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§ 1579.15
<br />DWELLING HOUSE CODE
<br />80
<br />be added to both scratch and brown coats of
<br />lime plaster.
<br />(d) Finish coat. The proportions for finish
<br />coats shall be one volume of plaster of Paris
<br />to 3 volumes of lime putty or any other of
<br />those specified in ASA A42.1, or other pro-
<br />portions and materials approved by the
<br />Building Official.
<br />1579.15 Application of gypsum or lime
<br />plaster:
<br />Accepted good practice as defined in ASA
<br />A42.1 for the manner of application of
<br />gypsum plaster shall also be accepted good
<br />practice in the manner of application of lime
<br />plaster; except that in three-coat work, the
<br />second or brown coat of lime plaster shall
<br />be applied over a dry base coat. Lime plaster
<br />shall not be applied directly to fiber in-
<br />sulation lath or gypsum lath.
<br />1579.16 Other plastering materials and
<br />methods.
<br />Vermiculite and perlite aggregates are ac-
<br />ceptable for plaster when mixed in the pro-
<br />portions of not less than 2 nor more than 4
<br />cu, ft, of vermiculite or perlite to 1001bs. of
<br />gypsum plaster. Vermiculite plastering and
<br />vermiculite acoustical plastic shall be in ac-
<br />cordance with the Standard Specification of
<br />Vermiculite Plastering and for Vermiculite
<br />Acoustical Plastic, issued by the Vermiculite
<br />Institute.
<br />1579.17 Ceramic wall tile.
<br />(a) Quality, Ceramic wall the shall meet
<br />the requirements of FS SS-T-308, and shall
<br />be standard grade or better, with trimmer
<br />units for corners, edges, top and base.
<br />(b) Application. Unless another method
<br />of installation of ceramic wall the has been
<br />approved by the Board of Building Code Ap-
<br />peals, the base shall consist of a scratch coat
<br />of portland cement plaster, not less than 5/s
<br />inch thick, integrally waterproofed and ap-
<br />plied on metal lath. When the metal lath is
<br />not paper-backed, the studs'shall be covered
<br />with awater-resisting covering, equal to 15
<br />pound asphalt saturated felt, applied shingle
<br />style. After the scratch coat has dried, a
<br />bedding coat shall be applied of portland
<br />cement mortar or other adhesive materials
<br />approved by the Building Official.
<br />1579.18 Shower walls.
<br />In showers, and over bathtubs with
<br />showers, an approved waterproof finish wall
<br />shall be installed to a height of not less than
<br />6 feet above the floor. Joints at corners,
<br />bathtub, base and top of wainscot shall be
<br />calked and then protected with proper trim
<br />units or molding designed for the purpose or
<br />location.
<br />1579.19 Dry wall finish.
<br />(a) Minimum thickness. Plywood, wood
<br />board, gypsum. board, structural fiber in-
<br />sulating board and similar types of wall and
<br />ceiling finishes may be used when applied
<br />and joined in a manner approved by the
<br />Building Official, The minimum thickness of
<br />board for various spacing of framing mem-
<br />bers is tabulated below:
<br />Type of Board Spacing of Framing
<br />Members
<br />16" 20" 24"
<br />PlyW00d --------------- 1/4 1/4~ 3/8
<br />Gypsum ---------------- s/s 1/2 l~i*
<br />Structural insulating ____ 1/z 25/32 25/32
<br />Dense compressed
<br />composition ___________ 1/4 s/s 1/z~
<br />Wood board _____________ s/s 1/z 1/z
<br />Longer dimension at right
<br />angles to framing members.
<br />(b) Solid blocking. For framing members
<br />spaced more than 16 inches o.c., solid block-
<br />ing shall be installed behind all joints at
<br />right angles to the framing members.
<br />(c) Plywood quality. Plywood shall meet
<br />the requirements established for Interior
<br />Type in CS45, or Type II or III in CS35; ex-
<br />cept that where the use for interior finish in-
<br />cludes exposure to dampness or other severe
<br />conditions of service, Exterior Type of CS45
<br />or Type I of CS35 shall be required.
<br />(d) Gypsum board quality. Gypsum wall
<br />board shall meet the requirements of FS SS-
<br />W-51a.
<br />(e) Fiberboard quality. Structural fiber
<br />insulating board shall meet the requirements
<br />of FS LLL=F-321b and CS42.
<br />(f) Composition wallboard and hard=
<br />pressed fiberboard. Dense compressed com-
<br />position board or hard-pressed fiberboard
<br />shall meet the requirements of FS UU-W-
<br />101a or FS LLL-F-311.
<br />1579.20 Wood trim.
<br />All interior wood trim shall be thoroughly
<br />seasoned, and free of objectionable defects.
<br />Plaster and other wall finishing materials
<br />shall be dry before trim is installed.
<br />
<br />45
<br />Masonry
<br />§ 1541.14
<br />of the following proportions, with the aggre- fication given in paragraph (e) of this Sec-
<br />gatemeasured in adamp and loose condition, tion.
<br />may be assumed to meet the strength classi-
<br />PROPORTIONS BY VOLUME
<br />Mortar
<br />Type Hydrated Lime or Lime Putty;
<br />Cement Allowable Range Aggregate Measured in a
<br />Damp and Loose Condition
<br />A 1 portland 0 to 1/4 Not more than 3
<br /> 1 portland 1 to 11/4 Not more than 6
<br />B 1 masonry, FS
<br /> SS-C.-181b, Type II ______ Not more than 3
<br /> 1 portland 2 to 21/z Not more than 9
<br />C 1 masonry, FS
<br /> SS-C-181b, Type I ______ Not more than 3
<br />D 0 to 1/z portland 1 to 11/4 , Not more than 3 parts for
<br /> each part of cementitious
<br /> material.
<br />R Shall conform to the requirements of ASTM C 161.
<br /> (g) Weights of Materials. The weights
<br />. per cubic foot of the materials in mortar are
<br /> considered to be as follows:
<br /> Portland cement______94 pounds
<br /> Masonry cement___-__weight printed on bag
<br /> Hydrated Lime_______40 pounds
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<br /> 1541.12 Grouted masonry.
<br /> (a) Grout shall be made by adding to the
<br /> mortar the minimum amount of water neces-
<br /> sary to produce a pouring consistency with
<br /> no segregation of the ingredients.
<br /> (b) Grouted masonry is solid masonry in
<br /> which the outer tiers or withes are laid in
<br /> full head and bed joints of mortar and all in-
<br /> terior joints are filled with grout made of
<br /> mortar of the same- type as that used in
<br /> laying the outer tiers or withes.
<br /> (c) Increased allowable stress values.
<br /> When brick masonry is constructed as
<br /> grouted masonry, the working stresses,
<br /> tabulated in ASA A 41.1, may be increased
<br /> 50%.
<br /> 1541.13 Type of mortar or grout required.
<br /> (a) Reinforced brick masonry. Rein-
<br />, forced brick work shall be laid in Type R
<br /> mortar, or Type R mortar and grout.
<br /> (b) Other masonry. Masonry, other than
<br /> reinforced brick work, shall be laid in Type
<br /> A, Type B, or Type C mortar, except as fo1-
<br /> lows:
<br /> 1. Type A mortar shall be used in nominal
<br /> 10-inch cavity walls, foundation walls of liol-
<br /> low masonry units, and masonry linings of
<br />existing masonry walls.
<br /> 2. Type A or Type B mortar shall.be used
<br /> in footings, foundation walls of solid ma-
<br />sonry units, isolated piers including founda-
<br />tion piers, load-bearing or exterior walls of
<br />hollow masonry units, hollow walls of ma-
<br />sonry, and cavity walls exceeding 10-inch
<br />nominal thickness.
<br />3. Type, C mortar maybe used in exterior
<br />and interior walls of solid masonry, in in-
<br />terior non-load bearing walls or partitions
<br />of hollow masonry units, and in other loca-
<br />tions where the use of Type A or Type B
<br />mortar is not specifically required by this
<br />Dwelling House Cade.
<br />4. Type D mortar may be used in solid
<br />masonry walls other than parapet walls or
<br />rubble stone walls, not in contact with the
<br />soil and not less than 12 inches thick nor
<br />more than 35 feet in height, provided the
<br />walls are braced at intervals not exceeding
<br />12 times the wall thickness,
<br />5. Gypsum partition the and block shall
<br />be laid in gypsum mortar. Non-bearing par-
<br />titions and fireproofing of structural clay file
<br />may be laid in gypsum mortar. ,Gypsum
<br />mortar shall be in the proportions of not
<br />more than 3 parts sand to 1 part gypsum by
<br />weight; Gypsum mortar shall not be retem-
<br />pered.
<br />6. Fire brick shall be laid in fire clay or
<br />air-setting mortar.
<br />7. Glass block when laid in mortar shall be
<br />laid in Type B mortar.
<br />8..For. vertical interior joints in grouted
<br />masonry, other than reinforced brickwork,
<br />Type A grout shall be used with Type A
<br />mortar, and Type B grout with Type B mor-
<br />tar. ~ .
<br />1541.14 Mortar joints.
<br />Masonry built with solid masonry units
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