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§ 1541.05
<br />DWELLING HOUSE CODE
<br />44
<br />in contact with soil, shall be 600 psi and the
<br />average of any five units shall be not less
<br />than 700 psi.
<br />(d) Load-bearing, exposed to weathering.
<br />The minimum compressive strength in
<br />pounds per square inch of average gross area
<br />for any individual hollow concrete masonry
<br />unit used in exterior walls below grade when
<br />in contact with soil, or in exterior walls
<br />above grade where exposed to and not pro-
<br />tectedagainst the action of the weather, shall
<br />be 800 psi and the average of any five units
<br />shall be not less than 1000 psi. '
<br />(e) Nor load-bearing in protected loca-
<br />tions. Hollow concrete masonry units used
<br />in non-load-bearing masonry, not subject to
<br />the action of weather or soil, shall conform
<br />to the requirements of ASTM C 129.
<br />(f) Solid masonry units. Solid concrete
<br />masonry units shall conform to the require-
<br />ments ,of ASTM C 145.
<br />1541.05 Cast stone.
<br />Cast stone shall conform to the require-
<br />ments of ACI 704.
<br />1541.06 Natural stone.
<br />Stone for masonry shall be sound and free
<br />from loose or friable inclusions. It shall have
<br />sufficient strength, durability, and resistance
<br />to impact for the proposed use.
<br />1541.07 Architectural terra cotta.
<br />Architectural terra cotta shall have a
<br />strong homogeneous body and give a sharp,
<br />metallic, bell-like ring when struck, All
<br />units shall have the necessary anchor holes
<br />and shall be so formed as to engage with the
<br />supporting structure.
<br />1541.08 Glazed masonry units.
<br />Glazed masonry units shall conform to the
<br />requirements of ASTM C 126, except that
<br />the requirements for finish shall not apply
<br />to salt-glazed masonry units.
<br />1.5.41.09 Gypsum file and block.
<br />Gypsum partition'tile or block shall con-
<br />form to the 'requirements of ASTM C 52:
<br />Gypsum partition file or block shall not be
<br />used in bearing :walls or in exterior walls,
<br />or where subject.to continuous dampness.
<br />1541.10 Structural glass block.
<br />Glass blocks may be solid or hollow. ~ All
<br />mortar bearing surfaces of the blocks shall
<br />be pre-coated with a material to improve
<br />adhesion between mortar and -glass. Except
<br />as otherwise approved- by the Building Of-
<br />fic~al, structural glass .block shall have. a
<br />n~iilimum thickness _ of .3374 .inches and .a
<br />maximum face dimension of 12 inches, and
<br />except that special shapes within the stated
<br />dimension limits may be used for corners,
<br />curves and trim.
<br />1541.11 It<Iortar materials.
<br />(a) Cementitious materials. Cementitious
<br />materials used in mortars shall conform to
<br />the requirements of the following applicable
<br />standard specifications:
<br />Quicklime for Structural Purposes,
<br />ASTM C 5.
<br />Hydrated Lime f or Masonry, ASTM C 207.
<br />Unless the hydrated lime conforms to Type
<br />S of these specifications, lime to be added to
<br />mortar shall first be made into lime putty at
<br />least 24 hours before incorporation into the
<br />mortar.
<br />Hydraulic Hydrated Lime for Structural
<br />Purposes, ASTM C 141.
<br />Natural Cement, ASTM C 10.
<br />Masonry Cement, Federal Specification
<br />SS-C-181b: ASTM C 91.
<br />Portland ,Cement, ASTM C 150, ASTM
<br />C 175 or ASTM C 205.
<br />Gypsum, ASTM C 22.
<br />(b) Aggregate specifications. Aggregate
<br />for mortar shall be natural sand, clean and
<br />well-graded from fine to coarse and shall
<br />conform to the requirements of ASTM C
<br />144. The coarsest particle of sand shall be
<br />not more than one-half the thickness of the
<br />mortar joint, but in no event larger than
<br />that passing a No. 4 sieve.
<br />(c) Water. Water used in mixing mortar
<br />shall be clean, and free from deleterious
<br />amounts of acids, alkalis, or organic ma-
<br />terials.
<br />(d) Volume of aggregate. The volume of
<br />aggregate in mortar shall be at least 2.4 times
<br />but not more than 3 times the volume of ce-
<br />mentitious material.
<br />(e) Types o f mortar-strength. Mortar
<br />used in masonry construction shall be classi=
<br />fled as follows: .
<br />Min' C
<br />~YPe
<br />A ~ 2500 '
<br />B 600
<br />C .: 200 .
<br />D :. 75 :.
<br />R (for reinforced brick 2500
<br />. masonry) -. '
<br />(f) Types of mortar-~oroportions._ Unless
<br />the. strength classification of the mortar has
<br />been established.by acceptable tests; mortars
<br />nnum ompressive
<br />Strength of.2-inch
<br />Cubes at 28 Days (psi)
<br />
<br />4~
<br />
<br />81
<br />CFIAPTER 81. EXTERIOR FINISH.
<br />1581.01 Type of wall coverings.
<br />= `The.following materials shall be accepted
<br />as approved weather coverings of the mini-
<br />mum thickness specified:
<br />Brick masonry veneers __~___2 inches
<br />Stone veneers ______________2 inches
<br />Cellular architectural
<br />terra cotta _______________3 inches
<br />Architectural terra cotta
<br />slabs ---------------------174 inches
<br />Structural clay file ________--13/4 inches
<br />Stucco'------------ --------3/4 inch
<br />Wood siding ----------------~/a inch
<br />Protected combustible siding ~/z inch
<br />Wood shingles ______________3/s.inch
<br />Exterior plywood ___________5/16 inch
<br />Asbestos shingles ______-____5/32 inch
<br />Asbestos cement boards _____~/a inch
<br />Aluminum clapboard siding__0.030 inch
<br />Farmed metal siding ________28 U. S. gage
<br />1581.02 Securing wood or metal siding and
<br />roof covering.
<br />All shingle, wood or metal siding and roof
<br />covering shall be securely nailed with alumi-
<br />num, copper, zinc, zinc coated or other ap-
<br />proved corrosion-resistive nails into the sup-
<br />porting structure in accordance with. sub-
<br />mitted nailing schedules approved by the
<br />Building Official. .Shingles and other
<br />weather coverings attached directly to
<br />sheathing less than nominal l" thick shall'be
<br />secured with barbed or other mechanically-
<br />bonding nails, or by common nails on furring
<br />strips attached to the studs.
<br />1581.03 'Masonry veneers.
<br />(a) Installation on masonry. .Masonry
<br />veneers on masonry backing shall be in-
<br />stalled in accordance with subsection 1541.15
<br />~d). ,
<br />(b) Installation over wood. ar other
<br />sheathing. Veneers of unit masonry on wood
<br />framing shall be securely attached to the
<br />wood frame with corrosion-resistive anchors
<br />at .vertical .intervals of not more than 17"
<br />and.. horizontal intervals of„not. more than
<br />32".' When other than wood_board sheathing
<br />is used,, metal ties shall be, secured to the
<br />studs. Sheathing surfaces back.of masonry
<br />veneer shall be covered with water-resistant,
<br />vapor-permeable building paper or saturated
<br />feit`unlesswoter-repellent sheathing is used.
<br />;,
<br />"(c) Support:' Masonry veneers shall rest
<br />directly upon the masonry foundation or be
<br />carried liy the masonry walls, of the_struc-
<br />tureand shall notbe supported on wood con-
<br />.. . .
<br />_.._ ..
<br />struction:
<br />1581.04 Stucco.
<br />(a) Reinforcement. All stucco work shall
<br />be reinforced with metal lath or wire fabric,
<br />except when applied directly to a masonry
<br />base. The reinforcing fabric shall be coated
<br />with zinc or other rust-resisting coating or
<br />shall be manufactured from corrosion-re-
<br />sistive alloys.
<br />(b) Backing. When applied over sheath-
<br />ing, acovering of 14-pound waterproof felt
<br />or paper shall first be attached to the sheath-
<br />ing. Inback-plastered stucco with the stucco
<br />extending not less than 5/s inch back between
<br />the studs, the waterproof paper backing may
<br />be omitted: All metal reinforcement shall
<br />be furred. away from sheathing or building
<br />paper not less than 174 inch with self-furring
<br />lath, metal strips or furring nails.
<br />1581.05 Metal veneers.
<br />(a) Quality. Metal veneers that are ex-
<br />posed to the weather shall be of corrosion-
<br />resistant metal, or of metal that is covered
<br />front and back with porcelain enamel or
<br />otherwise protected with a treatment or
<br />coating to render the metal corrosion-resist-
<br />ant.
<br />(b) Attachment. Metal veneer shall be
<br />securely attached to the supporting masonry
<br />or framing members with corrosion-resistant
<br />fastenings spaced not more than 24 inches
<br />horizontally and not more than 17 inches
<br />vertically, except where wider spacing is
<br />specifically approved by the Building .Offi-
<br />cial. When units exceed 4 square feet in
<br />area, there shall be not less than four at-
<br />tachments per unit.
<br />(c) Supports. Metal supports for metal
<br />veneers shall be protected by painting, gal-
<br />vanizing, or other equivalent coating or
<br />treatment. Woad studs, furring strips, or
<br />other wood supports for metal veneer shall
<br />be pressure treated with a preservative, or
<br />otherwise protected against' decay in a man-
<br />rier approved by the Building.Official. ": .
<br />(d) Calking grid pointing: All joints and
<br />edges in metal veneers that are exposed to
<br />the weather shall be calked or pointed with
<br />durable waterproof material, or shall be pro-
<br />tected by other means to prevent penetration
<br />of water.
<br />1581.06 Painting. .. .
<br />(a)' Wood surfaces:. A priming coat'shall
<br />be applied and worked into all exterior wood
<br />surfaces. Nail holes. and cracks -shall be
<br />puttied after the. pruning coat.: Not less than
<br />two coats of paint shall then be applied'to the
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