CITY OF TACOMA Public Works Department, Facilities Management Division

Transcription

1 CITY OF TACOMA Public Works Department, Facilities Management Division ADDENDUM NO. 2 DATE: July 18, 2018 REVISIONS TO: Request for Bids Specification No. PW N Point Defiance Senior Center, Roof Replacement NOTICE TO ALL BIDDERS: This addendum is issued to clarify, revise, add to or delete from, the original specification documents for the above project. This addendum, as integrated with the original specification documents, shall form the specification documents. The noted revisions shall take precedence over previously issued specification documents and shall become part of this contract. REVISIONS TO THE SUBMITTAL DEADLINE: The submittal deadline was revised to 11 a.m. Pacific Time, Thursday, July 26 th by Addendum #1 REVISIONS TO THE TECHNICAL SPECIFICATIONS: A following spec sections are removed and replaced with the attached: o Remove Section Thermoplastic Membrane Roofing and replace with Section Thermoplastic and PVC Membrane Roofing REVISIONS TO THE PLANS: The following drawings are removed and replaced with the attached: o Replace Sheet A2 Roof Details SUBSTITUTION REQUEST FORMS: Approved substitution request forms are attached. QUESTIONS AND ANSWERS: Question 1: Answer 1: Is there a noise restriction in place for this neighborhood? This project is located within a residential neighborhood. Construction and demolition activity shall NOT be performed between 9 pm and 7am on weekdays or between the hours of 9pm and 9am on weekends and federal holidays. Refer to Tacoma Municipal Code, Chapter Noise Enforcement for Contractor weekday/weekend work hours and noise. Form No. SPEC-220A Revised: 07/30/2015

2 Question 2: Answer 2: What is the rough building occupancy schedule? The regular schedule is Monday through Friday 9am to 3pm. Occasional classes outside those hours and on Saturdays. NOTE: Acknowledge receipt of this addendum by initialing the corresponding space as indicated on the proposal page. Vendors who have already submitted their bid/proposal may contact the Purchasing Division at and request return of their bid/proposal for acknowledgment and re-submittal. Or, a letter acknowledging receipt of this addendum may be submitted in an envelope marked Request for Bids Specification No. PW N Addendum No. 2. The City reserves the right to reject any and all bids, including, in certain circumstances, for failure to appropriately acknowledge this addendum. cc: Mina Zarelli, Facilities Management Form No. SPEC-220A Revised: 07/30/2015

3 SECTION THERMOPLASTIC AND PVC MEMBRANE ROOFING POINT DEFIANCE/RUSTON SENIOR CENTER SECTION THERMOPLASTIC AND PVC MEMBRANE PART 1 GENERAL 1.1 SECTION INCLUDES A. Adhered system with thermoplastic and PVC roofing membrane. B. Insulation, flat and tapered. C. Vapor retarder. D. Roofing cant strips, stack boots, roofing expansion joints, and walkway pads. 1.2 RELATED REQUIREMENTS A. Section Rough Carpentry: Wood nailers, deck sheathing and curbs. B. Section Roof Accessories: Roof mounted units; prefabricated curbs. C. Section Metal Framed Skylights: Skylight frame, integral curb, and counterflashing. 1.3 REFERENCE STANDARDS A. ASTM C1177/C1177M Standard Specification for Glass Mat Gypsum Substrate for Use as Sheathing; B. ASTM C1289 Standard Specification for Faced Rigid Cellular Polyisocyanurate Thermal Insulation Board; C. ASTM D6878/D6878M Standard Specification for Thermoplastic Polyolefin Based Sheet Roofing; D. ASTM E1980 Standard Practice for Calculating Solar Reflectance Index of Horizontal and Low Sloped Opaque Surfaces; E. NRCA ML104 The NRCA Roofing and Waterproofing Manual; Fifth Edition, with interim updates. F. ASTM D4434/D4434M Standard Specification for Poly (Vinyl Chloride) Sheet Roofing. 1.4 ADMINISTRATIVE REQUIREMENTS A. Preinstallation Meeting: Convene one week before starting work of this section. 1. Review preparation and installation procedures and coordinating and scheduling required with related work. 1.5 SUBMITTALS A. See Section Administrative Requirements, for submittal procedures. B. Product Data: Provide data indicating membrane materials, flashing materials, insulation, vapor retarder, surfacing, and fasteners. C. Sustainable Design Documentation: Test report showing solar reflectance index of membrane. D. Specimen Warranty: For approval. E. Shop Drawings: Indicate joint or termination detail conditions, conditions of interface with other materials, and paver layout. F. Manufacturer's Installation Instructions: Indicate membrane seaming precautions and perimeter conditions requiring special attention Page 1 of 6

4 POINT DEFIANCE/RUSTON SENIOR CENTER SECTION THERMOPLASTIC AND PVC MEMBRANE G. Manufacturer's Certificate: Certify that products meet or exceed specified requirements. H. Warranty: 1. Submit manufacturer warranty and ensure that forms have been completed in Owner's name and registered with manufacturer. 2. Submit installer's certification that installation complies with all warranty conditions for the waterproof membrane. 1.6 QUALITY ASSURANCE A. Perform work in accordance with NRCA ML104 and manufacturer's instructions. B. Manufacturer Qualifications: Company specializing in manufacturing the products specified in this section with minimum three years of documented experience. C. Installer Qualifications: Company specializing in performing the work of this section: 1. Approved by membrane manufacturer. 1.7 DELIVERY, STORAGE, AND HANDLING A. Deliver products in manufacturer's original containers, dry, undamaged, with seals and labels intact. B. Store products in weather protected environment, clear of ground and moisture. C. Protect foam insulation from direct exposure to sunlight. 1.8 FIELD CONDITIONS A. Do not apply roofing membrane during unsuitable weather. B. Do not apply roofing membrane to damp or frozen deck surface or when precipitation is expected or occurring. C. Do not expose materials vulnerable to water or sun damage in quantities greater than can be weatherproofed the same day. 1.9 WARRANTY A. See Section Closeout Submittals, for additional warranty requirements. B. System Warranty: Provide manufacturer's system warranty agreeing to repair or replace roofing that leaks or is damaged due to wind or other natural causes. 1. Warranty Term: 20 years. 2. For repair and replacement include costs of both material and labor in warranty. PART 2 PRODUCTS 2.1 MANUFACTURERS A. Thermoplastic Polyolefin (TPO) Membrane Materials: 1. Carlisle Roofing Systems, Inc; Sure Weld TPO, Reinforced Membrane: syntec.com/sle. 2. Firestone Building Products, LLC; UltraPly TPO XR: 3. Flex Membrane International, TPO Plus: 4. Mule Hide, TPO: 5. Substitutions: See Section Product Requirements Page 2 of 6

5 POINT DEFIANCE/RUSTON SENIOR CENTER SECTION THERMOPLASTIC AND PVC MEMBRANE B. Insulation: 1. Atlas Roofing Corporation: 2. Carlisle SynTec: syntec.com/sle. 3. Versico, a division of Carlisle Construction Materials Inc: 4. Duro Guard ISO: last.com 5. Substitutions: See Section Product Requirements. C. Polyvinyl Chloride (PVC) Membrane Materials: 1. Duro Last, last.com 2. Sika Sarnafil, Sikaplan, ROOFING A. Thermoplastic Membrane Roofing: One ply membrane, fully adhered, over vapor retarder and insulation. B. Roofing Assembly Requirements: 1. Solar Reflectance Index (SRI): 78, minimum, calculated in accordance with ASTM E1980. a. Field applied coating may not be used to achieve specified SRI. 2. Insulation Thermal Value (R), minimum: R 38; provide insulation of thickness required. C. Acceptable Insulation Types Tapered Application: Any type that meets requirements and is approved by membrane manufacturer for application. 1. Uniform thickness polyisocyanurate board covered with tapered polyisocyanurate board. 2.3 ROOFING MEMBRANE AND ASSOCIATED MATERIALS A. Membrane: 1. Material: Thermoplastic polyolefin (TPO) complying with ASTM D6878/D6878M or Polyvinyl Chloride (PVC) complying with ASTM D4434/D4434M. 2. Reinforcing: Internal fabric. 3. Thickness: 60 mil (0.060 inch), minimum. 4. Sheet Width: Factory fabricated into largest sheets possible. 5. SRI Rating: 78, minimum, certified by Cool Roof Rating Council. 6. Color: White. B. Seaming Materials: As recommended by membrane manufacturer. C. Vapor Retarder: Material approved by roof manufacturer complying with requirements of fire rating classification; compatible with roofing and insulation materials. 1. Fire retardant adhesive. D. Flexible Flashing Material: Same material as membrane. 2.4 DECK SHEATHING AND COVER BOARDS A. Deck Sheathing: See Section Rough Carpentry B. Cover Board: Glass mat faced gypsum panels, ASTM C1177/C1177M, fire resistant type, 1/4 inch minimum 5/8 inch maximum thick. 1. Manufacturers: a. Georgia Pacific DensDeck, DensDeck Prime, or DensDeck DuraGuard: Page 3 of 6

6 POINT DEFIANCE/RUSTON SENIOR CENTER SECTION THERMOPLASTIC AND PVC MEMBRANE b. Substitutions: See Section Product Requirements. 2.5 INSULATION A. Polyisocyanurate Board Insulation: Rigid cellular foam, complying with ASTM C1289, Type II, Class 1, cellulose felt or glass fiber mat both faces; Grade 2 and with the following characteristics: 1. Compressive Strength: 20 psi. 2.6 ACCESSORIES A. Stack Boots: Prefabricated flexible boot and collar for pipe stacks through membrane; same material as membrane. B. Cant and Edge Strips: Wood fiberboard, compatible with roofing materials; cants formed to 45 degree angle. C. Insulation Joint Tape: Glass fiber reinforced type as recommended by insulation manufacturer, compatible with roofing materials; 6 inches wide; self adhering. D. Insulation Fasteners: Appropriate for purpose intended and approved by roofing manufacturer. E. Membrane Adhesive: As recommended by membrane manufacturer. F. Surface Conditioner for Adhesives: Compatible with membrane and adhesives. G. Thinners and Cleaners: As recommended by adhesive manufacturer, compatible with membrane. H. Insulation Adhesive: As recommended by insulation manufacturer. I. Sealants: As recommended by membrane manufacturer. J. Walkway Pads: Suitable for maintenance traffic, contrasting color or otherwise visually distinctive from roof membrane. 1. Composition: Asphaltic with mineral granule surface or Roofing membrane manufacturer's standard. 2. Surface Color: White or yellow. PART 3 EXECUTION 3.1 INSTALLATION GENERAL A. Perform work in accordance with NRCA ML104 and manufacturer's instructions. B. Do not apply roofing membrane during unsuitable weather. C. Do not apply roofing membrane when ambient temperature is outside the temperature range recommended by manufacturer. D. Do not apply roofing membrane to damp or frozen deck surface or when precipitation is expected or occurring. E. Do not expose materials vulnerable to water or sun damage in quantities greater than can be weatherproofed the same day Page 4 of 6

7 POINT DEFIANCE/RUSTON SENIOR CENTER SECTION THERMOPLASTIC AND PVC MEMBRANE 3.2 EXAMINATION A. Verify that surfaces and site conditions are ready to receive work. B. Verify deck is supported and secure. C. Verify deck is clean and smooth, flat, free of depressions, waves, or projections, properly sloped and suitable for installation of roof system. D. Verify deck surfaces are dry and free of snow or ice. E. Verify that roof openings, curbs, and penetrations through roof are solidly set, and cant strips are in place. 3.3 WOOD DECK PREPARATION A. Verify flatness and tightness of joints of wood decking. Fill knot holes with latex filler. B. Confirm dry deck by moisture meter with 12 percent moisture maximum. 3.4 VAPOR RETARDER AND INSULATION UNDER MEMBRANE A. Apply vapor retarder to deck surface with adhesive in accordance with manufacturer's instructions. 1. Extend vapor retarder under cant strips and blocking to deck edge. 2. Install flexible flashing from vapor retarder to air seal material of wall construction, lap and seal to provide continuity of the air barrier plane. B. Ensure vapor retarder is clean and dry, continuous, and ready for application of insulation. C. Attachment of Insulation: 1. Mechanically fasten first layer of insulation to deck in accordance with roofing manufacturer's instructions. 2. Embed second layer of insulation into full bed of adhesive in accordance with roofing and insulation manufacturers' instructions. D. Lay subsequent layers of insulation with joints staggered minimum 6 inch from joints of preceding layer. E. Place tapered insulation to the required slope pattern in accordance with manufacturer's instructions. F. Lay boards with edges in moderate contact without forcing. Cut insulation to fit neatly to perimeter blocking and around penetrations through roof. G. Tape joints of insulation in accordance with roofing and insulation manufacturers' instructions. H. At roof drains, use factory tapered boards to slope down to roof drains over a distance of 18 inches. I. Do not apply more insulation than can be covered with membrane in same day Page 5 of 6

8 POINT DEFIANCE/RUSTON SENIOR CENTER SECTION THERMOPLASTIC AND PVC MEMBRANE 3.5 MEMBRANE APPLICATION A. Roll out membrane, free from wrinkles or tears. Place sheet into place without stretching. B. Shingle joints on sloped substrate in direction of drainage. C. Overlap edges and ends and seal seams by contact adhesive, minimum 3 inches. Seal permanently waterproof. Apply uniform bead of sealant to joint edge. D. At intersections with vertical surfaces: 1. Extend membrane over cant strips and up a minimum of 4 inches onto vertical surfaces. 2. Fully adhere flexible flashing over membrane and up to nailing strips. E. Around roof penetrations, seal flanges and flashings with flexible flashing. F. Coordinate installation of roof drains and sumps and related flashings. 3.6 CLEANING A. Remove bituminous markings from finished surfaces. B. In areas where finished surfaces are soiled by work of this section, consult manufacturer of surfaces for cleaning advice and conform to their documented instructions. C. Repair or replace defaced or damaged finishes caused by work of this section. 3.7 PROTECTION A. Protect installed roofing and flashings from construction operations. B. Where traffic must continue over finished roof membrane, protect surfaces using durable materials. END OF SECTION Page 6 of 6

9 CONTINUOUS TAPERED TOP PLATE HIGH DOMED, CAPPED, GASKETED FASTENER 4" TYP. PRE-FINISHED GALVANIZED COPING WITH CONTINUOUS CLEAT AUSTINCINA ARCHITECTS, p.s. SLOPE TO ROOF FOR PARAPETS 24" HIGH OR LESS EXTEND BASE FLASHING MEMBRANE OVER PARAPET, TERMINATING FLASHING PLY AT OUTSIDE EDGE OF PARAPET & EXTENDING DOWN OUTSIDE FACE 2" PAST NAILER Pacific Ave. Suite C Tacoma, Washington P: F: E: architects@austincina.com ROOF CONSTRUCTION: TPO FULLY ADHERED 40 MIL. MEMBRANE PROTECTION BOARD R-38 RIGID INSULATION 1/2" PLYWOOD SHEATHING 12" AT HIGH WALL INSTALL TERMINATION BAR FASTENED AT 8" O.C. WITH SEALANT AT ALL WALL TYPES. USE APPROPRIATE FASTENERS FOR SUBSTRATE. USE DRIVE PINS AT CONCRETE WALLS REGISTERED ARCHITECT MICHAEL CINA STATE OF WASHINGTON 40. MIL TPO 4" CANT STRIP 1/2" PLYWOOD SHEATHING, WEATHER RESISTIVE BARRIER, FIBER CEMENT PANEL, PAINT. TERMINATION BAR FASTENED AT 8" O.C. TERMINATES MIN. 4" ABOVE FINISH ROOF LEVEL COUNTERFLASHING - TYPE AS APPLICABLE. SET INTO CONTINUOUS SEALANT TAPE. FASTEN EVERY PANEL RIB. 5/8" COVER BOARD 2 4 SINGLE PLY MEMBRANE BASE FLASHING EXTEND MIN. 4" ONTO FIELD TAPERED POLYISO INSULATION POLYISO INSULATION POLYISO INSULATION TREATED BUILT-UP 2x NAILERS APPROX. 8" SUBSTRATE BOARD VAPOR RETARDER/TEMP ROOF LAP SEALANT, PER ROOF MEMBRANE MANUFACTURE 40 MIL. TPO POLYISO INSULATION FULLY ADHERED (TAPER) POLYISO INSULATION FULLY ADHERED (FLAT) 5/8" DECK SHEATHING 2 4 TOP OF DECKING VAPOR RETARDER WITH FIRE-RETARDANT ADHESIVE (E) PLYWOOD OR CAR DECKING Z-FLASHING 2 TYPICAL BASE FLASHING NOT TO SCALE VERIFY THICKNESS OF EXISTING SIDING 4" (E) PLYWOOD SIDING (E) RIM JOIST (E) ROOF JOIST 2" 2x CURB, P.T. COVERBOARD EQUIPMENT CURB FLASHING A A SINGLE PLY BASE FLASHING 8" MIN. ADHERED ONTO FIELD. EXTEND UP AND OVER CURB MIN. 2" FASTENED AT 3" O.C. LAP SEALANT, PER ROOF MEMBRANE MANUFACTURE 40 MIL. TPO TERMINATION BAR FASTENED AT 8" O.C. WITH SEALANT SINGLE PLY MEMBRANE FULLY ADHERED TO CURB ROOF DETAILS RE-ROOF Pt. Defiance/Ruston Senior Center 4716 N. Baltimore Street, Tacoma, WA POLYISO INSULATION FULLY ADHERED (TAPER) DECK PER STRUCT. POLYISO INSULATION FULLY ADHERED (FLAT) 1 PARAPET, TYPICAL 24 x 36-6" = 1'-0" 12 x 18-3" = 1'-0" 3 VAPOR RETARDER/TEMP ROOF TYPICAL BASE MECHANICAL CURB NOT TO SCALE Job #: Date: Revs: April 5, 2018 A2 PRELIMINARY

10 Tyler CHase Verified by PDFfiller 07/06/2018 Cadence Construction 5821 S Fletcher St Seattle WA tyler@cadenceconstruction TPO Membrane Flex Membranes 60 mil TPO Product is equal to or better than No Changes needed No No Effect Nearly Identical product, nearly identical specs

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