Q&A DTFAAC-17-R-02323.pdf

FAA-MMAC MISCELLANEOUS MECHANICAL CONSTRUCTION SERVICES

SIR/RFO: DTFAAC-17-R-02323

BIDDING QUESTIONS:

Who handles boilers? The heating and chilled water systems are operated and maintained by the FAA’s AMP-300 department. Any outages to the systems will be coordinated through the FAA project manager.

What kind of pipe? The heating and cooling main piping in the building is schedule 40 black steel. Since the piping to this AHU was not replaced during the 2009 renovation, it is possible that the run-out piping is copper. Either schedule 40 black steel or hard-drawn copper tubing “Type L”, is allowed in the specifications. All connections to a dissimilar metal shall be done using a dielectric union.

How old is the roof?’ The roof was installed in 2009. It is RFS-Built-up construction.

Is there a warranty on the roof? Yes. The roof warranty is held by John Mansfield.

Is this a repair or a re-roof? Neither, it’s a modification. The roof will need to be removed and replaced within 4 feet of the new RTU roof curb. Refer to the specifications and roofing details on M3. Walk pads will be installed on both the existing & modified areas as shown.

Sprinkler system into the new deck? There is no fire sprinkler system work currently in the SOW. Once construction is underway, if it is determined that some of the sprinkler heads need to be relocated to accommodate the duct layout, it will be added to the contract by modification.

Does the floor stay? The contractor shall repair damaged mezzanine floor boards per Sheet M1, detail A.

Do we need to cover the painted floor? The contractor will need to supply Masonite sheets to cover floor space where equipment will be operating.

How thick is the slab? 6”

What are the weight limits on the roof? There is currently a structural assessment of the roof structure underway. If there are structural modifications required to install the RTU, they will be addressed through a separate contract. Time delays are not expected.

Can the RTU be skated into position vs crane lifted? No. Lifting the RTU into place is required.

How will the unit be supported on the roof? The contractor shall provide a roof curb. There is currently a structural assessment of the roof structure underway. If there are structural modifications required to install the RTU, they will be addressed through a separate contract.

Are the chilled and hot water lines copper or carbon? The heating and cooling main piping in the building is schedule 40 black steel. Since the piping to this AHU was not replaced during the 2009 renovation, it is possible that the run-out piping is copper. Either schedule 40 black steel or hard-drawn copper tubing “Type L”, is allowed in the specifications.

All connections to a dissimilar metal shall be done using a dielectric union.

Can pro-press fittings be used on copper lines? Pro-press fittings are currently not accepted per the specification.

What are the rules for equipment on painted floors? White tires shall be used on equipment. The contractor will need to supply Masonite sheets to cover floor space where equipment will be operating.

FAA Clarifications:

There is an overhead door at the south end of the high bay area that may be used to move equipment in and out of the space. Clearance is limited due to the sled and the lighting system.

There is a large sliding door within the high-bay that separates the impact sled space from the area on the north side of the equipment mezzanine. The sliding door and beam can be removed to allow equipment access to that area. The opening is approximately 23 feet wide.

The lightning protection system on the roof will be modified per the plans. The UL Certification of the lightning protection system will not be recertified as part of this project.

The FAA has identified asbestos containing materials on the existing air-handling unit. Abatement of the asbestos containing materials is not included in the scope of this project. The FAA will coordinate the abatement schedule with the construction schedule for least disruption to the space tenants and the AHU construction project.

The height of the mezzanine floor is approximately 26 feet.