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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.

SPIRAL STAIR TABLE OF RISERS:
*LANDING/TOP FLOOR						** CODE COMPLIANT STEP

27 Degree Step 13.3 Steps per 360 Degrees			22 1/2 Degree Step 13.3 Steps per 360 Degrees			30 Degree Step ** 12 Steps per 360 Degrees
Finish Floor Height	Number of steps/ RISERS	Total Rotation	Finish Floor Height	Number of steps/ RISERS	Total Rotation	Finish Floor Height	Number of steps/ RISERS	Total Rotation
90" - 96"	11 Steps *12Risers	297	84" - 91"	12 Steps *13Risers	270	85" - 95"	9 Steps *10 Risers	270
97" - 104"	12 Steps *13 Riser	324	92" - 98"	13 Steps *14 Riser	292.5	96" - 104"	10 Steps *11 Riser	300
105"- 112"	13 Steps *14 Riser	351	99" - 105"	14 Steps *15 Riser	315	105" - 14"	11 Steps *12 Riser	330
113"- 120"	14 Steps *15 Riser	375	106" - 12"	15 Steps *16 Riser	337.5	115" - 23"	12 Steps *13 Riser	360
121" - 28"	15 Steps *16 Riser	405	113" - 19"	16 Steps *17 Riser	360	124" - 33"	13 Steps *14 Riser	390
129" 136"	16 Steps *17 Riser	432	120" - 26"	17 Steps *18 Riser	382.5	134" - 42"	14 Steps *15 Riser	420
137" - 44"	17 Steps *18 Riser	459	127" - 33"	18 Steps *19 Riser	405	143" - 52"	15 Steps *16 Riser	450
145" - 52"	18 Steps *19 Riser	486	134" - 40"	19 Steps *20 Riser	427.5	153" - 61"	16 Steps *17 Riser	480
153" - 60"	19 Steps *20 Riser	513	14" - 147"	20 Steps *21 Riser	450	62" - 171"	17 Steps *18 Riser	510
161" - 68"	20 Steps *21 Riser	540	148" - 54"	21 Steps *22 Riser	472.5	172" - 80"	18 Steps *19 Riser	540

Any degree of step can be cut for special rotations. Stairs having to meet code are required to have 30 degree steps. This table is limited with space any height below or above this chart can be acieved.

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.