A. General:
1. Materials: See Section 8-1A-3-4 of this Article.
2. Mortar:
a. Masonry below grade, Portland cement mortar: one part Portland cement, three (3) parts sand by volume. Lime, not more than twenty five percent (25%) of the cement by volume, may be added.
b. All other masonry:
(1) Portland cement mortar: See paragraph a above.
(2) Cement-lime mortar: One part Portland cement, one part lime putty, six (6) parts sand by volume.
(3) Prepared masonry cement mortars: One part masonry cement, three (3) parts sand by volume; add no materials other than sand and water.
c. Retempering of mortar: This may be permitted up to one and one-half (11/2) hours after mixing. All mortar shall be used within two (2) hours after mixing.
3. Joints:
a. Maximum thickness, five-eighths inch (5/8"). Joints for decorative stone work may be increased one-fourth inch (1/4"). All joints to be uniform in thickness.
b. Solid masonry units: Fill joints solid.
c. Hollow masonry units: No through mortar joints.
d. Fill all joints solid both sides of wall.
4. Bonding:
a. Walls of solid masonry units: Solid masonry bearing and nonbearing walls shall be bonded in accordance with one of the following methods:
(1) Bonding with headers: The facing and backing shall be bonded with a header course consisting of alternate through header and stretcher every seventh course, or one through header in every two hundred forty (240) square inches, uniformly placed throughout wall.
(2) Bonding with metal ties: The facing and backing shall be bonded with corrosion-resistant metal ties conforming to requirements of subsection G4 of this Section for cavity walls. There shall be one metal tie for not more than each four and one-half (41/2) square feet of wall area. Ties in alternate courses shall be staggered. The maximum vertical distance between ties shall not exceed eighteen inches (18"), and the horizontal distance shall not exceed thirty six inches (36"). Walls so bonded shall conform to the thickness (excluding cavity), height and mortar requirements for cavity walls.
b. Masonry walls on hollow units: Where two (2) or more hollow units are used to make up the thickness of a wall, bonding shall be in accord with recommendations of American Standard Building Code Requirements for Masonry M. P. No. 211 (7-15-1954) Section 72.
c. Stone walls:
(1) Ashlar masonry, bond stones uniformly distributed shall be provided to the extent of not less than ten percent (10%) of exposed faces.
(2) Rubble stone masonry twenty four inches (24") or less in thickness shall have bond stones with a maximum spacing of three feet (3') vertically and three feet (3') horizontally, and if the masonry is of greater thickness than twenty four inches (24"), shall have one bond stone for each six (6) square feet of wall surface on both sides.
d. Intersecting concrete and masonry walls shall be bonded together in an approved manner.
5. Closed Cell Hollow Units: Use for rough openings, corners and wall intersection. Filling exposed ends of cells not acceptable.
6. Protection: Provide frost protection acceptable to Building Official when temperature falls below freezing; except, that no masonry work shall be done in temperatures below twenty degrees (20°) Fahrenheit. (Protection as outlined by American Standard Building Code Requirements for Masonry M P-211 shall be considered acceptable practice.)
7. Loading: Allow sufficient time for strength of masonry to develop before subjecting to loads.
B. Masonry Unit Foundation Walls: Masonry unit foundation walls shall not be allowed and their use in new construction is hereafter forbidden.
C. Dampproofing and Waterproofing: Dampproof basement or cellar walls on exterior from finish grade to outside edge of footing:
1. Masonry Unit Walls: Apply one-half inch (1/2") thick Portland cement plaster coat forming a cove at the footing, over which apply at least one heavy coat of undiluted hot tar, asphalt or compound acceptable to the Building Official.
2. Concrete Walls Cast in Place: Apply at least one heavy coat of undiluted hot tar, asphalt or compound acceptable to the Building Official.
D. Piers:
1. When Acceptable: Piers only acceptable for one-story accessory buildings, open porches and carports.
2. Materials: Masonry units or cast-in-place concrete. See Section 8-1A-3-4 of this Article.
3. Minimum Sizes in Inches:
a. Masonry, twelve inches (12") by twelve inches (12").
b. Plain concrete, ten inches (10") by ten inches (10") or twelve inch (12") round.
4. Maximum Spacing:
a. Exterior wall piers supporting floor joists, eight feet (8') on center.
b. Exterior wall piers in line parallel to joists and interior piers, twelve feet (12') on center.
5. Minimum height above grade, six inches (6").
6. When of hollow masonry units, cap with at least four inches (4") solid masonry or concrete. See subsection B1e of this Section.
7. Sill anchor bolts or dowels to be installed.
8. Piers shall be poured to within one-half inch (1/2") of correct grade and shimmed with metal plates, cement asbestos shims or acceptable hardwood blocks.
E. Exterior Walls Above Grade:
1. Materials: All materials shall meet the requirements of Section 8-1A-3-4 of this Article.
2. Allowable Heights and Thicknesses:
a. In residence buildings not more than two (2) stories in height, walls other than coursed or rough or random rubble stone walls, may be of eight inch (8") thickness when not over thirty feet (30') in height from grade to ridge at gable ends, and when the roof is designed to impart no lateral or horizontal thrust. When the roof imparts a horizontal thrust, such walls shall have a minimum thickness of twelve inches (12").
b. Rough or random or coursed rubble stone walls shall be not less than sixteen inches (16") in thickness.
c. Hollow walls of masonry units shall not exceed thirty feet (30') in height from grade to ridge of gable ends; except, that ten inch (10") cavity walls shall not exceed twenty five feet (25') in height above the support of such walls. The facing and backing shall each have a thickness of at least a nominal four inches (4") and the cavity shall be not less than two inches (2") (actual) nor more than three inches (3") in width. The facing and backing of cavity walls shall be bonded with metal ties. (See subsection A4a(2) of this Section.)
d. Walls in one-story residence buildings, and one-story private garages, may be of six inch (6") thickness when not over ten feet (10') in height when solid structural clay masonry units are used, or nine feet (9') in height for hollow structural clay masonry units, except that an allowance of an additional six feet (6') is permitted for gables.
3. Maximum Height for Eight (8") Inch Thickness: Twenty two feet (22') from grade to eaves, or thirty feet (30') from grade to ridge in gable ends. For greater heights, minimum thickness twelve inches (12") except top twenty two feet (22').
4. Backing, When Used, Solid or Hollow Masonry Units, Minimum Thickness:
a. Bonded to facing, four inches (4").
b. Tied to facing with sheet metal ties, eight inches (8").
5. Furring When Interior Finish is Applied: Not less than one inch (1") wood strips. Spacing as permitted for interior finish 1 . Bituminous waterproofing materials on masonry not acceptable for plaster base. Install horizontal furrier strips at ceiling and floor to form fire stops and prevent convection.
6. Lintels: Size to be determined by span in each case. No concentrated loads over nonreinforced lintels.
a. Lintels may be:
(1) Precast concrete and brick reinforced.
(2) Stone.
(3) Masonry arch.
(4) Steel. See ASTM A7-56T.
b. Support on four inches (4") of solid masonry.
7. Rafter Plate Anchor Bolts to be Installed:
a. Diameter, one-half inch (1/2") minimum.
b. Minimum length in masonry unit walls, fifteen inches (15"); poured concrete walls, ten inches (10").
c. In masonry walls, washer and three inch (3") square plate on bolts.
d. Spacing, not more than eight feet (8') on center.
8. Radiator Recesses:
a. Construct at time wall is built.
b. Maximum recess depth, four inches (4") in eight inch (8") walls, eight inches (8") in twelve inch (12") walls.
c. Back and sides of recess to be waterproofed and insulated.
d. Width under windows not greater than rough opening.
9. Vertical Chases:
a. Construct at time wall is built.
b. Maximum length for chases where net wall thickness is eight inches (8") or less, four feet (4').
c. Maximum chase depth, four inches (4").
d. Back and sides of chase to be plastered with one-half inch (1/2") of Portland cement mortar.
10. Horizontal Chases:
a. Not acceptable unless wall thickness is at least four inches (4") greater than thickness required under subsection E2 of this Section.
b. Maximum depth, four inches (4").
F. Masonry Veneer:
1. Minimum thickness:
a. Brick, three and three-fourths inches (33/4").
b. Ashlar stone masonry, four inches (4").
c. Rubble-stone masonry, uncoursed (field stone), twelve inches (12"); mosaic or random, twelve inches (12"); coursed, one story, eight inches (8"); over one story, twelve inches (12").
2. Masonry Veneered Wood Frame Construction: Veneer applied over sheathing with air space between.
a. Air space: Three-fourths inch (3/4") between masonry veneer and sheathing.
b. Base flashing: Copper extending over top of foundation wall from outside face of wall and not less than twelve inches (12") up on sheathing.
c. Apply water-resistant building paper or saturated asphalt felt over sheathing. Lap base flashing at least four inches (4").
d. Bonding: Corrosion-resisting metal ties spaced not more than fifteen inches (15") vertically and thirty two inches (32") on center horizontally. When other than wood board sheathing is used, secure ties through to studs with corrosion-resistant nails of length sufficient to penetrate wood at least one inch (1").
e. Lintels: Size to be determined by materials and span in each case. Bearing, at least four inches (4"). Arches permitted.
G. Cavity Walls:
1. The minimum thickness of the inner and outer wythes of cavity walls shall not be less than a nominal four inches (4"), and the nominal out to out dimension of the wall shall not be less than ten inches (10").
2. The maximum height of ten inch (10") cavity walls and the width of the cavity shall conform to the requirements of subsection E2c of this Section.
3. All masonry units shall be laid in a full head and bed mortar joint. The mortar used in cavity wall construction shall conform to the requirements of Portland cement mortar or cement-lime mortar. (See subsections A2a and A2b of this Section.)
4. The facing and backing of cavity walls shall be bonded with three-sixteenths inch (3/16") diameter noncorrosive steel rods or metal ties of equivalent stiffness embedded in the horizontal joints. There shall be one metal tie for not more than each four and one-half (41/2) square feet of wall area. Ties in alternate courses shall be staggered, the maximum vertical distance between ties shall not exceed eighteen inches (18"), and the maximum horizontal distance shall not exceed thirty six inches (36"). Rods or ties bent to rectangular shape shall be used with hollow masonry units laid with the cells vertical; in other walls, the ends of the ties shall be bent to ninety degree (90o) angles to provide hooks not less than two inches (2") long. Additional bonding ties shall be provided at all openings, spaced not more than three feet (3') apart around the perimeter and within twelve inches (12") of all openings.
5. Noncorrodible flashing shall be placed over the top of all openings, at window sills and at the bottom of the cavity.
6. Weep holes shall be provided in the exterior wythe along all flashing. The weep holes shall be spaced not more than twenty four inches (24") on centers. Every effort shall be made to keep the cavity clear of mortar droppings.
7. Furring: See subsection E5 of this Section.
H. Interior Masonry Walls:
1. Material: Masonry or cast-in-place concrete.
2. Pipes Recesses: Construct at time walls are built.
3. Party and Fire Walls:
a. Minimum thickness: Cast-in-place concrete, six inches (6"); masonry units, eight inches (8"). Chases or recesses not permitted. See paragraph 4d below.
b. Flat roofs: Extend above roof, flash and cap with stone, concrete, vitrified tile or terra cotta.
c. Under pitched roofs: Build masonry solid to underside of roof sheeting unless carried above roof.
4. Bearing Partitions:
a. Minimum thickness of plain concrete or unit masonry wall shall be not less than a nominal six inches (6").
b. Sections of walls with distance between openings two feet (2') or less: Solid masonry units or hollow units filled with concrete.
c. Lintels: Steel, reinforced concrete or masonry arches. Minimum, four inch (4") bearing upon solid masonry at least four inches (4") thick.
d. Joist bearings: Solid masonry at least four inches (4") thick.
e. Girder bearing: Solid masonry at least eight inches (8") thick.
5. Nonbearing Partitions:
a. Minimum thickness, three inches (3").
b. Lintels: Steel, reinforced concrete or masonry, or masonry arches.
1. Provide Masonry Chimney:
a. Separate flue required for each fireplace.
b. Separate flue required for each appliance fired with natural-draft oil burner. Separate flues required for all other equipment, depending upon sustained chimney draft for proper operation, unless combined flue is specifically approved by the Building Official.
2. Materials: Solid masonry; footing concrete cast in place.
3. Effective Flue Area: At least as recommended by the manufacturer of equipment connected to chimney and at least equal to area of outlet (smoke or vent) of equipment connected to it; minimum diameter for house heating flue, eight inches (8"). For fireplaces, effective area not less than one-tenth (1/10) of fireplace opening.
4. Chimney Linings, Wythes and Walls:
a. Glazed fire clay flue lining required in all chimneys for liquid and solid fuels. When gas is used as fuel, provide flue lining of metal or composition acceptable to the Building Official, or glazed fire-clay lining or vitrified tile lining, bell and spigot type, bell end up, all with joints made with acid-resisting mortar. Provide drain to dispose of condensation.
b. Two (2) flues may be grouped without a wythe of masonry between them, provided the joints of the linings are staggered at least seven inches (7").
c. Wythes separating flues or groups of flues with linings not staggered, three and three-fourths inches (33/4") minimum thickness.
d. Walls, minimum thickness, three and three-fourths inches (33/4") in addition to lining.
5. Height of Chimney: As recommended by equipment manufacturer, and not less than two feet (2') above the ridge of the roof that the chimney penetrates and not less than two feet (2') above the highest ridge within fifteen feet (15') of the chimney.
6. Cap chimney to form wash from flue to outside edge, minimum thickness, two inches (2").
7. Metal thimbles and clean-out doors to be built in at the time chimney is constructed.
J. Fireplaces:
1. Smoke Chamber and Damper: Smoke chamber and damper required in all fireplaces.
2. Minimum Wall Thickness: Eight inches (8") in addition to the lining.
3. Ash Dump: When provided, empty into concrete or masonry chamber provided with metal cleanout door.
4. Linings: Two inch (2") fire brick or other material acceptable to Building Official.
5. Hearth:
a. Support independently on masonry or concrete.
b. Projection from chimney breast, at least sixteen inches (16").
c. Width, at least eight inches (8") wider than fireplace opening on each side.
d. Material, incombustible.
e. Combined thickness of hearth and support, six inches (6").
6. Fireplace Opening Lintels: Use brick arch, concrete, stone or steel.
7. Facing: Masonry, no combustible material closer than three and one-half inches (31/2") to fireplace opening.
K. Glass Block:
1. May not use as load-bearing units.
2. Maximum size of unsubdivided panel: Area one hundred forty four (144) square feet; length twenty five feet (25'); height twenty feet (20').
3. Provide for expansion. (Ord. 0-71-12, 3-11-71)
Notes
| 1 | 1. See Section 8-1A-3-13 of this Article. |
| 2 | 1. See also Section 8-2-3 of this Code. |