VA 09 24 00-2011 PORTLAND CEMENT PLASTERING.pdf

1、10-11 09 24 00 - 1 SECTION 09 24 00 PORTLAND CEMENT PLASTERING SPEC WRITER NOTE: 1. Delete between /_ / if not applicable to project. 2. Delete any other item or paragraph not applicable in the section and renumber the paragraphs. Coordinate and show on Room Finish Schedule cement plaster finish to

2、clearly defined locations. 3. Use cement plaster in showers and similar wet areas. Coordinate with Section 09 06 00, SCHEDULE FOR FINISHES and VA criteria for finishes. Do not use over open frame construction on exterior walls. PART 1 GENERAL 1.1 DESCRIPTION This section specifies lathing and Portla

3、nd cement based plaster / (stucco)/. 1.2 RELATED WORK A. Steel framing members for attachment of plaster bases: Section 05 40 00, COLD-FORMED METAL FRAMING, and Section 09 22 16, NON-STRUCTURAL METAL FRAMING. B. Room finish schedule and color: Section 09 06 00, SCHEDULE FOR FINISHESS. C. Gypsum plas

4、ter: Section 09 23 00, GYPSUM PLASTERING. D. Veneer plaster: Section 09 26 00, VENEER PLASTERING. 1.3 TERMINOLOGY A. Definitions and description of terms shall be in accordance with ASTM C11, C841, and C926 and as specified. B. Underside of Structure Overhead: In spaces where steel trusses or bar jo

5、ists are shown, the underside of structure overhead shall be the underside of the floor or roof construction supported by beams, trusses, and bar joists. C. Self-furring Lath: Metal plastering bases having dimples or crimps designed to hold the plane of the back of the lath 6 to 10 mm (1/4 to 3/8 in

6、ch) away from the plane of the solid backing. D. Solid Backing or Solid Bases: Concrete, masonry, sheathing, rigid insulation, and similar materials to which plaster is directly applied. E. Wet Areas: Areas of a building where cyclic or continuous exposure to very humid or wet conditions, or in whic

7、h a dew point condition may occur in the plaster. Dew point conditions occur frequently in such Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-10-11 09 24 00 - 2 areas as laundries, natatoriums, cart and dish washing spaces, hydrotherapy, kitchens,

8、bathing or shower rooms and similar areas. 1.4 SUBMITTALS A. Submit in accordance with Section 01 33 23, SHOP DRAWINGS, PRODUCT DATA, AND SAMPLES. B. Manufacturers Literature and Data: 1. Accessories for plaster, each type. 2. Metal plastering bases, each type. 3. Fasteners. 4. Bonding compounds, in

9、cluding application instructions. 5. Admixtures, including mixing and application instructions. C. Samples: Accessories for plaster, each type, not less than 150 mm (6 inches) long. SPEC WRITER NOTE: Request plaster sample where color is specified or special finish is required, and where required to

10、 match existing special finish conditions. Specify a size to suit requirements, 150 to 300 mm (6 by 12 inches) minimum. Panel showing finish coat _ by _ mm (inches). 1.5 PROJECT CONDITIONS A. Maintain work areas for interior work at a temperature of not less than 4C (40F) for not less than 48 hours

11、prior to application of plaster, during application of plaster and until plaster is completely dry. B. Exterior plaster shall not be applied when the ambient temperature is less than 4C (40F). C. Plaster shall not be applied to frozen surfaces or surfaces containing frost. D. Frozen materials shall

12、not be used in the mix. E. Plaster coats shall be protected against freezing for a period of not less than 24 hours after application. 1.6 APPLICABLE PUBLICATIONS A. The publications listed below form a part of this specification to the extent referenced. The publications are referenced in the text

13、by basic designation only. B. American Society for Testing And Materials (ASTM): A653/A653M-10 Steel Sheet, Zinc-Coated (Galvanized) or Zinc-Iron Alloy-Coated (Galvannealed) by the Hot-Dip Process A641-09 Zinc-Coated (Galvanized) Carbon Steel Wire Provided by IHSNot for ResaleNo reproduction or netw

14、orking permitted without license from IHS-,-,-10-11 09 24 00 - 3 C11-10 . Terminology Relating to Gypsum and Related Building Materials and Systems. C91-05 . Masonry Cement C150-09 Portland Cement C207-06 Hydrated Lime for Masonry Purposes C260-10 Air Entraining Admixtures for Concrete. C841-08 Inst

15、allation of Interior Lathing and Furring C847-10 Metal Lath C897-05(R2009) . Aggregate for Job-Mixed Portland Cement Based Plasters C926-06 Application of Portland Cement-Based Plaster C933-09 Welded Wire Lath C979-10 Pigments for Integrally Colored Concrete C1002-07 . Steel Self-Piercing Tapping Sc

16、rews for the Application of Gypsum Panel Products or Metal Plaster Bases to Wood Studs or Steel Studs C. Commercial Item Description (CID): A-A-55615 Shield, Expansion (Wood Screw and Lag Bolt Self-Threading Anchors) D. Federal Specifications (Fed Spec.): UU-B-790A Building Paper, Vegetable Fiber (K

17、raft, Waterproofed, Water Repellent and Fire Resistant) PART 2 - PRODUCTS SPEC WRITER NOTE: Make material requirements agree with applicable requirements specified in the referenced Applicable Publications. Update and specify only that which applies to the project. 2.1 METAL PLASTERING BASES A. Expa

18、nded Metal Lath: 1. ASTM C847, zinc-coated (galvanized) except as modified by ASTM C841 and this specification. Self furring where applied over solid backing. 2. Flat diamond mesh weighing not less than 1.8 kg/m2 (3.4 pounds per square yard). 3. Stucco Mesh: Flat expanded diamond mesh pattern, with

19、openings approximately 38 by 75 mm (1-1/2 by 3 inches), weighing not less than 1.9 kg/ m2 (3.6 pounds per square yard), with backing as specified. B. Wire Lath: 1. Zinc coated (Galvanized). Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-10-11 09 24

20、00 - 4 2. Welded Wire Lath: ASTM C933, with backing as specified. 3. Self furring where applied over solid backing. C. Building Paper Backing for Metal Plastering Bases: 1. Backing attached to lath as specified in ASTM C933. 2. Vapor Permeable Backing: Fed. Spec. UU-B-790, Type I, Grade D. 3. Water

21、Resistant Backing: Fed. Spec. UU-B-790, Type I, Grade B. 2.2 ACCESSORIES FOR CEMENT PLASTER (STUCCO) A. ASTM C841, except fabricate from zinc alloy. B. Control Joints: ASTM C841, zinc. 2.3 FASTENERS A. Tie, wire, screws, clips, and other fasteners ASTM C841, except as otherwise specified. B. Fastene

22、rs for securing metal plastering bases shall have heads, or be through washers large enough to engage two strands of the metal plastering base. C. For fire rated construction; type and size as used in fire rated test. D. Screws: ASTM C1002. E. Expansion Shields: CID A-A-55615, of the Type and Class

23、applicable. 2.4 CEMENT A. Portland: ASTM C150, Type I. B. Masonry: ASTM C91. Lime where added, ASTM C207, Type S. C. White where required for white finish coat. 2.5 LIME A. ASTM C206, Type S. B. ASTM C207, Type S. 2.6 AGGREGATES (SAND) A. ASTM C897, graded as required to suit texture of finish speci

24、fied. B. White where white finish coat is specified. 2.7 BONDING AGENT ASTM C932. 2.8 FACTORY PREPARED FINISH COAT FOR CEMENT PLASTER (STUCCO) A. Factory prepared dry blend of materials, integrally colored, designed for exterior finish coat application. B. Pigments: ASTM C979, lime proof mineral oxi

25、de. C. Not more than 35 percent, by weight of all ingredients (cement, aggregate, hydrated lime, admixture and coloring pigment) shall pass a number 100 sieve. 2.9 ADMIXTURES Air Entrainment: ASTM C260. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,

26、-10-11 09 24 00 - 5 SPEC WRITER NOTE: Existing solid bases to be plastered may require extensive surface preparation or application of lath to provide positive anchorage. Use of lath is required over sheathing. Conform to Uniform Building Code for seismic conditions on exterior walls. PART 3 - EXECU

27、TION 3.1 METAL PLASTERING BASES (LATH) LOCATIONS A. Where plaster is required on solid concrete or masonry bases, metal plastering bases are not required, unless shown on the drawings. Where shown use wire lath or stucco mesh. B. On ceiling or soffit framing use flat diamond mesh lath. C. On interio

28、r wall framing: 1. Use flat diamond mesh lath. 2. Use lath with water resistant backing in wet areas. D. Over steel columns, use self-furring flat diamond mesh lath. E. Where metal plastering bases are used as a base for exterior cement plaster over wall sheathing, use wire lath or stucco mesh with

29、water resistant backing. 3.2 APPLYING METAL PLASTERING BASES A. In accordance with ASTM C841, except as otherwise specified or shown. B. Form true surfaces, straight or in fair curves where shown, without sags or buckles and with long dimension of lath at right angles to direction of supports. C. La

30、th for ceiling or soffit construction shall terminate at casing bead (floating angle construction) at perimeter angles between walls and ceilings or soffits. D. Lath with backing shall be applied to produce a paper to paper and metal to metal lap at ends and sides of adjacent sheets, whether full sh

31、eets or less than full sheets are used: 1. Backing shall be lapped 50 mm (2 inches) for both horizontal and vertical laps. 2. Horizontal laps shall be ship lap fashion to conduct water to the outside and over flashing or waterproofing. E. Metal plastering bases shall not be continuous through expans

32、ion and control joints, but shall be stopped at each side. F. Attach metal lath directly to masonry and concrete with hardened nails, power actuated drive pins or other approved fasteners. Fasteners shall be located at the dimples or crimps only. G. Wood plugs are not acceptable. Provided by IHSNot

33、for ResaleNo reproduction or networking permitted without license from IHS-,-,-10-11 09 24 00 - 6 3.3 INSTALLING PLASTERING ACCESSORIES A. Install accessories in accordance with ASTM C841, except as otherwise specified. 1. Set plastering accessories plumb, level and true to line, neatly mitered at c

34、orners and intersections, and securely attach to supporting surfaces as specified for metal lath. 2. Install in one piece, within the limits of the longest commercially available lengths. B. Corner Beads: Install at all vertical and horizontal external plaster corners, as required to establish groun

35、ds, and where shown. C. Strip Lath: 1. Install metal lath strips centered over joints between dissimilar materials, such as hollow tile, brick, concrete masonry units, concrete, and joints with metal lath on framing or furring, where both such surfaces are required to be plastered and are in contact

36、 with each other in same plane, except where expansion joints and casing beads are required. 2. Wire tie or fasten strip lath to base along both edges at not over 150 mm (six inches) on centers. D. Casing Beads: 1. Install casing beads where shown and at following locations where plaster terminates

37、to provide finish trim. 2. Where plaster terminates against non-plastered surfaces such as masonry, concrete, and wood. 3. Where plaster terminates against trim of steel frames and trim of other materials and equipment, except where trim overlaps plaster. 4. Around perimeter of openings except where

38、 edge is covered by flanges. Locate to conform to dimensions shown on shop drawings. 5. Where plaster for new walls or furring (vertical or horizontal) terminates against existing construction. 6. Both sides of expansion and control joints unless shown otherwise. 7. Install casing bead at perimeter

39、angles between walls and ceilings so as to provide floating angle (unrestrained) construction in accordance with ASTM C841. E. Cornerites: 1. Install at interior corners of walls, partitions, and other vertical surfaces to be plastered, except where metal lath is carried around angle. 2. Fasten only

40、 as necessary to retain position during plastering. 3. Omit cornerites at junction of new plastered walls with existing plastered walls at locations where casing beads are specified. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-10-11 09 24 00 - 7

41、F. Control Joints: SPEC WRITER NOTE: 1. Show and clearly define on drawings location of control joints. 2. Install control joints to create panels no larger than 13.4 m2 (144 square feet) with no dimension exceeding 5.4 m (18 feet) or a length to width ratio of 2-1/2 to 1. 3. Install control joints

42、at all locations where panel size or dimensions change. 4. Detail control joints. 1. Where control joints are placed parallel to framing members, install joints within 100 mm (four inches) of the framing member. 2. Install control joints only to the edges of abutting sheets of lath so that the lath

43、is not continuous or tied across the joint. 3. Joints shall extend the full width and height of the wall or length of soffit/ceiling plaster membrane. 3.4 SURFACE PREPARATION OF SOLID BASES A. Surfaces that are to receive plaster shall be prepared and conditioned in accordance with ASTM C926, except

44、 as otherwise specified. B. New surfaces of masonry and concrete: 1. Remove projections and clean concrete surface of form oil. 2. Fill depressions, holes, cracks and similar voids flush with Portland cement plaster to provide substrate within the tolerance specified in ASTM C926. 3. Use bonding age

45、nt. 4. Cover with self furring lath where required to keep the total plaster thickness as specified in Table 4 of ASTM C926. SPEC WRITER NOTE: Read ASTM C926 regarding Requirements for Bases to Receive Portland Cement-based plaster. Check concrete specification to see that finish specified will rece

46、ive plaster. New concrete should not need preparation other than that specified in 3.4, A and B. Examine condition of existing surfaces to receive plaster and specify only one of following methods for each condition. C. Existing surfaces of concrete and masonry: 1. Clean surface of dirt and other fo

47、reign matter which will prevent bond. 2. Apply dash bond coat or bonding agent as specified herein. 3. Where existing surfaces have a coating such as paint or bituminous waterproofing apply metal plastering base as specified herein. Provided by IHSNot for ResaleNo reproduction or networking permitte

48、d without license from IHS-,-,-10-11 09 24 00 - 8 3.5 PORTLAND CEMENT BASED PLASTER A. Provide portland cement based plaster where cement plaster (stucco) is shown and specified, and as follows: 1. Three coat work shall be used over all metal plastering bases, with or without solid backing. 2. Two c

49、oat work may only be used over solid bases meeting the requirements of Paragraph, SURFACE PREPARATION OF SOLID BASES. B. Proportion, mix and apply plaster in accordance with ASTM C926, except as otherwise specified. 1. Use air entrained plaster for all exterior work. 2. Use coloring pigments for finish coat when integral color other than white is specified. 3. Use white