SPEC NOTE: This master guide specification Section is intended for use when specifying quarried limestone used in wall cladding applications.

SPEC NOTE: This master guide specification Section has been produced by a Certified Construction Specifier (CCS), in accordance with the standards and practices recommended by the Construction Specifications Institute. It specifically uses the standardized formats MasterFormat™, SectionFormat™ and PageFormat™ to organize the information.

SPEC NOTE: Optional choices are indicated by using square brackets to surround the optional text, such as [_____]. Delete any inappropriate choices, and then remove any remaining square brackets prior to final printing. Where selection is indicated with an [OR] statement, select the appropriate paragraph and delete the inappropriate statement. Delete all SPEC NOTEs and [OR] statements prior to final printing.

SPEC NOTE: Arriscraft•SPEC is a commercially developed guide specification system. Arriscraft•SPEC Sections are intended to be used by design professionals knowledgeable in specification writing techniques and masonry construction practices. They must be edited to reflect project-specific requirements. Arriscraft accepts no responsibility or liability for the completeness and accuracy of the information contained herein, nor for the accuracy or completeness of project specifications developed using the Arriscraft•SPEC system.

1		General

1.1			SECTION INCLUDES

.1	Limestone dimension stone cladding.

SPEC NOTE: Edit to suit project requirements.

1.2			RELATED SECTIONS

.1	[Section 03 30 00 – Cast-in-Place Concrete: dovetail slot anchors]

.2	Section 04 05 00 – Common Work Results for Masonry.

.3	Section 04 05 13 – Masonry Mortaring.

.4	Section 04 05 16 – Masonry Grouting.

.5	Section 04 05 19 – Masonry Anchorage and Reinforcing.

.6	Section 04 05 23 – Masonry Accessories.

.7	[Section 04 22 00 – Concrete Unit Masonry: structural substrate.]

.8	Section 05 12 00 – Structural Steel Framing: structural steel supports.

.9	[Section 05 41 00 – Load-Bearing Metal Studs: structural substrate.]

.10	Section 05 50 00 – Metal Fabrications: fabricated steel items.

.11	Section 07 21 00 – Thermal Insulation: insulation for cavity spaces.

.12	Section 07 27 00 – Air Barriers.

.13	Section 07 62 00 – Sheet Metal Flashing and Trim: reglets for flashing.

.14	Section 07 92 00 – Joint Sealants: rod and sealant between stone and other building components.

SPEC NOTE: Edit the following Article in conjunction with the requirements of Part 2 – Products and Part 3 – Execution. Delete those reference standards not required by the Project. Insert the correct date for each applicable standard.

SPEC NOTE: For further information regarding the content or availability of any of these reference standards, contact the author organization, as follows:
•	American Society of Civil Engineers, www.asce.org 
•	American Society for Testing and Materials, www.astm.org
•	International Masonry Institute, www.imiweb.org  

1.3			REFERENCES

.1	ASTM C97-[__]: Standard Test Methods for Absorption and Bulk Specific Gravity of Dimension Stone.
 
.2	ASTM C99-[__]: Standard Test Method for Modulus of Rupture of Dimension Stone.

.3	ASTM C170-[__]: Standard Test Method for Compressive Strength of Dimension Stone.

.4	ASTM C241-[__]: Standard Test Method for Abrasion Resistance of Stone Subjected to Foot Traffic.

.5	ASTM C880-[__]: Standard Test Method for Flexural Strength of Dimension Stone.

.6	ASTM C568-[__]: Standard Specification for Limestone Dimension Stone.

.7	ASTM C1242-[__]: Standard Guide for Design, Selection, and Installation of Exterior Dimension Stone Anchors and Anchoring Systems.

.8	TMS 602-[__]: Specifications for Masonry Structures.

SPEC NOTE: The following Article should only be used when a Performance-based specification is desired. It implies the need for expertise beyond that which exists on the part of the building designer, necessitating the retention of a professional engineer specializing in cladding design. Specifiers should determine, based on preliminary design, whether such additional skills are required, based upon one or more of the following: knowledge of the performance record of the contemplated systems; materials or connections; complexity of the cladding and/or connection system; unusual or extreme loading conditions; unusual frame or structural configuration.

SPEC NOTE: Retaining a cladding engineer will add substantial cost to the Project, and should only be used if deemed absolutely necessary. If such need does not exist, then do NOT use this Article.

1.4			DESIGN REQUIREMENTS

.1	General: Design, fabricate and install stone cladding to withstand normal loads from wind, gravity, movement of building structure, and thermally induced movement, as well as to resist deterioration under conditions of normal use including exposure to weather, without failure.

.2	Retain the services of a cladding engineer, as described below, to design the cladding support and retention system. Cladding engineer will prepare engineering calculations for the justification of all principal stonework, units, fasteners, and anchorage components for compliance with the performance criteria established herein.

.3	Engineering Calculations: base calculations on design loads, material properties, and applicable safety factors. Include the following information as part of the calculations:
		.1	Stone loads and allowable loads,
		.2	Stone thicknesses,
		.3	Support and anchorage loads, stresses, safety factors, design loads, and allowable loads,
		.4	Support and anchorage sizes.

.4	Design connections and attachments for limestone to carry the design loads with safety factors and allowable stresses in accordance with the American Institute of Steel Construction (AISC), except that steel supports carrying gravity loads shall be stressed not more than 50 percent of the yield stress in bending.

.5	Design, detail and fabricate connections to provide allowance for fabrication tolerances, erection tolerances and structural deflections. Refer to ASTM C1242.

.6	Control of Corrosion: Prevent galvanic and other forms of corrosion by insulating metals and other materials from direct contact with non-compatible materials, or by suitable coating.

1.5			SHOP DRAWINGS

.1	Submit shop drawings [and setting diagrams] as specified in Section [01 00 00] [01 33 00] [______].

.2	Indicate sizes and sections of stone, arrangements of joints and bonding, anchoring, doweling and cramping.

.3	Each stone indicated on shop drawings must bear corresponding number marked on its back or bed or on the package labeling.

SPEC NOTE: Request analysis and testing reports only for larger projects, or where special conditions warrant the additional cost of such testing.

1.6			TESTING

.1	Submit [analysis] [and] [testing] of dimension stone as specified in Section [01 00 00] [01 04 00] [______].

.2	Testing: conduct tests on dimension stone for compressive strength and modulus of rupture.

.3	Test samples in accordance with indicated standards.

1.7			SAMPLES

SPEC NOTE: Edit the following two paragraphs for submission of physical samples for selection of finish, color, and/or texture.

.1	Submit samples as specified in Section [01 00 00] [01 33 00] [______].

.2	Submit [4] [6] [__] samples of limestone dimension stone to illustrate color and pattern range, and finish texture.

1.8			QUALITY ASSURANCE

.1	[Cladding Engineer: Professional engineer experienced in cladding design, registered to practice engineering in the Place of the Work.]

.2	Fabricator: Company having capacity to quarry, cut, and deliver the stonework on schedule.

.3	Installer: Company or person specializing in commercial masonry work [with 10 years [documented] experience]. Employ skilled stone fitters at the site to do necessary field cutting as stones are set.

.3	Obtain stone from a single quarry source with resources to provide materials of specified consistent quality.

1.9			MOCKUPS

.1	Construct mockup of stone cladding as specified in Section [01 00 00] [01 40 00] [______].

.2	Construct typical mockup panel [48” x 48”] [___ x ___] to illustrate stone, coursing or bond pattern, joints between units, and movement control joints.

.3	Construct mockup to illustrate [backup wall,] [exterior sheathing,] [air barrier,] [cavity wall insulation,] [connectors,] [weep holes,] [cavity vents,] [and] [through wall flashing].

.4	Mockup may [not] remain part of the finished Work.

1.10			DELIVERY, STORAGE AND HANDLING

.1	Refer to Section [01 00 00] [01 60 00] [______].

.2	Deliver and store stone in a manner designed to prevent damage and staining of units. Prevent damage to units.

.3	Lift skids with proper and sufficiently long slings or forks with protection to prevent damage to units. Protect edges and corners.

.4	Stack units on timbers or platforms at least 3” above grade.

.5	Place polyethylene or other non-staining plastic film between wood and other finished surfaces of units when stored for extended periods of time.

.6	Cover stored units with non-staining, weather-proof protective enclosure if exposed to weather.

.7	Do not use salt or calcium-chloride to remove ice from masonry surfaces.

1.11			ENVIRONMENTAL REQUIREMENTS

.1	Refer to Section [04 05 00] [______].

.2	Conform to requirements of TMS 602, PART 1.8.

2			Products

2.1			MANUFACTURERS

SPEC NOTE: In this article, list the manufacturers acceptable to the specifier. Consider including the name and telephone number of a local distributor to assist bidders with product sourcing. Also consider listing the acceptable Product adjacent to each manufacturer’s listing.

	.1	Manufacturers of dolomitic limestone having Product considered acceptable for use:
		.1	Arriscraft[, as distributed by [______]]; Adair® Limestone.

	.2	Substitution Procedures: Refer to [Instructions to Bidders] [and] [Section [01 00 00] [01 25 00] [______]].

2.2			MATERIALS

SPEC NOTE: Dimension limestone is classified by ASTM C568 into three categories, descriptive of the density of the stone, as follows:
Category I – Low-Density: 110 – 135 lb/ft3
Category II – Medium-Density: 135 – 160 lb/ft3
Category III – High-Density: > 160 lb/ft3

SPEC NOTE: Types of limestone are typically differentiated as either dolomite or calcarenite, depending on their chemical composition. Both types are sedimentary stones, containing a reed or grain running parallel to the natural bed. The difference between the two is largely reflected in the density and appearance of the stone.
•	Dolomitic limestone is a sedimentary carbonate rock consisting of more than 40 percent mineral dolomite, a calcium magnesium carbonate. It is generally very dense, and has a distinctively visible reed or grain.
•	Oolitic limestone is one type of calcarenite limestone, composed largely from the spherical or subspherical particles called oolites or ooliths, which are types of calcarenites. It is generally less dense than dolomitic limestone, and has a more uniform appearance, similar to sandstone.
•	Other types of limestone are also available, such as coquina, microcrystalline or travertine. Refer to ASTM C119 – Definitions of Terms Relating to Dimension Stone for further information regarding these types of limestone.

SPEC NOTE: Adair® Limestone Marble is a High-Density dolomitic limestone, capable of accepting a polished finish. As such, it may also be considered as a marble.

	.1	Dolomitic Limestone: to ASTM C568, Category III – High-Density; special shapes as indicated; having the following typical average properties when tested to the identified standard:
		.1	Compressive Strength: 22,900 psi, to ASTM C170.
		.2	Absorption: 0.75 percent, to ASTM C97.
			.3	Density: 167 lb/ft3, to ASTM C97.
			.4	Modulus of Rupture: 2,250 psi, to ASTM C99.
			.5	Flexural Strength: 1,600 psi, to ASTM C880.
			.6	Abrasion Resistance: 18.0, to ASTM C241.

SPEC NOTE: Refer to Arriscraft•DATA sheet 04 43 00 – Stone Masonry for specific information to sizes, finishes, colors, etc. If more than one type of unit is required, identify each separately by adding additional paragraphs as necessary.

2.3			FABRICATED UNITS

.1	Stone Panels: dolomitic limestone panels, as described below:
		.1	Bed Thickness: [1-1/4”] [2-1/8”] [____] thick.
		.2	Panel Sizes: modular sizes [as scheduled] [as indicated on Drawings].
		.3	Finish: [split] [bush hammered] [medium dressed] [fine dressed] [polished] finish on exposed faces [and ends].

SPEC NOTE: Split and bush hammered finishes available in 2-1/8” thickness only.
		.4	Color and Pattern: [Blue-Grey] [Sepia] color, [fleuried] [striated] pattern, to match approved sample range.
		.5	Product and Manufacturer’s Name: Adair® Limestone by Arriscraft.

.2	Sills and Trim: dolomitic limestone units, sizes and profiles as indicated on Drawings; [split] [bush hammered] [medium dressed] [fine dressed] [polished] finish on exposed faces [and ends]; [Blue-Grey] [Sepia] color, [fleuried] [striated] pattern, to match approved sample range.

2.4			ACCESSORIES

SPEC NOTE: Indicate type of anchorage required. i.e. stone panels anchored to masonry walls, stone panels anchored to concrete walls, etc. Ensure that drawings clearly indicate type of anchorage, number of anchors per each stone, and location. Refer to Arriscraft•NOTE (Vol. 1, No. 4), Connectors Part II – Dimension Stone Anchors.

.1	Anchors, Cramps, Dowels: to ASTM C1242, [yellow brass] [commercial bronze] [stainless steel, Type [304] [316] [___]]; as specified in Section [04 05 19] [______].

.2	[Seismic] Bed Reinforcement: as specified in Section [04 05 19] [______].

.3	Setting Buttons: [lead] [resilient plastic] [_____] type; non-staining; sized to suit joint thicknesses and bed depths without intruding into required depths of joint sealants or causing third-side adhesion between sealant and setting button.

.4	Seismic Clips: purpose made clips designed to secure bed joint reinforcement to the structural substrate’s joint reinforcement system as a composite element and allow in-plane vertical and horizontal movement while restraining lateral movement; [_____] manufactured by [______].

	.5	Through-Wall Flashing: as specified in Section [04 05 23] [______].

.6	Mortar: as specified in Section [04 05 10] [______].

	.7	Grout: as specified in Section [04 05 16] [______].
 
	.8	Weep Vents: as specified in Section [04 05 23] [______].

	.9	Sealant and Backer Rod: as specified in Section [07 92 00] [______].

2.5			FABRICATION

.1	Cut stone to shape and dimensions and full to square with joints as indicated.

	.2	Dress exposed faces true.

.3	Cut-in reglets for flashings where indicated.

.4	Execute profiled work from full size details and templates.

.5	Make exposed arrises in true alignment and ease slightly to prevent snipping.

.6	Back-check stone contacting structural members as indicated. Allow minimum 1” clearance between back of stone and steel and concrete structural members. Shape beds of stone resting on structural work to fit supports.

.7	Cut stones for anchors, cramps, dowels and support systems. Provide lewis pin and clamp holes in pieces which can not be manually lifted. Do not cut holes in exposed surfaces.

.8	Finish exposed faces and edges of stones to comply with requirements indicated for finish and to match approved samples and field-constructed mockup.

2.6			FABRICATION TOLERANCES

	.1	Except where dimension stone is formed by a split finish, fabricate limestone dimension stone to the following tolerances:
		.1	Unit Length: plus or minus 1/8”.
		.2	Unit Height: plus or minus 1/8”.
		.3	Deviation From Square: plus or minus 1/8”, with measurement taken using the longest edge as the base.
		.4	Bed Depth: plus or minus 1/8”.

3			Execution

3.1			PREPARATION

.1	Apply asphalt emulsion to concrete surfaces, shelf angles, structural steel supports against which stone is to be applied.

.2	Clean stone surfaces by washing with stiff fiber brush and water.

3.2			SETTING STONE – GENERAL

.1	Set stones plumb, true, and level, to requirements indicated on drawings and approved shop drawings.

.2	Align stone edges and faces according to established relationships and indicated tolerances.

.3	Provide movement joints of widths and at locations indicated on drawings. [Do not fill movement joints with mortar.]

3.3	SETTING STONE WITH MORTAR

.1	Set stones in full bed of mortar with vertical joints buttered and placed full, except where otherwise specified. Completely fill anchor, dowel and lifting holes.

.2	Lay stone panel cladding to patterns indicated on Drawings. Install anchors, dowels and cramps. Shim and adjust supports to set stones accurately in locations indicated with uniform joints of widths indicated.

.3	Make joints [1/4] [3/8] [1/2] inch thick.

.4	Embed only ends of lugged sills and steps in mortar. Leave balance of joint open for final pointing.

.5	Place [setting buttons] [soft-wood wedges] under stones to maintain joint thickness. Set heavy stones and projecting courses after mortar in courses below has hardened sufficiently to support weight.

.6	Brace and anchor projecting stones until wall above is set.

.7	Use [soaked softwood wedges] to support stone in proper alignment until mortar has set. [Remove wedges when dry and without breaking them off, fill voids with pointing mortar.]

.8	Install through-wall flashing membranes at continuous shelf angles, steel lintels, ledges and similar obstructions to the downward flow of water.

SPEC NOTE: Ensure that drawings indicate location and spacing of weep holes.

	.9	Install weep vents at [24”] [____] o.c. horizontally [above through-wall flashing] [above shelf angles], [and] [at bottom of walls] [_____].

SPEC NOTE: Consider the effects of venting all cavity compartments to ensure proper pressure equalization and ventilation.

	.10	Install cavity vents at [top of cavity space] [_____] at same spacing.

	.11 Tool joints after initial set has occurred.

[OR]

	.11	Rake out joints to [1”] [____] depth and make ready for pointing with [pointing mortar] [sealant]. Sponge stone face along joints and remove droppings and splashed mortar immediately.

	.12	Set [cornices,] [copings,] [projecting belt courses,] [steps] [and] [platforms] with unfilled vertical joints.

	.13	Grouting:
		.1	Pack ends of exposed joints with plastic foam joint filler and after wetting ends of stone, fill joint with grouting mortar to within 3/4" of top.
		.2	Grout vertical joints of [cornices,] [copings,] [projecting belt courses,] [steps] [and] [platforms].
		.3	After grout has set, remove packing for pointing.

	.14	Pointing:
		.1	Remove dirt and loose mortar from joints by using pressurized air stream.
		.2	Wet joints for mortar pointing. Dry joints for sealant pointing.
		.3	Point joints with pointing mortar in [two] [three] stages. Rub smooth with appropriate tool to slightly concave joint.

SPEC NOTE: Insert joint locations requiring sealant pointing, usually for projecting stones and top joints of copings.

		.4	Point [coping] [sill] [_____] joints with sealant. Conform to Section [07 92 00] [______].

3.4	SETTING STONE WITH SEALANT JOINTS

.1	Attach anchors, dowels and cramps securely to stone and back-up surfaces.

.2	Shim and adjust supports to set stones accurately in locations indicated with uniform joints of widths indicated.

.3	Completely fill anchor, dowel and lifting holes with sealant. Where dowel holes occur at movement joints, install compressive material above and below dowels.

.4	Make joints [1/4] [3/8] [1/2] inch thick.

.5	Place [setting buttons] [soft-wood wedges] under stones to maintain joint thickness. Locate [buttons] [wedges] back from face of stone to provide space for sealant application as described in Section [07 92 00] [______].

.6	Brace and anchor projecting stones until wall above is set.

.7	Install through-wall flashing membranes at continuous shelf angles, steel lintels, ledges and similar obstructions to the downward flow of water.

SPEC NOTE: Ensure that drawings indicate location and spacing of weep holes.

	.8	Install weep vents at [24”] [___] o.c. horizontally [above through-wall flashing] [above shelf angles], [and] [at bottom of walls] [_____].

SPEC NOTE: Consider the benefits of venting all cavity compartments to ensure proper pressure equalization and ventilation.

.9	Install cavity vents at [top of cavity space] [_____] at same spacing.

.10	Seal joints with backer rods and joint sealant as specified in Section [07 92 00] [______].

3.5			SITE TOLERANCES

.1	Variation from Plumb: plus or minus 1/4" per 10 feet maximum.

.2	Variation from Level: plus or minus 1/2" per 20 feet maximum.

.3	Variation from Linear Building Line: plus or minus 1/2" per 20 feet maximum.

.4	Variation in Cross-Sectional Dimensions: plus 1/2" or minus 1/4".

3.6			FIELD QUALITY CONTROL

	.1	Perform inspection and testing as specified in Section [01 00 00] [01 40 00] [______].

	.2	[Architect] [Consultant] Inspection: [Architect] [Consultant] will inspect installed dimension stone and reject stone that is chipped, cracked, or blemished (streaked, stained or otherwise damaged), as described below.
		.1	Stone will be inspected to be free of cracks or other blemishes on the finished face or front edges of the masonry units exceeding 3/8 inch or that can be seen from a distance of 20 feet.
		.2	Units shall exhibit a texture approximately equal to the approved sample when viewed under diffused daylight illumination at a 20 foot distance.
		.3	Minor chipping resulting from shipment and delivery shall not be grounds for rejection. Minor chips shall not be obvious under diffused daylight illumination from a 20 foot distance.
		.4	Dry seams and natural vugs will not be cause for rejection.

	.3	Make Good rejected masonry as directed by [Architect] [Consultant].

3.7			ADJUSTING AND CLEANING

.1	Refer to Section [01 00 00] [01 74 00] [______].

	.2	Repair chips with patch kits furnished by manufacturer.

	.3	Clean stone as work progresses.

	.4	Allow mortar droppings on stone to partially dry then remove by means of brushing with a stiff fiber brush.

SPEC NOTE: Select one of the following Paragraphs. Edit as recommended by dimension stone manufacturer’s recommendations. Refer to Arriscraft•NOTE (Vol. 2, No. 1), Cleaning Masonry.

	.5	Clean [a 100 square foot area of wall designated by [Architect] [Consultant]] [one-half of mock-up panel] as directed below and leave for one week. If no harmful effects appear, all objectionable stains removed and after mortar has set and cured, clean masonry as follows:
		.1	Protect windows, sills, doors, trim and other work from damage.
		.2	Remove large particles with [stiff fiber brushes] [wood paddles] without damaging surface.
		.3	Saturate masonry with clean water and flush off loose mortar and dirt.
		.4	Dilute cleaning agent with clean water in controlled proportions.
		.5	Apply solution to pre-soaked wall surface using [soft-bristled brush] [low pressure acid-resistant sprayer].
		.6	Thoroughly rinse cleaning solution and residue from wall surface.

	.6	Use alternative cleaning solutions and methods for difficult to clean stone only after consultation with stone manufacturer.

3.8			PROTECTION

	.1	Protect stone from damage resulting from subsequent construction operations.

	.2	Use protection materials and methods which will not stain or damage stone.

	.3	Remove protection materials upon Substantial Performance of the Work, or when risk of damage is no longer present.

SPEC NOTE: Consider the inclusion of a dimension stone schedule when multiple sizes, finishes and colors are to be used. Ensure stone type locations are clearly identified on the drawings.

3.9			SCHEDULE

.1	Following is a schedule of shapes, sizes and finishes to be used on this Project:
		.1	Type A: [_____].
		.2	Type B: [_____].

END OF SECTION