads.