Air sampling protocol document, 130 Cedar Street, Jan 2005

NYC 9/11 Public Portal Document

130 Cedar Street July 15, 2004 Selective Demolition and Façade Restoration Koenen Associates

b. Remove laitance by grinding or mechanical abrading. c. Remove loose particles present or resulting from grinding, abrading , or blast cleaning by blowing out joints with compressed air, oil and water •

free, or vacuuming joints prior to application of primer or sealant. 3. Clean non-porous surfaces such as metal and glass chemically. Remove protective coatings on metallic surfaces by solvent that leaves no residue and is compatible with sealant. Use solvent with clean, lint free paper towels, and wipe dry with clean, dry lint free paper towels. Do not allow solvent to air dry without wiping. Clean joint areas protected with masking tape or strippable films as above after removal of tape film. 4. Joint Size and Sealant Size: Joints to receive sealant shall be at least 1/4" wide. In joints 1/4" to 3/8" wide, sealant shall be 114" deep. In joints wider than 3/8" and up to 1" wide, sealant depth shall be one half the joint width. For joints wider than 1" sealant depth shall be as recommended by the sealant manufacturer. Depth of joint Is defined as distance from outside face of joint to closest point of the filler. 5. Primer Thoroughly clean joints and apply primer to all surfaces that will receive sealant. Apply primer on clean, dry surfaces, and prior to Installation of joint backing. Completely wet both Inner faces of the joint with primer. Mask adjacent surfaces of joint with non-staining masking tape prior to priming. 6. Joint Backing: In joints where depth of joint exceeds required depth of sealant, install Joint backing (after primer Is dry) In joints to provide backing and proper joint shape for sealant. Proper shape for sealant Is a very slight "hourglass" shape, with back and front face having slight concave curvature. Use special blunt T- shaped tool or roller to Install joint backing to the proper and uniform depth required for the sealant. Joint backing shall be Installed with approximately twenty-five (25) percent compression. Do not stretch, twist, braid, puncture, or tear joint backing. Butt joint backing at intersections. 7. Bond Breaker. Install bond breaker smoothly over joint backing so that sealant .. adheres only to the sides of the joint and not backing. 8. Sealant Application: Apply sealant In accordance with the manufacturer's application manual and manufacturer's instructions, using hand guns or pressure equipment, on clean, dry, properly prepared substrates, completely filling joints to eliminate air pockets and voids. Mask adjacent surfaces of joint with non-staining masking tape. Force sealant into joint in front of the tip of the "caulking gun" (not pulled after It) and force sealant against sides to make uniform contact with sides of joint and to prevent entrapped air or pulling of sealant off of sides. Fill sealant space solid with sealant. 9. Tooling: Tool exposed joints to form smooth and uniform beds, with slightly concave surface. Finished joints shall be straight, uniform, smooth and neatly finished. Removed masking tape Immediately after tooling of sealant and before sealant face starts to "skin" over. Neatly remove any excess sealant from adjacent surfaces of joint, leaving the work in a neat, clean condition. 10. Replace any sealant which is damaged during construction process. 11. No prepared joint or crack shall be left unsealed at the completion of each day's work.

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Joint Sealers 07900-3

NYC-WTC 000125202