Wis. Admin. Code Department of Safety and Professional Services SPS 327.20

Current through September 30, 2024

Section SPS 327.20 - Loads and materials

Every camping unit shall be designed and constructed in accordance with the requirements of this section.

(1) DESIGN LOAD. Every camping unit shall be designed and constructed to support the actual dead load and live loads acting upon it without exceeding the allowable stresses of the material. The construction of camping units shall result in a system that provides a complete load path capable of transferring all loads from point of origin through the load-resisting elements to the ground.

(a)Dead loads. Every camping unit shall be designed and constructed to support the actual weight of all components and materials. Earth-sheltered camping units shall be designed and constructed to support the actual weight of all soil loads.

(b)Live loads. Floors and ceilings shall be designed and constructed to support the minimum live loads listed in Table 327.20-1. The design load shall be applied uniformly over the component area.

Table 327.20-1

Component	Live Load (pounds per sq. ft.)
Floors	40
Exterior balconies and porches	40
Ceilings (with storage)	20
Ceilings (without storage)	5

(2) METHODS OF DESIGN. All camping units shall be designed by the method of structural analysis or the method of accepted practice specified in each part of this code.

Note: See ch. NR 116, rules of the department of natural resources, for special requirements relating to buildings located in flood plain zones. Information regarding the elevation of the regional flood may be obtained from the local zoning official.

(3) STRUCTURAL STANDARDS.

(a)General. Design, construction, installation, practice and structural analysis shall conform to the following nationally recognized standards.

(b)Wood.

1. Structural lumber, glue-laminated timber, timber pilings, and fastenings shall be designed in accordance with the National Design Specification for "Wood Construction" and the Design Values for Wood Construction," a supplement to the National Design Specification for Wood Construction, except the provisions of section 4.1.7 shall also apply to reused lumber. Reused lumber shall be considered to have a duration of load factor of 0.90.

2. Span tables for joists and rafters approved by the department may be used in lieu of designing by structural analysis.

3. Sawn lumber that is not graded in accordance with the standards under subd. 1., shall use the NDS published allowable design stresses for the lumber species using grade number 3 when used for studs, stringers, rafters or joists and may use grade number 1 when used for beams, posts, or timbers.

(c)Whole logs. Camping units constructed of whole logs shall conform to ICC 400, Standard on the Design and Construction of Log Structures.

Note: This standard requires the minimum log diameter to be 8 inches.

(d)Fasteners.

1. All building components shall be fastened to withstand the dead load and live load.

2. Fasteners shall comply with the schedule listed in Table 327.20-2, except other fastening methods may be allowed if engineered under s. SPS 327.20(3).

Table 327.20-2

MINIMUM FASTENER SCHEDULE TABLE

Other interior and exterior panel products and finishes installed per manufacturer requirements.

For engineered connectors, use manufacturer's specified fasteners.

Description of Building Materials/Connection	Number and Type of Fastener^{1 2 3}
Floor Framing
Joist to joist, face nailed over support	3-8d
Joist to sill or girder, toe nail	3-8d
Band or rim joist to joist, end nail	3-16d
Band or rim joist to sill or top plate	2-16d at 16 o.c.
Bridging to joist, toe nail each end	2-8d
Built-up girder and beams, top loaded	10d at 32" o.c. at top and bottom and staggered and two at ends and at each splice
Built-up girder and beams, side-loaded	16d at 16" o.c. at top and bottom and staggered and two at ends and at each splice
Ledger strip to beam, face nail	3-16d each joist
Joist on ledger to beam, toe nail	3-8d
Wall Framing
Sole plate to joist or blocking, face nail	2-16d at 16" o.c.
Top or sole plate to stud, end nail	2-16d
Stud to sole plate, toe nail	3-8d or 2-16d
Doubled studs, face nail	10d at 24" o.c.
Doubled top plates, face nail	10d at 24" o.c.
Doubled top plates, minimum 24" offset of end joints, face nail in lapped area	8-16d
Top plates, laps and intersections, face nail	2-10d
Continuous header, two pieces	16d at 16" o.c. along each edge
Continuous header to stud, toe nail	4-8d
1" corner brace to each stud and plate, face nail	2-8d or 2 staples, 1 3/4"
Built-up corner studs	10d at 24" o.c.
Roof/Ceiling Framing
Ceiling joists to plate, toe nail	3-8d
Ceiling joist, laps over partitions, face nail	3-10d
Ceiling joist to parallel rafters, face nail	3-16d
Rafter to plate, toe nail (maximum 6 rafter span, engineered connector for longer)	2-16d
Roof rafters to ridge, valley or hip rafters, toe nail	4-16d
Roof rafters to ridge, valley or hip rafters, face nail	3-16d
Collar ties to rafters, face nail	3-8d
Boards and planks
1" x 6" subfloor or less to each joist, face nail	2-8d or 2 staples, 1 3/4"
Wider than 1" x 6" subfloor toe to each joist, face nail	3-8d or 4 staples 1 3/4"
2" subfloor to joist or girder, blind and face nail	2-16d
1" x 6" roof or wall sheathing to each bearing, face nail	2-8d or 2 staples, 1 3/4"
1" x 8" roof or wall sheathing to each bearing, face nail	2-8d or 3 staples, 1 3/4"
Wider than 1" x 8" roof sheathing to each bearing, face nail	3-8d or 4 staples, 1 3/4"
2" planks	2-16d at each bearing

Panel Sheathing

Spacing of Fastener
Material	Fastener	Edges	Intermediate Supports
Engineered wood panel for subfloor and roof sheathing and wall corner wind bracing to framing
5 /16" to 1/2"	6d common or deformed nail or staple, 1 1/2"	6"	12"⁴
5 /8" to 3/4"	8d smooth or common, 6d deformed nail, or staple, 14 ga. 1 3/4"	6"	12"⁴
7 /8" to 1"	8d common or deformed nail	6"	12"
1 1 /8" to 1 1/4"	lOd smooth or common or 8d deformed nail	6"	12"
Combination subfloor/ underlayment to framing
3/4" or less	6d deformed or 8d smooth or common nail	6"	12"
7/8" to 1"	8d smooth, common or deformed nail	6"	12"
1 1 /8" to 1 1/4"	10d smooth or common or 8d deformed nail	6"	12"
Wood panel siding to framing
1/2" or less	6d corrosion-resistant siding and casing nails	6"	12"
5/8"	8d corrosion-resistant siding and casing nails	6"	12"
1/2" structural cellulosic fiberboard sheathing	1 1/2" galvanized roofing nail; 8d common nail; staple 16 ga., 1 1/2" long	3"	6"
25/32" structural cellulosic fiberboard sheathing	1 3/4" galvanized roofing nail; 8d common nail; staple 16 ga., 1 3/4" long	3"	6"
1/2" gypsum sheathing⁵	1 1/2" galvanized roofing nail; 6d common nail; staple galvanized 1 1/2" long; 1 1/4" screws. Type W or S	4"	8"
5/8" gypsum sheathing⁵	1 3/4" galvanized roofing nail; 8d common nail; staple galvanized 1 5/8" long; 1 5/8" screws. Type W or S	7"	7"

(4) ALTERNATE MATERIALS AND STANDARDS. No part of this code is intended to prohibit or discourage use of alternate, equivalent materials or standards or the construction of innovative or nonconventional camping units.

¹ All nails are smooth-common, box or deformed shank except where otherwise stated.

² Nail is a general description and may be T-head, modified round head or round head.

³ Staples are 16-gauge wire, unless otherwise noted, and have a minimum 7 /16" o.d. crown width.

⁴ Staples shall be spaced at not more than 10" o.c. at intermediate supports for floors.

⁵ Apply vertically 4" x 8" or 4" x 9" panels.

Wis. Admin. Code Department of Safety and Professional Services SPS 327.20

Adopted by, EmR1703: emerg. cr., eff. 2-6-17; CR 17-017: cr. Register March 2018 No. 747, eff. 4/1/2018