NYC-WTC_000233286

NYC 9/11 Public Portal Document

(C) Removal of Mounted Objects. After critical barriers and isolation barriers are in place, mounted objects shall be removed and HEPA-vacuumed or wet wiped or both. Localized HEPA-filtered vacuum equipment shall be used during mounted object removal to reduce potential asbestos dispersal.

(d) Elevator Shutdown or Isolation. Elevators running through the regulated abatement work area shall be shut down except as noted in this Subdivision:

(1) Isolation Detail. In projects where the elevator cannot be shut down, the hoistway door frames shall be enclosed with nominal 2” x 4” framing, 16 inch on center, covered with 3/8-inch thickness plywood or OSB sheathing, and caulked or duct taped airtight at all seams. The enclosures shall be covered with two (2) seamless layers of at least six (6) mil plastic sheeting duct taped and sealed airtight. A final larger layer of at least six (6) mil plastic sheeting shall be duct taped and sealed airtight, but with slack, forming a larger perimeter diaphragm to sense air movement caused by elevator operation. (2) Elevator Shaft Ports. Elevator shaft ports for pressure equalization when within the regulated abatement work area, shall be vented to the outside or non-work areas using oversized solid-walled ducts or chambers constructed with 3/8-inch thickness plywood or OSB sheathing over nominal 2” x 4” framing, 16 inch on center. The joints shall be caulked and the ducts or chambers shall be sealed with two (2) layers of at least six (6) mil fire-retardant plastic sheeting and duct tape. The first layer of plastic sheeting shall be attached to the ducts or chambers using spray adhesive. This system shall be subjected to and pass a negative pressure test daily. (e) Floor, Wall & Ceiling Plasticizing and Sealing. All floor, wall and ceiling surfaces, except where abatement of ACM, PACM or asbestos material shall be performed on those specific surfaces, shall be covered with two (2) layers of, at a minimum, six (6) mil fire-retardant plastic sheeting. The floor shall be plasticized first, and its plastic sheeting shall extend up the walls a distance of at least twelve (12) inches on all sides. The walls shall then be plasticized by applying plastic sheeting from the ceiling to the floor, overlapping the floor sheeting by at least twelve (12) inches. Next, the ceiling shall be plasticized overlapping the walls by at least twelve (12) inches, to form a secure airtight seam. This process shall be repeated for the second layer of plastic sheeting for the floor, walls and ceiling. All seams within a layer shall be separated by a distance of at least six (6) feet and sealed airtight with duct tape. All seams between layers shall be staggered at least two (2) feet. (f) Barrier/Plasticizing Exemptions. (1) Negative Pressure Tent Regulated Abatement Work Area Enclosure. An alternate isolation method may be used where preparation of the entire room/space is either unfeasible or not necessary to adequately access all impacted ACM, PACM or asbestos material.

12 NYCRR56 Subpart?, Page 67

CITY_21MC100_003235087

NYC-WTC_000233353