steam damage.docx

PNQS 25-0034 Repair Steam Damage, Maxwell Building 1154 Maxwell AFB, AL RFI Questions /Response

1. Will any electrical components damaged by water be a part of the Contract or will it be treated as a Change Order? Change Order

2. For clarity, the SOW says remove damaged sheetrock and replace it with fire retardant foam sprayed on the underside of roof deck in steam room. Will new sheetrock need to be replaced? If so, what sheetrock size and type? Do not replace the sheetrock ceilings in the mechanical room.

3. Will the Contractor be responsible for any leaks not associated with pipe burst? Water damage was caused by separated boiler flue gas exhaust pipe. Repair of and modification of boiler flue gas piping is part of the scope of work. See specification 01000, paragraph 1.01, Summary of Work.

4. There will be duct board removed and replaced. If any duct has damage, will the unforeseen be treated as a Change Order? Remove and replace all duct insulation board within the confines of the mechanical room. All fiberglass duct board shall be per the following:

Insulation and vapor retarder/vapor barrier shall be provided for the following cold air ducts and associated equipment.

a. Supply ducts.

b. Return ducts.

c. Duct-mounted coil casings.

d. Coil headers and return bends.

e. Fresh air intake ducts.

Insulation board for rectangular ducts shall be rigid type where exposed, minimum thickness 2” thick on supply ducts and 1-1/2” thick on return and outside air ducts. Density of insulation board shall be 3 PCF. Insulation for both concealed or exposed round/oval ducts shall be flexible type, minimum density 3/4 pcf or a semi rigid board, minimum density 3 pcf, formed or fabricated to a tight fit, edges beveled, and joints tightly butted and staggered. Insulation for all exposed ducts shall be provided with either a white, paint-able, factory-applied Type I jacket or a field applied vapor retarder/vapor barrier jacket coating finish as specified, the total field applied dry film thickness shall be approximately 1/16 inch. Insulation on all concealed ducts shall be provided with a factory-applied Type I or II vapor retarder/vapor barrier jacket. Duct insulation shall be continuous through sleeves and prepared openings except firewall penetrations. Duct insulation terminating at fire dampers, shall be continuous over the damper collar and retaining angle of fire dampers, which are exposed to unconditioned air, and which may be prone to condensate formation. Duct insulation and vapor retarder/vapor barrier shall cover the collar, neck, and any un-insulated surfaces of diffusers, registers and grills. Vapor retarder/vapor barrier materials shall be applied to form a complete unbroken vapor seal over the insulation.

Installation on Exposed Duct Work

a. For rectangular ducts, rigid insulation shall be secured to the duct by mechanical fasteners on all four sides of the duct, spaced not more than 12 inches apart and not more than 3 inches from the edges of the insulation joints. A minimum of two rows of fasteners shall be provided for each side of duct 12 inches and larger. One row shall be provided for each side of duct less than 12 inches. Mechanical fasteners shall be as corrosion resistant as G60 coated galvanized steel and shall indefinitely sustain a 50 lb tensile dead load test perpendicular to the duct wall.

b. Form duct insulation with minimum jacket seams. Fasten each piece of rigid insulation to the duct using mechanical fasteners. When the height of projections is less than the insulation thickness, insulation shall be brought up to standing seams, reinforcing, and other vertical projections and shall not be carried over. Vapor retarder/barrier jacket shall be continuous across seams, reinforcing, and projections. When the height of projections is greater than the insulation thickness, insulation and jacket shall be carried over. Apply insulation with joints tightly butted. Neatly bevel insulation around name plates and access plates and doors.

c. Impale insulation on the fasteners; self-locking washers shall be installed, and the pin trimmed and bent over.

d. Seal joints in the insulation jacket with a 4-inch-wide strip of tape. Seal taped seams with a brush coat of vapor retarder coating.

e. Breaks and ribs or standing seam penetrations in the jacket material shall be covered with a patch of the same material as the jacket. Patches shall extend not less than 2 inches beyond the break or penetration and shall be secured with tape and stapled. Staples and joints shall be sealed with a brush coat of vapor retarder coating.

f. At jacket penetrations such as hangers, thermometers, and damper operating rods, the voids in the insulation shall be filled and the penetrations sealed with a flashing sealant.

g. Insulation terminations and pin punctures shall be sealed and flashed with a reinforced vapor retarder coating finish. The coating shall overlap the adjoining insulation and un-insulated surface 2 inches. Pin puncture coatings shall extend 2 inches from the puncture in all directions.

h. Oval and round ducts, flexible type, shall be insulated with factory Type I jacket insulation with minimum density of 3/4 pcf, attached as in accordance with MICA standards.

5. Will the Contractor be responsible for the existing damaged ceiling grid? Yes

6. The existing exhaust fan in the mechanical room is not operational. Replacement of mechanical room ventilation fan and piping insulation is not part of the project scope.

7. How should this be addressed? Repair existing fan or replace fan? Will the pipe insulation need to be replaced in the mechanical room? Replacement of mechanical room ventilation fan and piping insulation is not part of the project scope.

8. If this needs to be replaced, an additional site visit will be required. Replacement of mechanical room ventilation fan and piping insulation is not part of the project scope.