Stair Design Information

Clockwise

Layout:

By using the Table of Risers chart below and applying the finish floor to finish floor height, you can determine the number of treads required. For a stair built to code, a 30 degree tread is required. If you do not have build to code, you may select any of the three tread alternatives. Check the number of steps and degree of turn your stair will have. Rotate the diagram four different directions to determine which direction best meets your needs. You can have less of a turn by decreasing the number of steps.

Counter Clockwise

Framing Dimensions:
(Fully Assembled and All
Wood Kits)

Model No.	1	2	3	4	5	6
40S	22 in.	22 in.	22 in.	44 in.	44 in.	22 in.
48S	26 in.	26 in.	26 in.	52 in.	52 in.	26 in.
52S	28 in.	28 in.	28 in.	56 in.	56 in.	28 in.
60S	32 in.	32 in.	32 in.	64 in.	64 in.	32 in.
64S	34 in.	34 in.	34 in.	68 in.	68 in.	34 in.
72S	38 in.	38 in.	38 in.	76 in.	76 in.	38 in.
76S	40 in.	40 in.	40 in.	80 in.	80 in.	40 in.
88S	46 in.	46 in.	46 in.	92 in.	92 in.	46 in.
96S	50 in.	50 in.	50 in.	100 in.	100 in.	50 in.

These framing dimensions are used when stair passes through flooring and you are not using a landing. Notice that the opening an "L" shaped, not square. For maximum head room taper 45" joist #2 (shaded area) 45°. If your joist is 10" or over, order the stair with one less tread as this will increase available head room.

Table of Risers:

27 degrees			22 1/2 degrees			30 degrees
Finish Floor Height	Number of Steps	Degree of Circle	Finish Floor Height	Number of Steps	Degree of Circle	Finish Floor Height	Number of Steps	Degree of Circle
90" to 96"	11	297	84" to 91"	12	270	85" to 95"	9	270
97" to 104"	12	324	92" to 98"	13	292 1/2	96" to 104"	10	300
105" to 112"	13	351	99" to 105"	14	315	105" to 114"	11	330
113" to 120"	14	375	106" to 112"	15	337 1/2	115" to 123"	12	360
121" to 128"	15	405	113" to 119"	16	360	124" to 133"	13	390
129" to 136"	16	432	120" to 126"	17	382 1/2	134" to 142"	14	420
137" to 144"	17	459	127" to 133"	18	405	143" to 152"	15	450
145" to 152"	18	486	134" to 140"	19	427 1/2	153" to 161"	16	480
153" to 160"	19	513	141" to 147"	20	450	162" to 171"	17	510
161" to 168"	20	540	148" to 154"	21	472 1/2	172" to 180"	18	540

Stair Elevation

Tread Detail

Dimension Chart:

Model #	40S	48S	52S	60S	64S	72S	76S	88S	96S
Diameter	40"	48"	52"	60"	64"	72"	76"	88"	96"
Center Column	4"	4"	4"	4"	4"	4"	6.625"	6.625"	6.625"
Lbs. per 9 ft.	205	220	235	250	365	310	322	435	485
Tread Detail A	3.50"	3.50"	3.50"	3.50"	3.50"	3.50"	5.625"	5.625"	5.625"
Tread Detail B	18"	22"	24"	28"	30"	34"	36"	42"	48"
22-1/2° Tread Detail C	7.85"	9.42"	10.21"	11.78"	12.56"	14.13"	14.92"	17.28"	18.85"
27° Tread Detail C	9.312"	11.187"	12.125"	14"	14.312"	16.812"	17.75?	20.562"	22.437"
27° Tread Detail D	7.375"	7.75"	7.875"	8"	8.125"	8.25"	8.375"	9.75"	9.875"
30° Tread Detail C	10.375"	12.437"	13.437"	15.562"	16.562"	18.625"	19.687"	22.75"	24.875"
30° Tread Detail D	7.50"	7.50"	7.50"	7.50"	7.50"	7.50"	7.50"	7.50"	7.50"
Platform Size	22"	26"	28"	32"	34"	38"	40"	46"	50"

Specifications:

Furnish spiral stairway as manufactured by Stairways Inc., 4166 Pinemont Houston, Texas 77018 (1-800-231-0793). Stairway shall be shipped in a complete single unit.

Experience:

Three Generations of experience allows reliability and on-time delivery of an outstanding product.

Structural Performance:

Stairways, Inc. spiral stairs to meet any job specifications. It is the customer's complete responsibility to notify us of building codes or special requirements.

Codes:

National Building Codes (BOCA) or Uniform building code requires a minimum of a 60" diameter spiral with 30 degree treads and a 4" on center maximum spacing for balusters. Before ordering, check with your local building inspector for code requirements in your application.

Coatings & Surface:

Standard primer, zinc-chromated reddish brown rust inhibitor, black acrylic enamel , epoxies, or hot dipped galvanization applied over chemically cleaned surfaces.

Code Acceptability:

We will design and manufacture stairs to meet any job specifications. It is the customer's complete responsibility to notify us of building codes or special requirements.

Materials & Finishes:

Stairways are made from a variety of materials: Steel, Aluminum, Stainless Steel, Brass, Bronze, Oak, Pine, Walnut, Teak and Cherry. Available Finishes include: Mill, Polished, Satin or Coated.