Fax cover sheet from J.C. Broderick & Associates, Oct 2001

NYC 9/11 Public Portal Document

vi. Filler materials used to repair damaged and missing areas of asbestos-containing material shall contain no asbestos, shall adhere well to the substrate and shall provide an adequate base for the encapsulating agent.

vii. Encapsulated asbestos-containing materials shall be identified by signs, labels, color coding or some other mechanism to warn persons who may be required to disturb the material that asbestos is present.

viii. Where encapsulants are sprayed on asbestos-containing materials:

1. Low pressure airless spray shall be used. The airless spray gun shall have an appropriately sized tip which shall be tested by briefly spraying the encapsulant onto a surface from approximately 12 inches away. An appropriately sized tip will spray the encapsulant in a fan approximately eight inches wide; it will also distribute the encapsulant uniformly within the fan, giving even coverage.

2. A suitable quantity of HEPA filtration units shall be used during the• encapsulation process which shall have sufficient capacity to cause one complete air exchange every 30 minutes.

3. At least three coats of the encapsulant shall be applied to the surface of the asbestos-containing material. Each coat shall be applied in a two-step procedure. The first step is to apply a light mist coat to moisten and seal any loose fibers and keep them from breaking away from the surface. This mist coat should be applied in three or four quick passes with the gun held 18 to 24 inches from the surface. After an area of 16 to 20 square feet has been give the mist coat, a heavier coating is applied, using 8 to 10 passes with the gun held 10 to 12 inches from the material. The gun should be kept in constant motion to create a smooth and even coat. This two-step application shall be considered one coat of encapsulant. Each subsequent coat shall be applied at a 90 degree angle to the direction of the preceding coat application, to ensure complete coverage of the asbestos-containing material. When questions rise regarding drying time, curing time, dilution, or use under different weather conditions, the manufacturer's recommendations and instructions shall be consulted.

4. All other preparation, decontamination, and work requirements and procedures used in encapsulation projects shall be the same a those used in removal projects.

5. Sealants used in the encapsulation shall not alter the existing fire rating and shall be flame resistant and meet the flame spread and smoke generation requirements of Federal, State and Local guidelines.

NYC-WTC 000104872