210040_ATT2_Design_Narrative_Final.pdf

Design Narrative_v1_06/17/20

Design Narrative Repair Roof Sections 7, 8, 9, 10, 19 & 20, B3102

Project Number: WWYK210040 Work Order: 21777

Tinker Air Force Base, Oklahoma

May 29, 2024

Prepared By:

THDR

7535 5th Street, Building 400

Tinker AFB, OK 73145

WWYK210040 – Repair Roof Sections 7, 8, 9, 10, 19 and 20, B3102

May 29, 2024 | i

CONTENTS

Acronyms and Abbreviations ......................................................................................................................... iii

1. Overview

2. Applicable Codes and Standards

2.1 General

2.2 Architectural

2.3 Structural

2.4 Mechanical / Plumbing

2.5 Electrical

3. Architectural Design Narrative

3.1 General Design Parameters and Assumptions

3.1.1 Master Plan/Future Expansion

3.1.2 Visual Features

3.1.3 Accessibility

3.1.4 Energy Conservation

3.1.5 Life Safety

3.1.6 Security

3.2 Architectural Demolition

3.3 Architectural Construction

4. Structural Design Narrative

4.1 General Design Parameters and Assumptions

4.1.1 Structural Steel

4.1.2 Steel Design

4.1.3 Structural Loads

4.2 Structural Demolition

4.2.1 Thru Wall Scupper

4.3 Structural Construction

4.3.1 Thru Wall Scupper

5. Mechanical Design Narrative

6. Electrical Design Narrative

6.1 Electrical Demolition

6.2 Electrical Construction

7. Fire Protection / Life Safety Design Narrative – N/A

7.1.1 Fire Extinguishers

7.2 Safeguards During Construction

7.2.1 Hot Work

7.2.2 Fire Protection Impairment Supervision

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8. Intrusion Detection System (IDS) Design Narrative – N/A

9. Access Control System (ACS) Design Narrative – N/A

10. Communications Design Narrative

11. Phasing Plan – N/A

APPENDICES

Appendix A: Architectural Calculations and Cut sheets

Appendix B: Structural Calculations and Cut sheets

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ACRONYMS AND ABBREVIATIONS

A Ampere(s) AABC Associated Air Balance Council

ACCA Air Conditioning Contractors Association

ACI American Concrete Institute

ACS Access Control System

ACT Acoustic Ceiling Tile

AFB Air Force Base

AFF Above Finished Floor

AFI Air Force Instruction

AHJ Authorities Having Jurisdiction

AHU Air Handling Unit

AISC American Institute of Steel Construction

ANSI American National Standards Institute

ASCE American Society of Civil Engineers

ASHRAE American Society of Heating, Refrigeration and Air‐Conditioning Engineers

ASTM American Society for Testing and Materials

BTHU British thermal unit

BUR Built‐Up Roof

CAC Common Access Card

CBT Computer Based Training

CCTV Closed Circuit Television

CIPS Cyberspace Infrastructure Planning System

CMU Concrete Masonry Unit

COMM Communications

DB Dry Bulb

DoD Department of Defense

DX Direct Expansion

E East

EBI Enterprise Building Integrator

EMI Electromagnetic Interference

EMT Electrical Metallic Tubing

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FCI Fire Control Instruments FCU Fan Coil Unit

FF‐L Federal Specification

FPS Feet Per Second

FT Feet

GSA General Services Administration

HR Hour(s)

HSS Hollow Structural Section

HVAC Heating, Ventilation and Air Conditioning

IAW In Accordance With

IBC International Building Code

IC Intelligence Community

ICD Intelligence Community Directive

ICS Intelligence Community Standard

IDS Intrusion Detection System

IEBC International Existing Building Code

IECC International Energy Conservation Code

IMC International Mechanical Code

IN Inches

IPC International Plumbing Code

IT Information Technology kVA Kilovolt‐Ampere

LAN Local Area Network

LED Light Emitting Diode

MOD Motorized Damper

N North

NEBB National Environmental Balancing Bureau

NFPA National Fire Protection Association

NIPR Non‐Secure Internet Protocol Router

PSF Pounds per Square Foot

RF Radio Frequency

RFI Radio‐Frequency Interference

SIPR Secure Internet Protocol Router

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SMACNA Sheet Metal and Air Conditioning Contractors' National Association S South

STC Sound Transmission Class

TAFB Tinker Air Force Base

UFC Unified Facilities Criteria

UPS Uninterruptible Power Supply

V Volts

VAV Variable Air Volume

W West

WB Wet Bulb

WG Water Gauge

§ Subsection °F Fahrenheit

WWYK210099 – Repair Roof Sections 7, 8, 9, 10, 19 and 20, B3102

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1. Overview

Demolish existing roofing system and all associated accessories and repair and replace with new membrane roof and all associated accessories. Demolish and repair and replace all penetrations and remove equipment that are no longer in use. Repair all roofing issues to create a watertight roof. Various items will need to be removed and replaced after new roofing system installation has occurred. Roofs are to have code compliant roofing slopes and secondary drainage added to comply with UFC criteria.

2. Applicable Codes and Standards

2.1 General

IBC International Building Code (as amended by UFC 1‐200‐01) IEBC International Existing Building Code NFPA 101 Life Safety Code TAFB Facility Standard UFC 1‐200‐01 General Building Requirements UFC 4‐010‐01 DoD Minimum Antiterrorism Standards for Buildings

2.2 Architectural

UFC 3‐101‐01 Architecture UFC 3‐110‐03 Roofing UFC 3‐190‐06 Protective Coatings and Paints

2.3 Structural

ACI 318‐14 Building Code Requirements for Structural Concrete and

Commentary AISC 360‐16 Steel Construction Manual, 15th Ed.

ASCE 7‐16 Minimum Design Loads for Building and other Structures AISI S100‐16 North American Specification for the Design of Cold‐formed

Steel Structural Members UFC 3‐301‐01 Structural Engineering

2.4 Mechanical / Plumbing

ASHRAE 90.1 Energy Standard for Buildings Except Low‐Rise Residential

Buildings IECC International Energy Conservation Code IMC International Mechanical Code (as amended by UFC 3‐410‐01) IPC International Plumbing Code (as amended by UFC 3‐420‐01) TAFB Mechanical Standard UFC 3‐400‐02 Design: Engineering Weather Data UFC 3‐401‐01 Mechanical Engineering UFC 3‐410‐01 Heating, Ventilating, and Air Conditioning Systems UFC 3‐420‐01 Plumbing Systems

2.5 Electrical

NFPA 70 National Electrical Code NFPA 780 Standard for Installation of Lightning Protection Systems

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TAFB Electrical Standard WWYK210099 – Repair Roof Sections 11, 12, 13, 14, 15, 21 and 22, B3102

UFC 3‐501‐01 Electrical Engineering UFC 3‐530‐01 Interior and Exterior Lighting Systems and Controls UFC 3‐575‐01 Lightning and Static Electricity Protection Systems AFMAN 32‐1065 Grounding and Electrical System.

2.6 Fire Protection

NFPA 1 Fire Code NFPA 10 Standard for Portable Fire Extinguishers NFPA 51B Standard for Fire Prevention during Welding, Cutting, and Other

Hot Work NFPA 70 National Electric Code NFPA 72 National Fire Alarm Code NFPA 90A Standard for the Installation of Air‐Conditioning and Ventilation

Systems NFPA 241 Standard for Safeguarding Construction, Alteration, and

Demolition Operations TAFB Mechanical Standard TAFB Electrical Standard UFC 3‐600‐01 Fire Protection Engineering For Facilities UFC 3‐601‐02 Operation and Maintenance: Inspection, Testing and

Maintenance of Fire Protection Systems

3. Architectural Design Narrative

Removal and replacement of the existing modified built‐up roofing system over building B3102.

All abandoned penetrations are to have decking infilled and roofed over and all penetrations to remain are to have new flashing.

3.1 General Design Parameters and Assumptions

Conform new walk pad system as per UFC 3‐110‐03 Roofing requirements.

3.1.1 Visual Features

No visual changes from ground level other than new roof scuppers as secondary overflow drains.

3.1.2 Accessibility

The Existing roof has multiple access points. All roofing access ladders were visually inspected and appeared to be in good condition and are to remain.

3.1.3 Energy Conservation

New roof system will meet cool roof standards per UFC 3‐110‐03 Roofing. Insulation thickness is to be increased as required to meet current roofing insulation standards per UFC 3‐110‐03 Roofing.

3.1.4 Security

See communications section.

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3.2 Architectural Demolition

Remove existing built‐up gravel roofing system down to the structural deck. All flashings, counter flashing, parapet coping caps, downspouts, conductors and gutters are to be removed for replacement.

Roofs with only single primary drains are to have secondary drains installed as a part of reroofing efforts. Tinker AFB standard preference is scupper overflow drains that are daylighted.

An EM survey indicates there are asbestos containing materials (ACM) and lead based paint (LBP) concerns in the B3102 roofing area. Black and gray roofing material; black shingles, gray shingles, black roof material within the tar under the gravel and flashings, throughout the roof working area are confirmed and presumed to be asbestos containing. Also, many roof and drain vents throughout the area contained lead based coverings. The Contractor is to test as needed to determine if ACM and LBP exist. Testing is to occur during design phase services. If testing indicates hazardous materials exist, contractor is to follow Tinker AFB standards for abatement prior to demolition of roofing system.

For roofs that do not meet minimum roof pitch per UFC 3‐110‐03 Roofing, modifications will be required during design phase to ensure minimum roof pitches per code requirement are met.

In meeting minimum roof pitch requirements and providing overflow scupper drainage requirements, existing parapets may need to be modified and/or raised to account for increased roof thickness and / or to account for space needed between the new roofing and the coping cap.

This determination needs to be made during design phase.

In the event that the roof insulation thickness increases due to minimum energy code requirements and meeting minimum roof pitch, roof curbs and penetrations may need to be replaced to meet roofing manufacturers minimum 8” flashing requirements. See Mechanical section for additional information mechanical roof curbs and penetrations.

All abandoned roof penetrations / curbs are to be removed and roofed over to minimize roofing penetrations and amount of roofing obstructions. Structural decking infill will need to be installed where abandoned roof penetrations exist to allow for new roofing system to be installed. See structural section for decking requirements.

All roof access ladders are to remain as is unless directed by COR for replacement to be included in scope.

3.3 Architectural Construction

Install new base standard EPDM roofing system to include 90 mil EPDM membrane, insulation with 1/2" cover board as per energy code requirements, ½” fire resistant cover board under insulation on top of structural decking and all flashings to include but not limited to flashing, counter flashing, expansion joint covers, reglets, scuppers, coping cap, piping penetrations boots and etc.

New scupper drains are to be installed to meet overflow requirements and are to be daylighted on exterior side of parapet. See structural section to account for water live load requirements in installing new secondary scupper drains to ensure roof structure can handle water live loads.

New roof shall meet the overall roof and drainage plan for each designated building.

New roof shall meet ASCE 7, UFC 3‐301‐01, ASHRAE 90.1 and any Tinker AFB standards.

New roof system will provide a 30 year No Dollar Limit Warranty with a 2” hail warranty. New expansion joints are to be installed to replace existing expansion joints.

New walkway pads to be installed to all serviceable items on roof.

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All remaining stone coping caps to receive new backer rod and sealant.

4. Structural Design Narrative

The structural work is required to aid the roof replacement. Analysis of the existing structure is required to determine structure is adequate for ponding loads. If the analysis reveals that the roof framing is overstressed due to ponding effects, new strengthening design and detail will be required.

4.1 General Design Parameters and Assumptions

4.1.1 Structural Steel

W and WT Shapes: ASTM A992 or ASTM A572, Grade 50, with special requirements per

AISC Technical Bulletin #3.

Other Rolled Sections and Plates: ASTM A36 or ASTM A572, Grade 50.

Square or Rectangular Tubes (HSS): ASTM A500, Grade B.

High Strength Bolts: ASTM A325, with compressible washer type direct tension indicators or twist of type tension control bolts.

Anchor Bolts: ASTM F593, Type 304.

4.1.2 Steel Design

Structural steel design will be performed in accordance with the requirements of the American Institute of Manual Steel Construction (15th Edition), AISC 360‐16.

4.1.3 Structural Loads

Dead Loads

Dead loads will be considered resulting from fixed construction, materials, and equipment. Dead loads will be determined and applied in accordance with ASCE 7‐16, and other pertinent standards and vendor‐supplied information.

Live Loads

Live loads are those loads produced by the use and occupancy of the building or structure, and do not include loads such as wind/seismic loads, rain loads, flood loads, or dead loads. Minimum uniformly distributed live loads of 20 psf will be as required by ASCE 7‐16.

Wind Loads

General: Wind loads for structural design of main wind force resisting systems and components and cladding shall be determined and applied in accordance with ASCE 7‐ 16, Directional procedure.

Wind Speed: The minimum 3‐second gust design wind speed shall be determined from Figure 26.5, ASCE 7‐16. A basic wind speed of 116 mph will be appropriate for the project location.

Exposure Category: Building exposure classification C, as defined by ASCE 7‐16, shall be used for this building.

Risk Category: Building risk category III, as defined by ASCE 7‐16, is required for this building.

Seismic and Snow Loads

Seismic loads shall be determined in accordance with IBC 2018.

Snow loads shall be determined in accordance with IBC 2018. The ground snow load shall be 10 pounds per square foot.

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Rain Loads

Rain loads and ponding load shall be determined in accordance with ASCE7‐16. Secondary effects from deflection to be included.

4.1.4 Load Combinations

Load combinations using strength design and service‐level combinations shall be as defined in

ASCE 7‐16.

4.2 Structural Demolition

4.2.1 Thru Wall Scupper

Demolish and remove opening in exterior wall as required to install a thru wall scupper.

4.3 Structural Construction

4.3.1 Thru Wall Scupper

Provide and install secondary steel angles as required to support new thru wall scupper.

(1) Steel shall be coated in a corrosion resistant material.

4.3.2 Capping Mechanical Openings/Infilling penetrations

Provide and install steel cover plate over existing opening to be capped.

(1) Plate shall be able to resist all roof loads.

Provide and install new steel cover plate or roof deck over existing openings to be infilled.

(1) Plate/roof deck shall be able to resist all roof loads.

4.3.3 Equipment/Pipe supports

See mechanical for discussion on equipment curbs.

Pipe supports shall be removed and replaced with new pipe supports. Pipe supports shall be designed in accordance with Tinker AFB standards.

(1) All penetrations, duct routing, conduit routing and equipment placement not on curbs shall be in general conformance to the representative set of details found in , Attachment of Rooftop equipment in High Wind Regions, FEMA.

(2) All pipe supports shall be structurally anchored to the deck.

4.3.4 Structural Roof Analysis

Provide an analysis of the existing roof structure to determine adequacy of system to resist loads per UFC 3‐301‐01.

(1) Existing roof does not contain secondary drains or proper slope. Thus, roof must be analyzed for ponding loads. Include secondary effects from deflection. If analysis reveals that the roof framing is overstressed, new strengthening design and detail will be required.

(2) Calculations shall be signed and sealed by a structural engineer in the state of Oklahoma.

(3) Any strengthening required shall be signed and sealed by a structural engineer registered in the state of Oklahoma.

5. Mechanical Design Narrative

The mechanical requirements for the project include (but are not limited to):

Replacement of existing primary roof drain fixtures.

Replacement of existing HVAC rooftop equipment roof curbs where required.

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Demolition of existing abandoned HVAC rooftop equipment and associated curbs/penetrations.

Replacement of existing condensate piping routed above the roof line.

Replacement of existing roof mounted pipe and duct supports.

5.1 Mechanical Demolition and Construction

5.1.1 Replacement of primary roof drain fixtures

Provide drainage calculations verifying that quantity and size of existing roof drain fixtures meets current codes, or calculations showing that an increase in size is required. New roof drain fixtures shall not be smaller in size/capacity than existing.

Storm drainage calculations shall be per IPC 2018, Chapter 11.

New roof drain fixtures shall meet the requirements of UFC 3‐420‐01 and UFGS 22 00 00.

Install new roof drain fixtures in the same location as existing. Connect to existing primary drain piping below roof. Match piping material to existing.

Insulate new roof drain bodies and piping back to point of connection to existing piping. Match insulation material to existing.

5.1.2 Addition of secondary roof drainage

Secondary roof drainage shall be provided via scuppers, leader heads, and down spouts.

See Architectural for additional information.

5.1.3 Replacement of existing HVAC equipment curbs

Wherever existing HVAC rooftop equipment curbs will extend less than 12” above the NEW line of roof insulation, the equipment curb shall be replaced.

Remove the existing equipment and protect during curb replacement.

Coordinate associated system downtime with the government/user and provide temporary HVAC if required, or if downtime will exceed one week.

New curb shall extend at least 12” above the NEW line of roof insulation.

Provide new insulated roof curb to match requirements of associated equipment. Refer to Architectural details for curb construction.

Where existing curbs are larger than the served equipment, provide new curbs to match the existing unit size. Patch the remaining roof opening as required. Refer to Structural for requirements.

Where existing curbs are larger than the served equipment, retain existing curb adapter for reuse and reinstallation on new curb.

Reinstall existing rooftop equipment on new curb. Extend piping and ductwork connections as needed to reconnect to existing distribution. Match materials and insulation to existing.

Reinstalled rooftop equipment shall be fastened to the new curbs in accordance with Attachment of Rooftop equipment in High Wind Regions, FEMA.

5.1.4 Demolish existing abandoned penetrations and HVAC equipment

Remove all existing capped roof curbs and penetrations that are no longer in use. Patch roof deck and provide new roofing/insulation.

Remove all existing mechanical equipment that is abandoned/no longer in use. Remove any associated ductwork and piping down to below the roof deck and cap. Patch any remaining openings and provide new roofing/insulation.

Confirm each piece of equipment proposed to be removed with the government.

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5.1.5 Replacement of existing PVC condensate piping

Survey existing rooftop HVAC equipment for connected PVC condensate piping. Remove and replace condensate piping with insulated copper piping of the same size.

Terminate condensate piping at existing termination point. If existing termination point is at a roof drain fixture, provide new routing to the nearest floor drain or receptacle such that condensate is discharged into the sanitary sewer system.

Coordinate routing of condensate drain piping within building with government to minimize impact.

Provide cleanouts at all 90 degree changes of direction.

Maintain minimum slope of 1/8 inch per foot.

5.1.6 Replacement of existing pipe and duct supports

All existing roof mounted duct supports shall be replaced. Provide new galvanized supports anchored directly to the roof structure to comply with Tinker standards. Duct supports shall be designed to resist uplift in accordance with Attachment of Rooftop equipment in High Wind Regions, FEMA.

Reinsulate and weatherproof existing ductwork where supports were added as required to maintain insulation integrity for all exposed ductwork routed across the roof. New insulation shall be UV resistant and sealed as required per UFGS 23 07 00.

All existing roof mounted pipe supports shall be replaced.

Where existing supports are anchored directly to structure, provide new pipe supports that are also anchored directly to structure.

Where existing pipe supports are not anchored directly to structure, provide new pipe supports that are UV resistant with galvanized steel channel with 100% recycled rubber base.

Gas lines to be supported per NFPA 54.

6. Electrical Design Narrative

The electrical requirements for the project include (but are not limited to):

Disconnection of existing HVAC equipment to facilitate roof replacement.

Reconnection of existing HVAC equipment after it is re‐installed.

Replacement of any damaged conductors and/or conduit to HVAC equipment.

Disconnection and removal of existing roof mounted flood lights and re‐installed of light fixtures in new work.

Disconnection and Reconnection/reinstallation of existing Lightning Protection system.

Test, inspect and re‐certify by the 3rd party for the LPS as required.

6.1 Electrical Demolition

Demolish/remove existing abandoned conduit.

For conduits that are to remain, remove any existing wood blocking or supports.

Disconnect existing HVAC equipment (power and controls) as required to allow for the removal of equipment for installation of new roofing materials.

Disconnect and remove existing light fixtures and store for reconnection in new work.

Remove existing conduits located near the parapet. Retain existing conductors for rerouting in new work.

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Disconnect and remove all existing PVC conduits penetrating through roof. Retain existing conductors/cables for rerouting in new work.

Disconnect existing LPS and retain all components/devices for reinstallation and reconnection in new work.

6.2 Electrical Construction

For conduits that are to remain, provide and install new rubber block supports, equal to the Dura‐ Blok line.

Reconnect existing HVAC equipment that has been reinstalled after completion of roof replacement.

Based on inspection, provide new liquid‐tight flexible metal conduit (LFMC) and conductors for connection to reinstalled HVAC equipment.

Reinstall and connect existing light fixtures removed under paragraph 6.1.4 above. Fixtures are to be elevated approximately 2’ above their previous existing mounting height.

Provide new conduits along the parapet where conduits are being replaced.

Reinstall existing LPS at same location. Test, inspect and re‐certify by 3rd party IAW NFPA 780, UL96A, and AFMAN 32‐1065.

Provide new steel conduits where PVC conduits were removed.

All new conduits shall be routed via existing route, where they are being replaced on roof.

All existing conduits being retained during demolition will be rerouted via replaced conduits.

All new conduit penetrations will be patched and sealed as required per specifications.

If such existing conductors are required to be extended for reconnection, contractor will be required to submit RFI if splices are permitted or replace the feeder entirety from device to panel source.

All electrical system will be required to be tested and ensure they are returned to original operations.

7. Fire Protection / Life Safety Design Narrative – N/A

7.1 Fire Extinguishers

The Contractor shall provide portable fire extinguishers suitable for the combustible present during construction. Where existing building extinguishers are blocked, removed or generally made inaccessible to the building occupants, supplemental extinguishers shall be provided such that a portable fire extinguisher is located within 75 feet travel distance of all areas of the building. The Contractor shall provide fire extinguishers per NFPA 241 Standard and shall be specific to the job being performed. This also includes when operating any internal combustion engine on or around the facility. The Contractor shall regularly inspect (a minimum of once weekly) portable extinguishers located within the work area to ensure that they are charged, free from damage and accessible.

7.2 Safeguards during Construction

All work associated with this project shall be performed in accordance with NFPA 241 Standard for Safeguarding Construction, Alteration, and Demolition Operations.

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7.3 Hot Work

All Hot Work associated with demolition and construction shall be performed in accordance with NFPA 51. Safeguard for Hot Work operations include but are not limited to the relocation of combustible storage, the use of fire resistive barriers to protect combustibles that cannot be relocated, the establishment of Fire Watch and the termination of hot work operations when fire protection systems are out of service. Additionally, Hot Work should not be performed when alternative methods can be employed to dismantle existing or assemble new systems.

7.4 Fire Protection Impairment Supervision

Fire protection impairments will be supervised and performed in accordance with UFC 3‐601-02.

8. Intrusion Detection System (IDS) Design Narrative – N/A

9. Access Control System (ACS) Design Narrative – N/A

10. Communications Design Narrative The Using Organization must submit a Work Order in Cyberspace Infrastructure Planning

System (CIPS) to provide the following. Work Request may be submitted to 72ABW/SCXP @ 72ABW.SCXP.projectmanagers@us.af.mil.

All communication equipment, such as antennas and associated cables/conduits will be removed and reinstalled by Government. All works must be coordinated with Government prior commencing works.

11. Phasing Plan – N/A

Appendix A Architectural Calculations and Cut sheets

New Roof profile:

0.5” Dens Deck

Rigid Insulation

0.5” High Density Cover board 90 Mil White EPDM

Appendix B Structural Calculations and Cut sheets

Dead Loads

Existing Roof Dead Loads:

1.5” Metal Roof Deck

2psf

4.5” Rigid Insulation 7psf

Build‐up roofing w/ gravel 6psf

1” Perlite 1psf

Waterproofing 1psf

MEP 3psf

Total 20psf

New Roof Dead Loads:

1.5” Metal Roof Deck 2psf

6” Rigid Insulation 9psf

0.5” Dens Deck 2psf

0.5” Cover board 1psf

EPDM 1psf

MEP 3psf

Total 18psf

Conclusion: New dead load is less than existing dead load thus existing structure is adequate for dead load.

Live Loads

Roof occupancy has not changed, thus live loads have not changed.

Wind Loads

Wind loads have not changed. Uplift forces will increase slightly from reduced dead load, but is negligible.

Rain/Ponding Loads Existing roof does not contain emergency backup drains or have a slope over 1/4”/ft. Existing roof slope is approximately 1/8”/ft. Code changes requires ponding load to be included in design.

Ponding Weight

62.4pcf*6”=31.2psf

62.4pcf*5”=26.0psf

62.4pcf*4”=20.8psf

Conclusion: Ponding load for water levels over 4” is greater than the roof live load of 20psf. Roof structure requires analysis to determine adequacy. Secondary effects from deflections shall be included.