Alternating Tread Ladder Details

Stair slope of either 56 or 68 degrees requires a smaller overall footprint than a standard stair.

Alternating tread ladder details.

Industrial stairway with platform footprint. I ve done alternating tread stairs before also called ship ladders. As with all precision s products these stairs are built to project conditions and shipped to the job site completely assembled ready for installation. Designed to be used as a stair with users facing the direction of travel when climbing up and down.

Aluminum alternating tread stair is an alternative to a traditional ships stair. The steeper the angle the larger the rise. Precision ladders at series of aluminum alternating tread stairs were designed with tubular siderails to provide maximum structural integrity while keeping the overall stair weight to a minimum. The idea behind them is your foot only uses half of the stair so you can cut the other half out to allow more step up room between treads that would otherwise overlap the space savings of a ladder but will full treads and a reasonable rise.

The unused half tread is removed to provide more tread depth for improved safety and comfort. Designed with tubular side rails to provide maximum structural integrity while keeping the overall stair weight to a minimum. But with an alternating tread stair the difference in height between the right and left treads is the unit rise using the guidelines of commercially built alternating tread stairs i try to get the unit rise between 6 1 2 in.