addedsection04720.pdf

CHATTOOGA RIVER RANGER OFFICE CAST STONE

MOMA 0204.17 11/02/07 04720-1

SECTION 04720

CAST STONE

PART 1 - GENERAL

1.1 SUMMARY

A. This Section includes the following:

Cast stone windowsills.

Cast stone coping.

1.2 SUBMITTALS

A. Shop Drawings: Show fabrication and installation details for cast stone units. Include dimensions;

details of anchorages, if any; and indication of finished faces.

Include building elevations showing layout of units and locations of joints and anchors.

B. Samples: For color and texture of cast stone required, 10 inches square in size.

PART 2 - PRODUCTS

2.1 MANUFACTURERS

A. Manufacturers: Subject to compliance with requirements, provide products by one of the following:

Architectural Cast Stone Corp.

Architectural Cast Stone, Inc.

ConArt, Inc.

Dallas Cast Stone Co., Inc.

United Cast Stone.

2.2 CAST STONE MATERIALS

A. General: Comply with ASTM C 1364 and the following:

B. Portland Cement: ASTM C 150, Type I, containing not more than 0.60 percent total alkali when tested according to ASTM C 114.

C. Coarse Aggregates: Granite, quartz, or limestone complying with ASTM C 33; gradation as needed to produce required textures.

D. Fine Aggregates: Manufactured or natural sands complying with ASTM C 33; gradation as needed to produce required textures.

E. Reinforcement: Deformed steel bars complying with ASTM A615/A 615M.

Galvanized Coating: ASTM A 767/A 767M.

F. Embedded Anchors and Other Inserts: Fabricated from steel complying with ASTM A 36/A 36M, and hot-dip galvanized to comply with ASTM A 123.

2.3 CAST STONE UNITS

A. Provide cast stone units complying with ASTM C 1364.

Provide units that are resistant to freezing and thawing as determined by laboratory testing according to ASTM C 666, Procedure A, as modified by ASTM C 1364.

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B. Fabricate units with sharp arris and details accurately reproduced with indicated texture on all exposed surfaces, unless otherwise indicated.

Slope exposed horizontal surfaces at least 1:12, unless otherwise indicated.

Provide raised fillets at backs of sills and at ends indicated to be built into jambs.

Provide drips on projecting elements, unless otherwise indicated.

C. Cure and finish units as follows:

Cure units in totally enclosed curing room under dense fog and water spray at 95 percent relative humidity for 24 hours.

Yard cure units until the sum of the mean daily temperatures for each day equals or exceeds 350 deg F.

Acid etch units to remove cement film from surfaces indicated to be finished.

D. Colors and Textures: As selected by COR from manufacturer's full range for these characteristics.

2.4 MORTAR MATERIALS

A. Portland Cement-Lime Mix: Packaged blend of portland cement complying with ASTM C 150, Type I or Type III, and hydrated lime complying with ASTM C 207.

1. For pigmented mortars, use colored portland cement-lime mix of formulation required to produce color indicated or, if not indicated, as selected from manufacturer's standard formulations.

Pigments shall not exceed 10 percent of portland cement by weight for mineral oxides or 2 percent for carbon black.

B. Masonry Cement: ASTM C 91.

1. For pigmented mortars, use colored masonry cements of formulation required to produce color indicated or, if not indicated, as selected from manufacturer's standard formulations. Pigments shall not exceed 5 percent of masonry cement by weight for mineral oxides or 1 percent for carbon black.

C. Mortar Aggregate: ASTM C 144.

1. White-Mortar Aggregates: Natural, white sand or ground, white stone.

2.5 ACCESSORIES

A. Anchors: Type and size indicated, fabricated from stainless steel complying with ASTM A 276 or ASTM A 666, Type 304.

B. Dowels: Round stainless-steel bars complying with ASTM A 276, Type 304, 1/2-inch (12-mm) diameter.

C. Job-Mixed Detergent Solution: Solution of ½ cup of dry-measure tetrasodium polyphosphate and ½ cup of dry-measure laundry detergent dissolved in 1 gallon of water.

2.6 MORTAR MIXES

A. Setting Mortar: Comply with ASTM C 270, Proportion Specification, Type S.

1. Limit cementitious materials to portland cement and lime.

2. Pigmented Mortar: Select and proportion pigments with other ingredients to produce color required. Do not exceed pigment-to-cement ratio of 1:10, by weight.

PART 3 - EXECUTION

3.1 EXAMINATION

A. Examine substrates and conditions, with Installer present, for compliance with requirements for installation tolerances and other conditions affecting performance of cast stone.

B. Proceed with installation only after unsatisfactory conditions have been corrected.

MOMA 0204.17 11/02/07 04720-3

3.2 INSTALLATION

A. Set cast stone as indicated on Drawings. Install anchors, supports, fasteners, and other attachments indicated or necessary to secure units in place. Set units accurately in locations indicated with edges and faces aligned according to established relationships and indicated tolerances.

B. Drench units with clear water just before setting.

C. Set units in full bed of mortar with full head joints, unless otherwise indicated. Build anchors and ties into mortar joints as units are set.

Fill dowel holes and anchor slots with mortar.

Fill collar joint solid as units are set.

D. Rake out joints for pointing with mortar to depths of not less than 3/4 inch (19 mm). Rake joints to uniform depths with square bottoms and clean sides. Scrub faces of units to remove excess mortar as joints are raked.

E. Point mortar joints by placing and compacting mortar in layers not greater than 3/8 inch (10 mm).

Compact each layer thoroughly and allow to become thumbprint hard before applying next layer.

3.3 INSTALLATION TOLERANCES

A. Variation from Plumb: Do not exceed 1/8 inch in 10 feet or ¼ inch in 20 feet or more.

B. Variation from Level: Do not exceed 1/8 inch in 10 feet or ¼ inch in 20 feet or 3/8 inch maximum.

C. Variation in Joint Width: Do not vary joint thickness more than 1/8 inch in 36 inches or one-fourth of nominal joint width, whichever is less.

D. Variation in Plant between Adjacent Surfaces (Lipping): Do not exceed 1/16-inch difference between planes of adjacent units or adjacent surfaces indicated to be flush with units.

3.4 ADJUSTING AND CLEANING

A. Remove and replace stained and otherwise damaged units and units not matching approved Samples.

Cast stone may be repaired if methods and results are approved by COR.

B. Replace units in a manner that results in cast stone matching approved Samples, complying with other requirements, and showing no evidence of replacement.

C. In-Progress Cleaning: Clean cast stone as work progresses. Remove mortar fins and smears before tooling joints.

D. Final Cleaning: After mortar is thoroughly set and cured, clean exposed cast stone as follows:

1. Remove large mortar particles by hand with wooden paddles and nonmetallic scrape hoes or chisels

2. Protect adjacent surfaces from contact with cleaner by covering them with liquid strippable masking agent, polyethylene film, or waterproof masking tape.

3. Wet wall surfaces with water before applying cleaners; remove cleaners promptly by rinsing thoroughly with clear water.

END OF SECTION