Basic Specifications

The specifications shown on this website may be copied. Furnish and install, where shown on the plans, Spiral Stairs as manufactured by Duvinage Corp., Hagerstown, Maryland.

Duvinage manufacturing standards are published in SWEET'S CATALOG FILE, 2000-2004 Editions. Installation must proceed in accordance with manufacturer's directions and approved shop detail drawings.

Duvinage standards are stated on this website and in the product catalog. Duvinage has the capability to furnish any custom spiral and circular stair to its customers' specifications.

Engineering

A spiral stair must be well designed, comfortable and functional. Proper selection of radius, riser height, tread degree and materials are the necessary factors. Duvinage continuously achieves the highest standard in engineering through its many years of experience.

Machined Hubs

Machined hubs are used to exact riser height. The stair slips easily over the center pole and rests flush on the hub beneath. This method minimizes installation labor. Duvinage stairs are pre-assembled at the plant, marked, and inspected prior to shipment. No field welding is required.

Bracing

Landing platforms that are attached to the construction at the top of each flight provide anchorage for the stair. Lateral braces are included where required.

Landing Platforms

90-degree platforms are the standard to fit square, round, or special size well openings. Platforms can be installed at any desired level to accommodate multi-floor landings or rest points between floors. When necessary, additional head room can be obtained by using less than 90-degree platforms.

Tread Degree

Treads are available in 22 1/2, 28 and 30-degree angles for right or left hand stairs.