16320.79 SPD O'Brien Upper Envelope_Pre-Bid-Addendum_#2_20200424.pdf

ADDENDUM NO. 2

Project: Upper Envelope Project Leo O’Brien Federal Office Bldg.

10 Clinton Street Albany, NY 1

Date of Issue: April 24, 2020

TO ALL BIDDERS: The following additions, deletions, and/or changes or clarifications to the drawings, specifications, and bidding documents for this project, shall become and are hereby made part of the Contract Documents. They change the original documents only in the manner and to the extent stated. Each bidder shall acknowledge receipt of this ADDENDUM in the appropriate location on the bid proposal form.

This ADDENDUM consists of two (2) pages, including this page. All requirements of the original Specifications and Drawings and previous Addenda, if applicable, shall remain in force except as noted by this ADDENDUM.

THE PURPOSE OF THIS ADDENDUM IS TO CHANGE THE FOLLOWING ITEMS:

1.0 SPECIFICATIONS

1.1 SECTION 075423 – THERMOPLASTIC-POLYOLEFIN (TPO) ROOFING

1.1.1 ADD new para. 3.2.1 as follow:

“3.2.1 - VAPOR RETARDER APPLICATION

A. Clean, prepare, and treat substrates according to manufacturer's written instructions. Provide clean, dust-free, and dry substrates for vapor retarder application. Install sheet strips and center over treated construction and contraction joints and cracks exceeding a width of 1/16 inch (1.6 mm).

B. Bridge and cover isolation joints, expansion joints and discontinuous deck-to-wall and deck-to-deck joints with overlapping sheet strips. Invert and loosely lay first sheet strip over center of joint. Firmly adhere second sheet strip to first and overlap to substrate.

C. Corners: Prepare, prime, and treat inside and outside corners according to ASTM D 6135.

D. Prepare, treat, and seal vertical and horizontal surfaces at terminations and penetrations through vapor retarder and at drains and protrusions according to ASTM D 6135.

3.3 - FIELD QUALITY CONTROL

A. Engage a full-time site representative qualified by vapor retarder membrane manufacturer to inspect substrate conditions; surface preparation; membrane application, flashings, protection, and drainage components; and to furnish daily reports to Contracting Officer’s Representative or designated representative.

3.4 - PROTECTION AND CLEANING

A. Do not permit foot or vehicular traffic on unprotected membrane.

B. Protect vapor retarder from damage and wear during remainder of construction period.

C. Protect installed extruded polystyrene insulation from damage due to ultraviolet (UV) light, harmful weather exposures, physical abuse, and other causes. Provide temporary coverings where insulation will be subject to abuse and cannot be concealed and protected by permanent roof immediately after installation.

D. Clean spillage and soiling from adjacent construction using cleaning agents and procedures recommended by manufacturer of affected construction.”

1.2 SECTION 076200 - SHEET METAL FLASHING AND TRIM

1.2.1 Paragraph 2.2 ADD new subparagraph “B” as follows:

“B. Contractor shall provide minimum .050" thick aluminum for scuppers, gutters and downspouts. Contractor shall provide minimum .063" thick aluminum for fascia, flashing and counterflashing. Color Anodic Finish, Coil Coated: AAMA 611, AA-M12, C22A42/A44, Class I, 0.018 mm or thicker.”

1.3 SECTION 078413 - PENETRATION FIRESTOPPING

1.3.1 Paragraph 1.1A.1 – REPLACE a, b and c as follows:

“a. Penetrations from the Mechanical Rooms or Floors below roof decks. No new partitions are being installed.”

1.4 SECTION 099113 – PAINTING

1.4.1 Paragraph 3.3 ADD new subsection “C” as follows:

“C. Contractor shall follow SSPC-SP2 Hand Tool Cleaning standards. For the removal of loose mill scale, loose rust, loose paint, and other loose detrimental foreign matter from surfaces with the use of non-powered hand tools.”

1.5 SECTION 075900 – ELECTRONIC LEAK DETECTION (ELD) - LOW VOLTAGE VECTOR

MAPPINGTHERMOPLASTIC-POLYOLEFIN (TPO) ROOFING:

1.5.1 Paragraph 1.1A.2 – DELETE this sentence.

NOTE: ELD required is a one-time occurrence testing method, not a permanently installed system, following roof installation completion.

1.6 SECTION 264113 – LIGHTNING PROTECTION FOR STRUCTURES

1.6.1 Paragraph 1.5B – DELETE this sentence in its entirety. REPLACE with the following:

“B. Contractor shall provide inspection and testing of the grounding and downleads and confirm that they meet the requirements to obtain a UL Master Label for the complete lightning protection system. The contractor shall provide documentation of this testing and inspection.”

2.0 DRAWINGS

2.1 Sheet AD102: Demo Plan-Keyed Notes

2.1.1 CHANGE to read as: "DEMO PLAN- KEYED NOTES- SHEET AD102 - A”.

2.2 Sheet AE101: FLOOR PLAN - KEYED NOTES- AE101 - Keyed Note 1

2.2.1 CHANGE “Peel and Stick Vapor Barrier” to “Torch Down Vapor Barrier".

2.3 Sheet AE5-1: Detail 8 & 8/Alt.

2.3.1 CHANGE note “PROVIDE DRAIN BODY” to "EXISTING DRAIN BODY".

END OF ADDENDUM NO. 2