20240801_RFI 40-61_604.pdf

RFI Response – Upgrade of Central Power Plant 604.

31 July 2024

John Duncombe/Ranee Perricone – PM

RFI: Upgrade of Central Power Plant 604.

Questions:

40. Should the temporary roofing mentioned in the tentative schedule be Carlisle coating system in the fluid applied membrane air barrier? Can alternate roofing system be provided in lieu of Carlisle System for temporary roof system?

Response: The fluid applied membrane air barrier is not intended for use as a temporary roof system. The temporary roof system is at the contractor's discretion. The vapor retarder specified in section 07 22 00 – 2.4.1 is an acceptable temporary roof.

41. For the roofing SOW, if a temporary roof is installed, can we delay the installation of the final mod bid roof (based on the tentative schedule provided in the drawings) until the majority (if not all) removal and installation of pipes and curb are complete? It appears in the tentative schedule that a number of the units are getting installed during or even after the roof installment.

Response: The construction schedule is provided for reference only. The contractor is responsible for the construction schedule.

42. In the roofing notes section on drawing A-300, #14 states that all penetrations will be done prior to roof installation. Also, will that include all drains as well?

Response: The intent of this note is to reduce damage to the final roof as much as possible. Some exceptions to the preferred sequence will be necessary.

43. Are all the roofs getting 2 layers of 3" and a 1/4" tapered system on top? It seems as though the specs and drawings do not clarify this.

Response: Tapered insulation areas are indicated on the drawings. The typical multi-ply roof assembly detail 1/A-302 indicates (2) layers of 3” insulation.

44. In section 07 60 00, page 16-18, the chart for the t/z coated copper identifies the thickness of "kilograms per square foot". Should this be ounces per square foot?

Response: Yes, the intent is ounces per square foot.

45. In the sections (Section 07 52 00, Page 18) It has a variety of different application methods. Can we get clarification on if it is cold applied, or torch applied? Nothing is specified for the vapor barrier installation as well.

Response: The intent is to install the products per the manufacturer’s installation guidelines. There are no “hot asphalt applications”. 07 52 00 section 3.3.2.1 can be deleted.

46. The one line drawings E-700 note #1 say to look at the proposed drawing, then the proposed drawing says to look back at the E004 drawing and notes on that drawing. The E004 drawing is a lighting drawing that has no notes, nor does it have any comments about the gear.

Response: Replace “E-004” with “E-005” to see “LOW VOLTAGE POWER

DRAW-OUT CIRCUIT BREAKER REPLACEMENT”

47. Who are the manufacturers of the 480 volt gear SWGR-CCP1200A 480 V Response: See drawing E-005 “LOW VOLTAGE POWER DRAW-OUT CIRCUIT BREAKER REPLACEMENT”. Contact info is noted on the drawing.

48. Drawing E-700 note #2 says back boxes to remain can we use new back boxes and instead of trying to retrofit them with new interiors may take more time to obtain.

Response: Assuming the question is regarding E-701 note 2; Yes, new boxes can be used if there is adequate physical space.

49. Drawing M-603, Water Softener Schedule calls for Model MHC-1500-3 as the basis of design. Basis of design MHC-1500-3 has Connections for Service as 3” and Drain as 2-1/2”. Water Softener schedule calls for Service as 4” and Drain as 2”. Please confirm the size of service and Drain connection sizes.

Response: The existing piping serving the water softeners is 4”. All piping to and from the water softeners shall be 4” as shown in the section on M-301. The piping connections at each softener may be 3” as long as the requested capacity of the softener can be provided and a reducer fitting used at the point of connection.

50. Please confirm if the Basis of Design for Water Softener is MARLO/ATI-NY

MHC-1500-3.

Response: Confirmed, however, several modifications from the standard model, including modifications to meet height restrictions, space constraints and other items noted are required.

51. Drawing M-603 Water Softener Schedule note 2 call for WS-1/2 in lead-lag redundant configuration. Please confirm if this note is saying that the WS-1 and WS-2 should work in lead-lag redundant configuration as required to meet flow requirements.

Response: Duplicate question, refer to previously issued response.

52. Drawing M-603 Water Softener Schedule note 4 calls for an access manway.

Typically, manway is 11”x15”. Specification section 22 31 00, Para 2.2.2 calls for

4”x6” or larger for the lower side shell. Please confirm if 11”x15” access manway is required as per Note 4 or 4”x6” hand hole as per the specifications.

53. Specifications section 22 31 00 para 2.2.2 refer to false bottom in the tank. Is it acceptable if the internals go all the way down into the head?

54. Please confirm if PVC Sch 30 strainer heads are acceptable as per Specifications section 22 31 00 Para 2.2.3.1.

55. Specification section 22 31 00 Para 2.2.4 calls for various grades of gravel for the under bedding. Is one grade of #20 Flint product acceptable?

56. Specification Section 22 31 00 Para 2.31 Calls for Steel or fiber glass filament-wound reinforced plastic construction for tanks. Are HDPE tanks acceptable?

57. Specification Section 22 31 00 Para 2.7.1 Calls for a water meter for each unit.

For a twin alternating system, there is generally one meter in the common outlet.

The meter connects to one controller. The flow readout and totalization can be read in the diagnostics section of each controller. Please confirm if this is acceptable.

Response: A single flow meter is acceptable as long as individual run times/totalization of each softener are available to the operator.

58. Drawing M-603 Water Softener Schedule note 3 calls for Max. overall softener height as 96”H. The side shell of the tank is 60”. Each 54” diameter ASME tank head is 15.5”. This makes the overall height for just the tank and heads to 91”. If 3” clearance is provided for the tank, and 1” for couplings sticking out, total height will become 95”. Our supplier thinks we do not have enough space to put a relief valve as mentioned in note 4 of Drawing M-603 Water Softener Schedule.

59. Drawing C-200 has no scale indicated. Please confirm the scale for drawing C- 200.

Response: The scale of the main portion of Drawing C-200 is 1” = 10’-0”.

60. Contract Drawing A-004, Phasing Plan General Note 35 calls for providing internet for the owner use. Please confirm if this is just to cover the temporary office space being provided as part of this contract.

Response: The intent is to provide continuous internet service for owner use at the spaces functioning as break rooms, offices, and control booths. The locations of these spaces will change as the renovation proceeds.

61. Clarification needed. Question 1 on Addendum 2 Spec 1.20

Please take note that the minimum bearing surface for curb is to be 3/8” thick and 8” wide. The steel girt must have a flat landing area for the skylight of at least 8”. More is fine, less than 8” is unacceptable.

Recommendation:

Provide a steel beam with a minimum bearing surface of 8” in width and 3/8 minimum in depth for the skylight system to attach to.

Or cap the beam with a plate with minimum dimensions of 3/8” thick x 8” wide steel.

Response: Assuming the question is regarding the skylight curb; the previous response indicated that “Per the basis of design manufacturer’s detail, the skylight will anchor directly to the 12x26 steel indicated on the structural drawings.” The top flange of the steel beam is larger than the minimum dimensions required by the manufacturer.