Attachment_20_-_Section_09_64_66_Athletic_Wood_Flooring.pdf

FA4419-14-R-0102

Attachment 20

SECTION 09 64 66

WOOD ATHLETIC FLOORING

PART 1 GENERAL

1.1 REFERENCES

1.2 SUBMITTALS

1.3 SUSTAINABLE DESIGN CERTIFICATION

1.4 DELIVERY, STORAGE, AND HANDLING

1.5 ENVIRONMENTAL CONDITIONS

PART 2 PRODUCTS

2.1 HARDWOOD STRIP FLOORING SYSTEMS ON CONCRETE SLAB

2.1.1 Clipped to Steel Channels on Underlayment

2.1.2 Wood Sleepers with Rubber Cushions

2.1.3 Wood Board Subflooring, Wood Nailers, and Asphalt Fill

2.1.4 Plywood Subflooring with Rubber Pads

2.1.5 Steel-Splined, Continuous Unit, [on Cork Underlayment]

2.2 MATERIALS

2.2.1 Strip Flooring

2.2.2 Hardwood Base

2.2.3 Molded-Rubber Base

2.2.4 Steel Angle Base

2.2.5 Steel Channels and Clips

2.2.6 Fiberboard Underlayment

2.2.7 Rubber Cushions and Pads

2.2.8 Flexible Foam Underlayment

2.2.9 Polyethylene Vaporproofing Membrane

2.2.10 Asphalt Primer

2.2.11 Asphalt Mastic

2.2.12 Asphalt Fill

2.2.13 Felt

2.2.14 Building Paper

2.2.15 Sleepers and Nailers

2.2.16 Wood Board Subflooring

2.2.17 Plywood Subflooring

2.2.18 Sealing and Finishing for Hardwood Strip Flooring

2.2.19 Game Line Marking Materials

2.2.20 Nails

2.2.21 Underlayment

2.2.22 Adhesives

PART 3 EXECUTION

3.1 PREPARATION

3.1.1 Condition of Subfloors

3.1.2 Preparation of Concrete Slab

3.1.3 Anchor Plate Assemblies for Portable Sports Equipment

3.1.4 Work of Other Trades

3.1.5 Moisture Content

3.2 INSTALLATION

3.2.1 Vaporproofing For Slabs on Grade

3.2.2 Flooring Clipped to Steel Channels

3.2.2.1 Channel Placing

3.2.2.2 Laying of Finished Flooring

3.2.3 Flooring on Wood Sleepers with Rubber Cushions

3.2.3.1 Installation of Wood Sleepers With Rubber Cushions

3.2.3.2 Laying of Finished Flooring

3.2.4 Flooring on Board Subflooring, Wood Nailers, and Asphalt Fill

3.2.4.1 Priming of Concrete Slab

3.2.4.2 Wood Nailers

3.2.4.3 Asphalt Fill

3.2.4.4 Wood Board Subflooring

3.2.4.5 Felt

3.2.4.6 Laying of Finished Flooring

3.2.5 Flooring on Plywood Subflooring With Rubber Pads

3.2.5.1 Installation of Plywood Subflooring With Rubber Pads

3.2.5.2 Laying of Finished Flooring

3.2.6 Flooring, Continuous Steel-Splined, [on Cork Underlayment]

3.2.6.1 Vaporproofing for Slabs on Grade

3.2.6.2 Cork Underlayment

3.2.6.3 Finished Flooring

3.2.7 Hardwood Base Installation

3.2.8 Molded-Rubber Base Installation

3.2.9 Steel Angle Base Installation

3.3 SANDING, FINISHING, AND MARKING

3.3.1 Sanding

3.3.2 Finishing

3.3.3 Marking

3.4 PROTECTION

3.5 SCHEDULE

-- End of Section Table of Contents --

SECTION 09 64 66

WOOD ATHLETIC FLOORING

PART 1 GENERAL

1.1 REFERENCES

The publications listed below form a part of this specification to the extent referenced. The publications are referred to within the text by the basic designation only.

AMERICAN WOOD PROTECTION ASSOCIATION (AWPA)

AWPA C1 (2003) All Timber Products – Preservative Treatment by Pressure

Processes

AWPA C2 (2003) Lumber, Timber, Bridge Ties and Mine Ties - Preservative

Treatment By Pressure Processes

AWPA M4 (2011) Standard for the Care of Preservative-Treated Wood

Products

ASTM INTERNATIONAL (ASTM)

ASTM A36/A36M (2012) Standard Specification for Carbon Structural Steel

ASTM C208 (2012) Cellulosic Fiber Insulating Board

ASTM D1622 (2008) Apparent Density of Rigid Cellular Plastics

ASTM D2103 (2010) Standard Specification for Polyethylene Film and Sheeting

ASTM D2240 (2005; R 2010) Standard Test Method for Rubber Property - Durometer

Hardness

ASTM D226/D226M (2009) Standard Specification for Asphalt-Saturated Organic Felt

Used in Roofing and Waterproofing

ASTM D395 (2003; R 2008) Standard Test Methods for Rubber Property - Compression

Set

ASTM D41/D41M (2011) Asphalt Primer Used in Roofing, Dampproofing, and

Waterproofing

ASTM D412 (2006a; R 2013) Standard Test Methods for Vulcanized Rubber and

Thermoplastic Elastomers - Tension

ASTM D449 (2003; R 2008) Asphalt Used in Dampproofing and Waterproofing

ASTM E96/E96M (2012) Standard Test Methods for Water Vapor Transmission of

Materials

ASTM F36 (1999; R 2009) Compressibility and Recovery of Gasket Materials

MAPLE FLOORING MANUFACTURERS ASSOCIATION (MFMA)

MFMA AFSFSCL (2003) Athletic Floor Sealer and Finish Specifications and

Conformance List #22

MFMA GRHM (2000) Grading Rules for MFMA Northern Hardwood Maple

MFMA SSCLFMGF (2000) Sanding, Sealing, Court Lining, Finishing and Resurfacing of Maple Gym Floors

SCIENTIFIC CERTIFICATION SYSTEMS (SCS)

SCS Scientific Certification Systems (SCS)Indoor Advantage

UL ENVIRONMENT (ULE)

ULE Greenguard UL Greenguard Certification Program

1.2 SUBMITTALS

Government approval is required for submittals with a "G" designation; submittals not having a

"G" designation are [for Contractor Quality Control approval.][for information only. When used, a designation following the "G" designation identifies the office that will review the submittal for the Government.] The following shall be submitted in accordance with Section 01 33 00

SUBMITTAL PROCEDURES:

SD-02 Shop Drawings

Hardwood strip flooring system

Clearly delineate components of the system. Show layout of [sleepers]

[steel channels] [steel spines]; location of anchor plate assemblies, floor outlets, and underfloor conduit or raceway location; flooring system details; and flooring abutting other construction.

Accessories shall be approved by the flooring manufacturer.

SD-03 Product Data

Hardwood strip flooring components

Certification

SD-04 Samples

Strip flooring[; G][; G, [_____]]

Hardwood base[; G][; G, [_____]]

Molded-rubber base[; G][; G, [_____]]

Steel channels and clips

[ Fiberboard underlayment]

[ Flexible foam underlayment]

Cushions and pads

Corkboard or corkroll

Sleepers and nailers

SD-06 Test Reports

Preservative treatment

SD-08 Manufacturer's Instructions

Flooring system

Adhesive for membrane installation

Submit flooring system manufacturer's installation instructions. Submit vaporproofing manufacturer's written recommendations for adhesives to be used in membrane installation.

SD-10 Operation and Maintenance Data

Hardwood strip flooring, Data Package 1; [; G][; G, [_____]]

Submit in accordance with Section 01 78 23 OPERATION AND

MAINTENANCE DATA.

1.3 SUSTAINABLE DESIGN CERTIFICATION

Product shall be third party certified in accordance with ULE Greenguard[ Gold], SCS Scientific

Certification Systems Indoor Advantage[ Gold ]or equal. Certification shall be performed annually and shall be current.]

1.4 DELIVERY, STORAGE, AND HANDLING

Deliver materials to the building site in original unopened packages, bundles, or containers.

Protect materials against dampness during shipment and after delivery. Store material under cover in a well-ventilated building. Prevent exposure to extreme changes of temperature and humidity. Do not store materials in building under construction until wet-applied building materials are dry. Store flooring in accordance with MFMA GRHM, under adequate and controlled ventilation and under approved temperature and humidity conditions at the location where it is to be laid for at least 7 days before installation. Handle and store preservative-treated material in accordance with AWPA M4.

1.5 ENVIRONMENTAL CONDITIONS

For at least one week prior to and during installation, in the location to receive finish flooring and the location where flooring will be stored, maintain a temperature of between 65 and 80 degrees F, and a relative humidity of between 40 and 60 percent. When the interior relative humidity exceeds 60 percent during or after installation of flooring, sanding and finishing of flooring shall be delayed for 2 to 3 weeks after completion of laying, unless directed otherwise.

Provide adequate ventilation during the entire sealing and finishing process to ensure that no unhealthy or hazardous accumulation of vapors occurs. Ensure that environmental conditions are met.

PART 2 PRODUCTS

2.1 HARDWOOD STRIP FLOORING SYSTEMS ON CONCRETE SLAB

2.1.1 Clipped to Steel Channels on Underlayment

Provide flooring system consisting of hardwood strip flooring clipped to steel channels that rest in premilled grooves in [fiberboard] [flexible foam] underlayment. Anchor steel channels to concrete floor slab.

2.1.2 Wood Sleepers with Rubber Cushions

Provide flooring system consisting of hardwood strip flooring nailed to wood sleepers that are seated on rubber cushions resting on the concrete floor slab.

2.1.3 Wood Board Subflooring, Wood Nailers, and Asphalt Fill

Provide flooring system consisting of hardwood strip flooring nailed to wood board subflooring that is, in turn, nailed to shimmed wood nailers anchored to the concrete floor slab. Provide hot asphalt fill under and between the wood nailers.

2.1.4 Plywood Subflooring with Rubber Pads

Provide flooring system consisting of hardwood strip flooring nailed to two-layer plywood subflooring that is seated on cushioned pads resting on the concrete floor slab.

2.1.5 Steel-Splined, Continuous Unit, [on Cork Underlayment]

Provide flooring system consisting of uniform lengths of hardwood strip flooring interlocked with steel splines and laid in asphalt mastic [on cork underlayment which is laid in asphalt mastic over membrane of felt] on the concrete floor slab.

2.2 MATERIALS

2.2.1 Strip Flooring

Second or better grade [hard maple] [beech or birch] graded in accordance with current

MFMA GRHM. Flooring shall be [25/32][33/32] [_____] inch thick by [2 1/4] [1 1/2] inches or narrower on the face, kiln dried, continuous tongue-and-groove, and end-matched. Each bundle of flooring shall be clearly grade stamped. Moisture content of strip flooring shall not exceed 8 percent at time of arrival on job site and shall be allowed to acclimate in accordance with paragraph entitled "Delivery, Storage, and Handling."

[Flooring for steel-splined systems shall be edge-grain 33/32 inch thick by 1 5/16 inch on the face, kiln-dried, continuous tongue-and-groove, and end grooved.]

2.2.2 Hardwood Base

Clear [hard maple] [beech or birch]. Provide shape and size of base as indicated or as recommended by the flooring manufacturer.

2.2.3 Molded-Rubber Base

4 inch vertical leg by 3 inch, designed to allow ventilation under floor, and as recommended by flooring manufacturer.

2.2.4 Steel Angle Base

Provide 3 by 3 by 3/16 inch continuous steel angle along perimeter walls, designed to allow ventilation under the floor. Base angle shall conform to ASTM A36/A36M.

2.2.5 Steel Channels and Clips

Provide channels and clips not less than thick 16 gage zinc-coated steel.

2.2.6 Fiberboard Underlayment

ASTM C208, fiberboard insulation board, impregnated with asphalt or coated with asphalt on faces and edges, treated for termite and water resistance.

2.2.7 Rubber Cushions and Pads

Rubber cushions and pads shall have a durometer hardness of A50, plus or minus 5, when tested in accordance with ASTM D2240 and shall have a minimum tensile strength of

1500 psi, when tested in accordance with ASTM D412. When subjected to an aging period of 70 hours and exposed to a temperature of 158 degrees F, allowed to cool to room temperature over a period of 4 hours and retested, tested specimen shall have a change in hardness of 10 points maximum, a change in tensile strength of minus 25 percent maximum and a change in ultimate elongation of minus 25 percent maximum in accordance with the applicable test methods referenced above. Test rubber cushions, under a load of 40 psi, in accordance with ASTM D395, Method A. Size of tested specimen shall be 2 1/4 by 3 by 3/8 inch. Length of testing time shall be 22 hours;

temperature of test shall be 158 degrees F. Test specimen shall recover, without set or displacement.

2.2.8 Flexible Foam Underlayment

Multicellular, closed cell flexible polyethylene plastic foam having smooth skin; density

1.7 to 3.3 pounds per cubic footwhen tested by ASTM D1622. Foam shall be 1/2 inch thick by 48 inches wide by manufacturer's standard length, premilled to receive steel channels at 12 inch centers.

2.2.9 Polyethylene Vaporproofing Membrane

ASTM D2103 Type 21110. Minimum thickness shall be 6 mils. Perm rating shall not exceed 0.02 when tested in accordance with ASTM E96/E96M.

2.2.10 Asphalt Primer

ASTM D41/D41M.

2.2.11 Asphalt Mastic

As recommended by the flooring manufacturer.

2.2.12 Asphalt Fill

ASTM D449, Type I.

2.2.13 Felt

ASTM D226/D226M, type I, asphalt-saturated organic felt.

2.2.14 Building Paper

Water-vapor permeable, 20 lb per inch dry tensile strength.

2.2.15 Sleepers and Nailers

Surfaced on four sides, 2 by 3 inches nominal size, Standard or No. 2 grade douglas fir, northern or western and west coast hemlock, engleman-spruce or No. 2 dimension southern pine. Moisture content shall not exceed 15 percent. Provide preservative treatment in accordance with [ AWPA C1] [AWPA C2]. Identify treatment on each piece of material by the quality mark of an agency accredited by the Board of Review of the

American Lumber Standard Committee. Brush coat exposed areas that are cut or drilled after treatment with the same preservative in accordance with AWPA M4.

2.2.16 Wood Board Subflooring

No. 2 common douglas fir, northern or western hemlock, englemann spruce, or southern pine No. 2 boards, northern red or Norway pine, surfaced on four sides. Nominal sizes shall be 1 by 6 inches or 1 by 4 inches. Moisture content shall not exceed 15 percent.

2.2.17 Plywood Subflooring

Douglas fir, southern pine, or western larch plywood; grade C-D, with exterior glue; 1/2 inch thick by 4 by 8 feet.

2.2.18 Sealing and Finishing for Hardwood Strip Flooring

Conform to MFMA AFSFSCL, Group [II] [III] finish. Seal coat and finish coat materials shall be compatible with each other.

2.2.19 Game Line Marking Materials

As recommended by wood flooring finish manufacturer.

2.2.20 Nails

Shape and size as recommended by flooring manufacturer.

2.2.21 Underlayment

Corkboard or corkroll, 13 mm 1/2 inch thick, conforming to ASTM F36.

2.2.22 Adhesives

Waterproof, suitable for use with molded rubber base, recommended by rubber base manufacturer.

PART 3 EXECUTION

3.1 PREPARATION

3.1.1 Condition of Subfloors

Do not install flooring on surfaces that are not suitable for proper installation. Before beginning work under this section, correct defects such as rough or scaling concrete, low spots, high spots, uneven surfaces, and repair damaged portions of concrete slabs.

Concrete slabs shall be given a leveling course of latex fill and the surface shall not vary more than 1/8 inch when measured with a 10 foot straightedge placed in any direction.

3.1.2 Preparation of Concrete Slab

Sweep concrete floor. Ensure that slab is dry and clean. Remove paint spots, plaster, masonry droppings, grease, dirt, and other foreign matter [including chemical curing agents which may affect the bond of adhesive-applied wood flooring systems]. Concrete shall be fully cured and dry.

3.1.3 Anchor Plate Assemblies for Portable Sports Equipment

Floor anchor plate assemblies for vertically adjustable portable sports equipment shall be installed where indicated. Flooring shall be cut neatly around floor plates.

3.1.4 Work of Other Trades

Do not start work specified under this section until work of trades which could create moisture, has been completed.

3.1.5 Moisture Content

Check flooring, subflooring, sleepers and nailers with an approved meter verifying conformance with the requirements specified hereinbefore.

3.2 INSTALLATION

3.2.1 Vaporproofing For Slabs on Grade

Cover slab with the polyethylene membrane. Lap joints at least 6 inches. Seal joints with a full coverage of the adhesive recommended by the membrane manufacturer.

3.2.2 Flooring Clipped to Steel Channels

3.2.2.1 Channel Placing

Install each channel in premilled grooves spaced 12 incheson center in

[fiberboard] [flexible foam] parallel to the short side of the room, with butted end-to-end joints staggered at least 24 inches. Anchor channels to the slab at 14 inches on center with 3/8 inch diameter, flat headed anchors that penetrate the slab by at least 1-1/4 inches. Set channels level.

3.2.2.2 Laying of Finished Flooring

Lay finished flooring at right angles to the steel channels. Begin installation with double-tongue strips of flooring in center of room. Clip each board down tightly at each channel intersection with zinc-coated flooring clips. Each clip shall firmly engage the side edges of the flooring and the steel channels. Ensure that each clip is placed properly.

Stagger adjacent end joints of flooring so that there will be at least two boards between joints. Where floor plates occur, install steel channels along edges of flooring board; provide clips for flooring. Drive each flooring strip up sideways and endways as tightly as practicable using steel driving tools that prevent marring of exposed flooring. Boards shall be scribed to permanent obstructions and securely blocked at wall lines.

3.2.3 Flooring on Wood Sleepers with Rubber Cushions

3.2.3.1 Installation of Wood Sleepers With Rubber Cushions

Install rubber-cushioned wood sleepers, [ 12 inches on center for 33/32 inch] [ 9 inches on center for 25/32 inch] thick flooring, parallel to short side of the room, with butted end-to-end joints, 1/4 inch apart at the joints, staggered at least 24 inches. Sleepers shall have the rubber cushions attached at 12 inch centers.

Provide a 2 inch air space between ends and sides of sleepers at walls and other permanent obstructions. Sleepers shall be seated level and firm with rubber cushions bearing completely on the subfloor. [In areas where fixed or temporary seats are indicated, provide 1-5/8 by 1-7/8 inch wood screeds midway between the cushioned wood sleepers.]

3.2.3.2 Laying of Finished Flooring

Begin installation of flooring in center of space with double-tongue strips of flooring. Lay flooring at right angles to the wood sleepers. Blind nail each strip of flooring to each wood sleeper with 8 penny spiral screw nails. Leave a continuous air space, 2 inches wide, between finished flooring and perimeter walls and other permanent obstructions. Stagger end joints of adjacent strips of flooring so that there will be at least two boards between each joint.

3.2.4 Flooring on Board Subflooring, Wood Nailers, and Asphalt Fill

3.2.4.1 Priming of Concrete Slab

Prime slab with asphalt primer using minimum of one gallon per 250 square feet.

Allow primer to dry.

3.2.4.2 Wood Nailers

Install continuous 2 by 3 inch nominal size wood nailers 12 inches on center, parallel to short side of room, with butted end-to-end staggered joints, 1/4 inch apart at the joints. Elevate bottoms of nailers about 3/16 inch above concrete slab with fiber shims. Fasten nailers to slab with 1/4 by 3 1/2 inch power driven anchors spaced 30 inches on center and staggered in adjacent rows. Provide an additional anchor not more than 6 inches from the end of each nailer. Provide a 2 inch air space between ends and sides of sleepers at walls and other permanent obstructions. Nailers shall be set level and in alignment. Check level of tops of nailers with a surveyor's instrument.

3.2.4.3 Asphalt Fill

When the wood nailers have been set and leveled, pour the hot asphalt over the entire concrete slab surface; fill the spaces under the wood nailers completely and cover the concrete slab surface between the nailers to a depth of approximately

3/8 to 1/2 inch. Pour asphalt up 1/4 inch on the sides of the nailers.

3.2.4.4 Wood Board Subflooring

Apply wood subflooring diagonally over the wood nailers. Cut ends parallel to and over center lines of wood nailers. Nail subflooring securely to each wood nailer with 7 penny steel spiral screw nails; use two nails for 4 and 6 inch wide boards. Space boards approximately 1/8 inch apart. Top of subflooring shall have a true, even plane. Provide 2 inches of clearance between subflooring and perimeter walls and other permanent obstructions.

3.2.4.5 Felt

Cover wood subflooring with a layer of the felt. Butt edges tightly. Do not extend felt over air space between ends and sides of finished floor and perimeter walls or other permanent obstructions.

3.2.4.6 Laying of Finished Flooring

Begin installation of flooring in center of space with double-tongue strips of flooring. Lay flooring at right angles to the wood nailers and parallel with the long dimension of the room. Blind nail each strip of flooring through the subflooring and into the sleeper with 8 penny screw type nails, spaced not over 12 inches apart over the sleepers. Leave a continuous air space 2 inches wide between the finished flooring and perimeter walls and other permanent obstructions. Stagger end joints of adjacent strips of flooring so that there will be at least two boards between each joint.

3.2.5 Flooring on Plywood Subflooring With Rubber Pads

3.2.5.1 Installation of Plywood Subflooring With Rubber Pads

Provide two layers of 1/2 inch thick plywood sheets, of 4 by 8 feet. Each 4 by 8 foot sheet in the bottom layer bearing on slab shall have 32 rubber pads, 2-1/4 by

3 by 3/8 inch thick, approximately 12 inches on center in each direction, stapled to underside of sheet. Partial sheets shall have rubber pads 12 inches on center and at perimeters. Lay first layer of plywood on concrete floor slab, parallel to short side of room. Lay second layer at a 45 degree angle to first layer and fasten it to first layer by machine nailing or stapling on 24 inch centers using one inch nails or staples. Leave a continuous air space 50 mm 2 inches wide between the subflooring and perimeter walls and other permanent obstructions and 1/4 inch between panels at sides and ends. Lap panels so that no joint will fall over any joint of the first layer. [In areas where fixed or temporary seats are indicated, provide fixed hardboard shims,1/8 inch thick, between the cushioned pads.]

3.2.5.2 Laying of Finished Flooring

Begin installation of flooring in center of space with double-tongue strips of flooring. Lay flooring parallel with the long dimension of the room. Flooring shall be blind nailed on 10 inch centers with 1-3/4 inch spiral screw nails. Leave a continuous air space, 2 inches wide, between the finished flooring and perimeter walls and other permanent obstructions. Stagger end joints of adjacent strips of flooring so that there will be at least two boards between each joint. [Roller skating rink flooring shall be 33/32 inch thick or 25/32 inch and laid in special octagonal pattern as indicated.

Diagonal intersections of flooring shall be joined with barbed steel splines.]

3.2.6 Flooring, Continuous Steel-Splined, [on Cork Underlayment]

3.2.6.1 Vaporproofing for Slabs on Grade

Prime concrete slab with asphalt primer using a minimum of one gallon per 250 square feet. Following application and drying of the primer apply a membrane of two layers of felt. Lay each layer of felt in a coating of trowelled asphalt mastic, applied at the rate of at least one gallon per 35 square feet. Felts shall be butted at joints. Turn up felt 1-1/2 inches at perimeter walls and other permanent obstructions. Roll felt thoroughly, eliminating air pockets and blisters, to provide an overall smooth and level surface. Cover top layer of felt with a coating of trowelled asphalt mastic applied at the rate of at least one gallon per 35 square feet.

3.2.6.2 Cork Underlayment

Install underlayment in asphalt mastic. Provide a 1/16 inch space at joints of corkboard. After underlayment has been installed, roll entire area with a 150 pound roller to attain maximum bond and a uniformly even surface. Leave a 1-1/2 inch air space between underlayment and perimeter walls and other permanent obstructions.

3.2.6.3 Finished Flooring

Lay 12 inch long strips of finished flooring firmly in full bed of asphalt mastic in end-to-end courses, interlocking with saw-tooth steel splines into the slotted ends.

Break joints of continuous strip units in succeeding courses. Lay continuous strip units parallel with the width of the room. Lay flooring level and in correct alignment. Leave a continuous air space, 1-1/2 inches wide, between the finished flooring and perimeter walls and other permanent obstructions. Lay flooring with hairline joints. Do not drive flooring up tightly.

3.2.7 Hardwood Base Installation

Install molded and perforated continuous hardwood base of the type indicated, along perimeter walls. Base shall have 3/8 inch diameter vent holes spaced 5 inches on center in a straight row. Nail or bolt base to wall. Do not fasten base to flooring.

3.2.8 Molded-Rubber Base Installation

Install molded-rubber base firmly on perimeter walls in continuous adhesive as recommended by the base manufacturer. Provide vertical, circular or semicircular vent holes in base spaced 5 inches on center in a straight row. Do not fasten base to flooring.

3.2.9 Steel Angle Base Installation

Install 3 by 3 by 3/16 inch continuous steel angle along perimeter walls. Bottom leg of angle shall have 3/8 inch diameter vent holes spaced 5 inches on center in a straight row.

Fasten angle to wall at intervals of 16 inches with countersunk head [expansion] [toggle] bolts. Do not fasten angle to flooring.

3.3 SANDING, FINISHING, AND MARKING

3.3.1 Sanding

Sand wood floor surfaces with a machine using coarse, medium, and fine grades of sandpaper; the edges shall be sanded to a smooth edge; the finished surface shall be smooth and level, free from scratches. A final disc sanding shall be provided. After final sanding or buffing, vacuum floors until clean. Do not walk on floors thereafter until finish has been applied and is dry.

3.3.2 Finishing

[Finishing shall be provided as specified in [_____].] [Within one day after the final sanding, buffing, and sweeping have been completed, use a tacky rag to clean flooring with a solvent recommended by the manufacturer of the floor finish material. Follow cleaning with a coating of sealer; when thoroughly dry, burnish with No. 2 steel wool, using a power machine. After final burnishing and prior to application of final finish coat(s), layout and mark game lines as specified herein; after game lines are thoroughly dry, apply final finish coat.] Floors shall be wiped with a tacky rag each burnishing.

[Finish floors in accordance with MFMA SSCLFMGF. Four Coat Specification: Group II finish shall consist of one sealer coat and three finish coats. Group III finish shall consist of two sealer coats and two finish coats. Allow 5 days for proper curing.]

3.3.3 Marking

Lay out game lines and fields [and patterns] where indicated, masking edges to provide sharp, clean edges. Edge shall be straight and width shall be uniform. Apply marking of colors indicated, providing a minimum dry film thickness of one mil.

3.4 PROTECTION

After completion of laying, finishing, and marking of the flooring, do not use the floor for at least 72 hours. Avoid heavy traffic on the floor for at least one week. Upon floor drying, use nonstaining, porous building paper of the type and grade recommended by manufacturer, taped along edges. Remove kraft paper covering after work in this area is completed.

-- End of Section --