Section 321.08. Fire separation and dwelling unit separation.

 

(1)   Fire separation. Dwelling units shall be separated from garage spaces, accessory buildings, property lines and other dwelling units in accordance with Table 321.08 and the following requirements: - See PDF for table

1 Distance shall be measured perpendicular from wall to wall or property line, ignoring overhangs.

2 Fire rated construction shall protect the dwelling from an exterior fire source.

3 Fire rated construction may be in either facing wall.

4 Fire rated construction shall be in both facing walls.

5 The methods for garage separation in par. (a) 1. are examples of ¾ hour wall construction.

(a) Attached garages.

1. The walls and ceiling between an attached garage and any portion of the dwelling, including attic or soffit areas, shall be ¾ -hour fire-resistive construction or shall be constructed as specified in any of the following:

a. One layer of 5 / 8 -inch Type X gypsum drywall shall be used on the garage side of the separation wall or ceiling.

b. One layer of ½ -inch gypsum drywall shall be used on each side of the separation wall or ceiling.

c. Two layers of ½ -inch gypsum drywall shall be used on the garage side of the separation wall or ceiling.

2. For all methods listed under subd. 1. , drywall joints shall comply with one of the following:

a. Joints shall be taped or sealed.

b. Joints shall be fitted so that the gap is no more than 1 / 20 -inch with joints backed by either solid wood or another layer of drywall such that the joints are staggered.

3. Vertical separations between an attached garage and a dwelling shall extend from the top of a concrete or masonry foundation to the underside of the roof sheathing or fire-resistive ceiling construction.

(b) Structural elements exposed in an attached garage. Beams, columns and bearing walls which are exposed to the garage and which provide support for habitable portions of the dwelling shall be protected by one of the methods specified in par. (a) 1. a. or c. or other ¾ hour fire-resistive protection.

(c) Doors.

1. The door and frame assembly between the dwelling unit and an attached garage shall be labeled by an independent testing agency as having a minimum fire-resistive rating of 20 minutes. The test to determine the 20-minute rating is not required to include the hose stream portion of the test.

2. Only glazing allowed by the door's listing may be installed in any door required under this section.

(d) Other openings.

1. Access openings in fire separation walls or ceilings shall be protected in one of the following ways:

a. The opening is protected with a material that has a finish rating of at least 20 minutes.

b. The opening is protected in the same way as the wall or ceiling where the opening is located.

2. The cover or door of the access opening shall be permanently installed with hardware that will maintain it in the closed position when not in use.

(2)   Dwelling unit separation.

(a) General. In 2-family dwellings, dwelling units shall be separated from each other and from shared tenant spaces including attics, basements, garages, vestibules and corridors.

(b) Attic separation. Dwelling units with attic space that extends over both units shall be separated in accordance with one of the following:

1. `Complete separation.' The units shall be provided with wall construction under par. (d) that extends all the way to the underside of the roof deck.

2. `Vertical and horizontal separation.'

a. The units shall be provided with wall construction under par. (d) that extends to the dwelling unit ceiling and ceiling construction under par. (e) .

b. Dwelling units using this method of separation shall provide attic draft stopping under par. (f) that extends all the way to the underside of the roof deck above and in line with the separation wall.

(c) Doors. Any door installed in the dwelling unit separation shall have the door and frame assembly labeled by an independent testing agency as having a minimum fire-resistive rating of 20 minutes. The test to determine the 20-minute rating is not required to include the hose stream portion of the test.

(d) Walls. Walls in the dwelling unit separation shall be protected by not less than one layer of 5 / 8 -inch Type X gypsum wallboard or 2 layers of ½ -inch gypsum wallboard or equivalent on each side of the wall with joints in compliance with sub. (1) (a) 2.

(e) Floors and ceilings. A fire protective membrane of one layer of 5 / 8 -inch Type X gypsum wallboard with joints in compliance with sub. (1) (a) 2. , shall be provided on the ceiling beneath the floor construction that provides the separation.

(f) Draft stopping for concealed roof spaces and attics.

1. Attic areas, mansards, overhangs and other concealed roof spaces shall be draft stopped above and in line with the separation wall.

2. Acceptable draft stopping materials include:

a. 3 / 8 -inch wood structural panel.

b. ½ -inch gypsum board.

(3)   Penetrations.

(a) Ducts.

1. Except as allowed under subd. 2. , all heating and ventilating ducts that penetrate a required separation shall be protected with a listed fire damper with a rating of at least 90 minutes.

2. The fire damper required under subd. 1. may be omitted in any of the following cases:

a. There is a minimum of 6 feet of continuous steel ductwork on at least one side of the penetration.

b. The duct has a maximum cross-sectional area of 20 square inches.

(b) Electrical and plumbing components. Penetrations of a required separation by electrical and plumbing components shall be firmly packed with noncombustible material or shall be protected with a listed through-penetration firestop system with a rating of at least one hour.

(c) Plastic Piping. Penetrations of a required separation by plastic pipe shall be protected by a penetration firestop system approved by the department and installed as tested in accordance with ASTM E 814 or UL 1479, with a minimum positive pressure differential of 0.01 inch of water (3 pa), and shall have an F rating of not less than the required fire-resistance rating of the assembly penetrated.

Cr. Register, November, 1979, No. 287 , eff. 6-1-80; r. and recr. Register, February, 1985, No. 350 , eff. 3-1-85; cr. (1m), am. (2), (5) (c) and Table, Register, January, 1989, No. 397 , eff. 2-1-89; am. (2), (4) and (5) (a) (intro.), renum. (5) (b) and (c) to be (5) (c) and (d) and am. (5) (d), cr. (5) (b) and (e), (6), Register, March, 1992, No. 435 , eff. 4-1-92; r. (3) (a), (5) (d), renum. (3) (b) and (c), (5) (e) to be (3) (a) and (b), (5) (d), am. (5) (a) (intro.), (6), cr. (6) (c) to (e), Register, November, 1995, No. 479 , eff. 12-1-95; r. and recr. (5) and (6) (b), am. (6) (c) and (d), r. (6) (e) and cr. (7), Register, January, 1999, No. 517 , eff. 2-1-99; r. (1) to (4), renum. (5) to (7) to be (1) to (3), and cr. (2) (e), Register, March, 2001, No. 543 , eff. 4-1-01; corrections in (2) (c) and (d) were made under s. 13.93 (2m) (b) 7., Stats., Register, March, 2001, No. 543 ; CR 02-077 : am. (1) (a) 1. and (2) (a) to (c) Register May 2003 No. 569 , eff. 8-1-03; CR 08-043 : am. (1) (intro.) and Table, r. (1) (a) 4. and (2) (e), renum. (1) (c), (2) (b), (c) and (d) to be (1) (c) 1., (2) (c), (d) and (e) and am. (2) (d), cr. (1) (c) 2., (2) (b) and (f), r. and recr. (1) (d) 1. and (2) (a) Register March 2009 No. 639 , eff. 4-1-09; correction in Table 21.08 made under s. 13.92 (4) (b) 7., Stats., Register March 2009 No. 639 ; correction in (1) (intro.) made under s. 13.92 (4) (b) 7., Stats., Register December 2011 No. 672 ; CR 15-041 : am. Table 321.08, cr. (3) (c) Register December 2015 No. 720 , eff. 1-1-16.

Note

1/20-inch is approximately the thickness of a U.S. dime. Microsoft Windows NT 6.1.7601 Service Pack 1 Acceptable tests for fire rating of door assemblies include ASTM E-152, UL 10B, and NFPA 252. Microsoft Windows NT 6.1.7601 Service Pack 1