Section 321.26. Masonry walls.

  Masonry walls shall be constructed in accordance with the requirements of this section.

(1)   Cold weather work. When ambient air temperature is below 40 ° F, the cold weather construction procedures under ACI 530.1 shall be followed.

(2)   Masonry units.

(a) Unused concrete units. Previously unused concrete masonry units shall conform to the ASTM C 90 standard.

(b) Unused clay or shale units. Previously unused clay or shale masonry units shall conform to the appropriate ASTM standard: C 62; C 216; or C 652. Units which will be exposed to weathering or frost action shall be Grade SW as specified in these standards.

(c) Used masonry units. All previously used masonry units shall be free from physical defects which interfere with the installation or impair the structural properties of the unit.

(3)   Types of mortar.

(a) Mortar specifications. The type of mortar shall be determined from Table 321.26-A. The mortar shall conform to the requirements of ASTM C-270.

(b) Surface bond mortars. Surface bond mortars for masonry walls shall be mixed in accordance with the proportions specified on the bag.

(4)   Mortar components. Mortar components shall comply with the following requirements:

(a) Water. Water shall be clean and free of deleterious amounts of acids, alkalies, or organic materials.

(b) Admixtures or mortar colors. Admixtures or mortar colors shall not be added to the mortar unless the resulting mortar conforms to the mortar specifications. Only mineral oxide may be used as mortar color and shall not exceed 10% by weight of the cement.

(c) Mixing. Mortar shall be mixed for at least 3 minutes after all ingredients have been added with the maximum amount of water to produce a workable consistency. Mortars that have stiffened due to water evaporation shall be retempered by adding water as frequently as needed to restore the required consistency. Mortars shall be used and placed in final position within 2 ½ hours after mixing.

(d) Cementitious material. Cementitious material shall conform to the standards approved by the department.

(e) Aggregates. Aggregates for use in masonry mortar shall consist of natural sand or manufactured sand and shall be graded.

(5)   Cavity wall.

(a) Corbels. Corbels shall be constructed in accordance with ACI 530.

(b) Projections. The projection of a wall beyond the edge of a supporting member other than masonry, such as a shelf angle or edge of a beam, shall not exceed 1 ¼ inches, unless at least 2 / 3 the mass of the wythe of masonry involved is located directly over the load-carrying member.

(6)   Openings and lintels.

(a) Openings. The masonry above openings shall be supported. The bearing length of structural elements which support the masonry above the opening shall be not less than 4 inches.

(b) Lintels. Unless designed through structural analysis, lintels shall be provided using either steel angles or reinforcing bars in accordance with Table 321.26-C. - See PDF for table

(7)   Masonry veneers.

(a) Veneer over frame construction.

1. Masonry veneers may be corbeled over the foundation wall, but the corbeling shall not exceed one inch.

2. A minimum one-inch air space shall be provided between the veneer and the sheathing unless a manufactured offset material is used.

3. Where no brick ledge is formed in the foundation wall, corrosion resistant metal or other water-resistant flashing shall extend over the top of the foundation wall from the outside face of the wall and shall extend at least 6 inches up on the sheathing. The flashing shall be installed to drain any water outward.

4. Weep holes shall be provided at the bottom masonry course at maximum intervals of 2 feet.

5. Ventilation openings shall be provided at the top of the wall.

6. Studs and sheathing behind masonry veneer shall be covered with material used to construct the water-resistive barrier as required under s. SPS 321.24 (4) .

7. Masonry or brick veneer shall be above final exterior grade unless there is through-wall flashing at grade or within 2 courses above grade.

(b) Veneer over masonry back-up. Corrosion-resistant metal or other water-resistant base flashing shall be provided at the bottom of the veneer and shall extend over the top of the foundation and up at least 6 inches and be embedded in the back-up course. The flashing shall be installed to drain any water outward. Weep holes shall be provided at maximum intervals of 3 feet.

(c) Veneer attachment. Veneers shall be anchored or adhered in accordance with ACI 530 and ACI 530.1.

(8)   Flashing.

(a) General.

1. Flashing shall be installed in accordance with this section to drain any water outward away from structural members, sheathing and insulation.

2. Open joints or weep holes shall be provided in the facing immediately above the flashing at a horizontal spacing not exceeding 2 feet.

3. Flashing that will be exposed to ultraviolet light shall consist of materials which are durable and permanently UV-resistant, such as sheet metal or heavy-gauge PVC.

(b) Location.

1. `Lintels and chimneys.' In exterior hollow masonry walls, flashing shall be installed at the backsides of chimneys and at the bottom of the cavity formed by openings such as lintels over doors and windows.

2. `Veneer.' Flashing shall be installed at the bottom of veneer and shall extend over the top of the foundation and up at least 8 inches and be embedded in the backing course.

(c) Weep holes.

1. Weep holes may not be placed below final grade.

2. Rope or similar material used to form a weep hole shall be removed as soon as the mortar sets.

3. Weep holes shall be 3 / 8 -inch minimum diameter.

(9)   Bearing.

(a) Concentrated loads. Beams, girders, trusses, joists and other members producing concentrated loads shall bear a minimum of 3 inches on one of the following:

1. `Concrete beam.' The equivalent of a nominally reinforced 2,500 psi concrete beam 8 inches in height.

2. `Solid masonry.' At least 8 inches in height of masonry composed of solid masonry units with all voids and joints completely filled with mortar.

3. `Metal plate.' A metal plate of sufficient thickness and size to distribute the load to masonry units. For piers and columns, the bearing plate shall not exceed 60% of the cross-sectional area of the pier or column and the resultant reaction of all vertical and horizontal loads shall fall within the middle third of the member.

4. `Bond beam.' The bond beam shall be the equivalent of not less than an 8-inch lintel (bond beam) block with 2 No. 4 bars embedded in high strength mortar fill or equivalent. The loads shall bear on the fill.

(b) Continuous loads. Joists, trusses and beams other than wood, spaced 4 feet or less on center and 40 feet or less in length, slabs or other members causing continuous loads shall be transmitted to masonry with a minimum bearing of 3 inches upon solid masonry at least 2 ½ inches in height, or as indicated for concentrated loads.

(c) Stack bond walls. Concentrated loads shall be distributed into masonry laid in stack bond by a concrete beam or bond beam as defined in par. (a) . For masonry of solid units, 2 additional rows of a continuous tie assembly may be used instead of a concrete beam or bond beam.

(d) Support of wood floor members. Where a wood structural member is buried in masonry for support, it shall be firecut or a self-releasing device shall be used. Where the end of a wood structural member is built into an exterior wall, a ½ -inch air space shall be provided at the sides, top and end of such member.

(10)   Bonding. Unless designed through structural analysis, all masonry walls shall be bonded as follows:

(a) Single-wythe walls. Masonry units in single-wythe walls shall be lapped at least 2 inches or one-third the height of the masonry unit, whichever is greater, or through the use of continuous tie assemblies spaced at 16-inch vertical intervals.

(b) Multi-wythe walls. Adjacent wythes shall be bonded with continuous tie assemblies spaced at vertical intervals not exceeding 16 inches; or individual ties of at least 3 / 16 -inch diameter for each 4 ½ square feet of wall area, spaced at a maximum vertical distance of 18 inches and a maximum horizontal distance of 36 inches; or bonded with a full course of masonry headers every seventh course. The clear distance between bond courses shall not exceed 16 inches for solid masonry units and 24 inches for hollow masonry units. Hollow walls shall not be bonded with headers.

(11)   Bolts and anchors. The allowable shear on steel bolts and anchors shall not exceed the values given in Table 321.26. - See PDF for table

(12)   Joints. Joints in masonry construction shall be constructed in accordance with ACI 530.1.

(13)   Cleaning. Chemical cleaning agents shall be prevented from harming the metal reinforcement of structural components and shall not be of a strength which will adversely affect the mortar.

Cr. Register, November, 1979, No. 287 , eff. 6-1-80; am. (3) and cr. Table 21.26-B1 Register, February, 1985, No. 350 , eff. 3-1-85; am. (9) (b), Register, January, 1989, No. 397 , eff. 2-1-89; am. (6) (b), Register, March, 1992, No. 435 , eff. 4-1-92; r. and recr. (2), am. (5) (c), (7) (a) 3., 4., (b), r. (14), Register, November, 1995, No. 479 , eff. 12-1-95; CR 02-077 : am. (7) (a) 4. Register May 2003 No. 569 , eff. 8-1-03; CR 08-043 : r. and recr. (1), (5) (a), (8) and (12), renum. (3) (intro.) and (a) to be (3) (a) and (b) and am. (3) (a), am. (4) (b) and (7) (a) 2., r. (5) (c), Tables 21.26-B and B1, cr. (7) (a) 5. to 7. and (c) Register March 2009 No. 639 , eff. 4-1-09; CR 09-104 : am. (8) (a) 3. Register December 2010 No. 660 , eff. 1-1-11; correction in (9) (c) made under s. 13.92 (4) (b) 7. , Stats., Register January 2011 No. 661 ; correction in (3) (a), (6) (b), (7) (a) 6., (11) made under s. 13.92 (4) (b) 7. , Stats., Register December 2011 No. 672 .

Note

The requirements for cold weather work are in sections 1.8 and 1.8C of the 2005 edition of the ACI standard. Microsoft Windows NT 6.1.7601 Service Pack 1 To ensure proper mortar mixing, machine mixing is recommended. - See PDF for table Microsoft Windows NT 6.1.7601 Service Pack 1 The department will accept cementitious material conforming to the following standards: ASTM C91, Masonry Cement; ASTM C150, Portland Cement; ASTM C595, Portland Blast-Furnace Slag Cement; ASTM C207, Hydrated Lime for Masonry Purposes; and ASTM C5, Quick Lime for Structural Purposes. Microsoft Windows NT 6.1.7601 Service Pack 1 The department will accept aggregates in accordance with ASTM C144. Microsoft Windows NT 6.1.7601 Service Pack 1 The ventilation opening could be other than a weep hole. Microsoft Windows NT 6.1.7601 Service Pack 1 Acceptable water-resistive barrier materials include polymeric-based house wraps and #15 or greater asphalt-saturated felts that comply with ASTM D 226 for type I felt. Microsoft Windows NT 6.1.7601 Service Pack 1 Materials including house wrap, asphalt-impregnated building paper, plastic sheeting, peel-and-stick rubberized sheet material, and light-gauge PVC are not acceptable as meeting this requirement. Microsoft Windows NT 6.1.7601 Service Pack 1 See s. SPS 321.24 (3) for further requirements relating to flashing for masonry. Microsoft Windows NT 6.1.7601 Service Pack 1