Attachment 8 - Spec. 07920 Sealants.doc

USDA, NCAH, AMES, IA - BUILDING 7 - SUITE 3 FLOOR COATING REPAIR

SECTION 07920 Page 1

PART 1 GENERAL

REFERENCES

SECTION 07920

JOINT SEALANTS

10/03

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.

ASTM INTERNATIONAL (ASTM)

ASTM C 509 (2000) Elastomeric Cellular Preformed Gasket and Sealing Material

ASTM C 734 (2001) Low-Temperature Flexibility of Latex Sealants After Artificial Weathering

ASTM C 919 (2002) Use of Sealants in Acoustical Applications

ASTM C 920 (2002) Elastomeric Joint Sealants

ASTM D 1056 (2000) Flexible Cellular Materials - Sponge or Expanded Rubber

ASTM D 217 (2002) Cone Penetration of Lubricating Grease

ASTM E 84 (2004) Surface Burning Characteristics of Building Materials

SUBMITTALS

Government approval is required for submittals with a "G" designation; submittals not having a "G" designation are for Contractor Quality Control approval. 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 01330 SUBMITTAL PROCEDURES:

SD-03 Product Data Sealants Primers Bond breakers Backstops Manufacturer's descriptive data including storage requirements, shelf life, curing time, instructions for mixing and application, and primer data (if required). A copy of the Material Safety Data Sheet shall be provided for each solvent, primer or sealant material.

SD-07 Certificates Sealant

Certificates of compliance stating that the materials conform to the specified requirements.

ENVIRONMENTAL CONDITIONS

The ambient temperature shall be within the limits of 40 and 90 degrees F when sealant is applied.

DELIVERY AND STORAGE

Deliver materials to the job site in unopened manufacturers' external shipping containers, with brand names, date of manufacture, color, and material designation clearly marked thereon. Elastomeric sealant containers shall be labeled to identify type, class, grade, and use.

Carefully handle and store materials to prevent inclusion of foreign materials or subjection to sustained temperatures exceeding 90 degrees F or less than 0 degrees F.

PART 2 PRODUCTS

SEALANTS

Provide sealant as indicated below:

Interior Sealant

ASTM C 920, Type S, Grade NS, Class 50, Sanitary Mildew Resistant, USDA approved. Location(s) and color(s) of sealant shall be as follows:

LOCATION COLOR

Small voids between walls or partitions and Gray adjacent lockers, casework, shelving, door frames, built-in or surface-mounted equipment and fixtures, and similar items.

Perimeter of frames at doors, windows, Gray and access panels which adjoin exposed interior concrete and masonry surfaces.

Joints of interior masonry walls and Gray partitions which adjoin columns, pilasters, concrete walls, exterior walls, and overhead structure, unless otherwise detailed.

Joints between edge members for acoustical White tile and adjoining vertical surfaces.

Interior locations, not otherwise indicated Gray or specified, where small voids exist between materials specified to be painted.

Floor Joint Sealant

ASTM C 920, Type S or M, Grade P, Class 25, Use T. Location(s) and color(s) of sealant shall be as follows:

LOCATION COLOR

Seats of metal thresholds for Match adjacent exterior doors. material

Control and expansion joints in floors, Match adjacent slabs, and walkways. material

Acoustical Sealant

Rubber or polymer-based acoustical sealant conforming to ASTM C 919 shall have a flame spread of 25 or less and a smoke developed rating of 50 or less when tested in accordance with ASTM E 84. Acoustical sealant shall have a consistency of 250 to 310 when tested in accordance with ASTM D 217, and shall remain flexible and adhesive after 500 hours of accelerated weathering as specified in ASTM C 734, and shall be non-staining.

PRIMERS

Provide a nonstaining, quick-drying type and consistency recommended by the sealant manufacturer for the particular application.

BOND BREAKERS

Provide the type and consistency recommended by the sealant manufacturer to prevent adhesion of the sealant to backing or to bottom of the joint.

BACKSTOPS

Provide glass fiber roving or neoprene, butyl, polyurethane, or polyethylene foams free from oil or other staining elements as recommended by sealant manufacturer. Backing shall be 25 to 33 percent oversize for closed cell and 40 to 50 percent oversize for open cell material, unless otherwise indicated. Backstop material shall be compatible with sealant. Do not use oakum and other types of absorptive materials as backstops.

Rubber

Cellular rubber sponge backing shall be ASTM D 1056, Type 2, closed cell, Class A, round cross section.

Synthetic Rubber

Synthetic rubber backing shall be ASTM C 509, Option I, Type I preformed rods.

Neoprene

Neoprene backing shall be ASTM D 1056, closed cell expanded neoprene cord Type 2, Class C, Grade 2C2.

CLEANING SOLVENTS

Provide type(s) recommended by the sealant manufacturer.

SEALANTS WITHIN CONTAINMENT

Joint sealants for rubber flooring system to be specified flooring adhesive. Sealant for floor joints at containment coating system and dissimilar materials to be chemical resistant and designed to withstand a high pressure wash (1500 psi) with hot water (200 degrees F). Sealant for joints in the wall and ceiling coating system and dissimilar materials shall also withstand the high pressure wash noted above.

Provide compatible sealant recommended by the coating manufacturer.

PART 3 EXECUTION

SURFACE PREPARATION

Surfaces shall be clean, dry to the touch, and free from dirt frost, moisture, grease, oil, wax, lacquer, paint, or other foreign matter that would tend to destroy or impair adhesion. Oil and grease shall be removed with solvent and surfaces shall be wiped dry with clean cloths. When resealing an existing joint, remove existing calk or sealant prior to applying new sealant. For surface types not listed below, the sealant manufacturer shall be contacted for specific recommendations.

Steel Surfaces

Remove loose mill scale by sandblasting or, if sandblasting is impractical or would damage finish work, scraping and wire brushing. Remove protective coatings by sandblasting or using a residue-free solvent.

Aluminum Surfaces

Remove temporary protective coatings from surfaces that will be in contact with sealant. When masking tape is used as a protective coating, remove tape and any residual adhesive just prior to sealant application. For removing protective coatings and final cleaning, use nonstaining solvents recommended by the manufacturer of the item(s) containing aluminum or bronze surfaces.

Concrete and Masonry Surfaces

Where surfaces have been treated with curing compounds, oil, or other such materials, the materials shall be removed by sandblasting or wire brushing. Laitance, efflorescence and loose mortar shall be removed from the joint cavity.

SEALANT PREPARATION

Do not add liquids, solvents, or powders to the sealant. Mix multicomponent elastomeric sealants in accordance with manufacturer's instructions.

APPLICATION

Joint Width-To-Depth Ratios

Acceptable Ratios:

For metal, glass, or other nonporous surfaces:

1/4 inch (minimum) 1/4 inch 1/4 inch over 1/4 inch 1/2 of Equal to width width

For concrete, masonry, or stone:

1/4 inch (minimum) 1/4 inch 1/4 inch Over 1/4 inch to 1/2 inch 1/4 inch Equal to

Over 1/2 inch to 2 inches

1/2 inch width

5/8 inch Over 2 inches (As recommended by sealant manufacturer)

Unacceptable Ratios: Where joints of acceptable width-to-depth ratios have not been provided, clean out joints to acceptable depths and grind or cut to acceptable widths without damage to the adjoining work. Grinding shall not be required on metal surfaces.

Masking Tape

Masking tape shall be placed on the finish surface on one or both sides of a joint cavity when required to protect adjacent finish surfaces from primer or sealant smears. Masking tape shall be removed within 10 minutes after joint has been filled and tooled.

Backstops

Install backstops dry and free of tears or holes. Tightly pack the back or bottom of joint cavities with backstop material to provide a joint of the depth specified. Install backstops in the following locations:

Where indicated.

Where backstop is not indicated but joint cavities exceed the acceptable maximum depths specified in paragraph entitled, "Joint Width-to-Depth Ratios."

Primer

Immediately prior to application of the sealant, clean out loose particles from joints. Where recommended by sealant manufacturer, apply primer to joints in concrete masonry units, wood, and other porous surfaces in accordance with sealant manufacturer's instructions. Do not apply primer to exposed finish surfaces.

Bond Breaker

Provide bond breakers to the back or bottom of joint cavities, as recommended by the sealant manufacturer for each type of joint and sealant used, to prevent sealant from adhering to these surfaces. Carefully apply the bond breaker to avoid contamination of adjoining surfaces or breaking bond with surfaces other than those covered by the bond breaker.

Sealants

Provide a sealant compatible with the material(s) to which it is applied. Do not use a sealant that has exceeded shelf life or has jelled and can not be discharged in a continuous flow from the gun. Apply the sealant in accordance with the manufacturer's instructions with a gun having a nozzle that fits the joint width. Force sealant into joints to fill the joints solidly without air pockets. Tool sealant after application to ensure adhesion. Sealant shall be uniformly smooth and free of wrinkles. Upon completion of sealant application, roughen partially filled or unfilled joints, apply sealant, and tool smooth as specified. Sealer shall be applied over the sealant when and as specified by the sealant manufacturer.

PROTECTION AND CLEANING

Protection

Protect areas adjacent to joints from sealant smears. Masking tape may be used for this purpose if removed 5 to 10 minutes after the joint is filled.

Final Cleaning

Upon completion of sealant application, remove remaining smears and stains and leave the work in a clean and neat condition.

Masonry and Other Porous Surfaces: Immediately scrape off fresh sealant that has been smeared on masonry and rub clean with a solvent as recommended by the sealant manufacturer. Allow excess sealant to cure for 24 hour then remove by wire brushing or sanding.

Metal and Other Non-Porous Surfaces: Remove excess sealant with a solvent-moistened cloth.

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