SOW OWD ATCT HVAC.pdf

REPLACE CAB HVAC UNIT 08/28/2023

AIR TRAFFIC CONTROL TOWER NORWOOD, MA

REPLACE HVAC UNIT Page 1 of 8

STATEMENT OF WORK

REPLACE HVAC UNIT FAA

Air Traffic Control Tower (OWD) Norwood, MA

1. OBJECTIVE. Replace one Heating, Ventilating, and Air Conditioning (HVAC) packaged rooftop unit. Provide and install a Packaged Terminal Air Conditioner (PTAC). Provide two electric unit heaters (EUH) and only install one of the EUHs. Repair the existing roofing system and apply elastomeric protection coating.

2. FACILITY. The project is located at the following address:

A. Air Traffic Control Tower (OWD) 111 Access Road, Norwood, MA 02062

3. GENERAL. The Contractor must furnish all labor, equipment, and materials for replacement the HVAC equipment and the roof rehabilitation at the Air Traffic Control Tower in Norwood, MA. The following items are a summary of the project and provided solely for describing the general nature of the work. The contractor is advised that this is a fully operational facility, and any unscheduled interruptions may cause aircraft accidents and loss of life. The facility shall remain operational throughout the entire contract unless a coordinated shutdown is scheduled. The contractor is responsible for accomplishing all items of work identified in the applicable drawings, specifications, and provisions of the contract. In general, the work consists of the following (Contractor must provide and install the following):

4. SCOPE OF WORK.

A. ATCT HVAC replacement

1. Demolish existing rooftop unit

2. Install new rooftop unit must be 7.5 ton with a factory installed 27 KW electric heater

3. Reuse the existing vibration isolation stand and HVAC curb

4. Demolish existing supply flex ductwork

5. Install new duct work in the supply from the rooftop unit to distribution boxes

6. Provide continuous temporary cooling and heating throughout construction period

7. Construct new copper condensate line with a trap (clean existing roof drains)

8. Clean reused duct work and distribution boxes using a NADCA certified company

9. Demolish existing humidification system

10. Replace wall mounted thermostat (add opaque thermostat cover to protect from direct sunlight)

11. Testing, adjusting, and balancing (TAB) to be performed on system

B. Roof rehabilitation

1. Apply elastomeric roofing material, repair roof as needed

2. Roofing at tower shaft corners under catwalk.

3. Reroof ATCT roof deck with Elastomeric Coating.

4. Scrape and prep all railings at cab catwalk and cab roof levels and seal with elastomeric coating.

5. Remove all corner caps on steel mullions at ATCT cab and seal with elastomeric coating.

C. Package terminal air conditioners and electric unit heater replacement

1. Demolish existing ductless mini-split and install new 1 ton heat pump PTAC

2. Demolish existing electric unit heater and install new 3.7 kw EUH

D. Equipment and workmanship warranties

1. Include HVAC manufacturer’s warranty: 5 years on compressors and coils

2. Include labor/ installation warranty: 1 year on all parts and materials

3. Include roof warranty: 20 year on new roofing system

5. LIST OF DRAWINGS

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OWD-23000102-G001 COVER SHEET AND INDEX SHEET

OWD-23000102-C001 ROOF WORK

OWD-23000102-E001 ELECTRICAL ONE LINE DIAGRAM

OWD-23000102-E002 ELECTRICAL PANEL SCHEDULE

OWD-23000102-M001 MECHANICAL HVAC SCHEDULE

OWD-23000102-M002 MECHANICAL DUCTWORK DETAIL

OWD-23000102-M003 MECHANICAL PTAC SCHEDULE

6. MATERIALS.

A. Materials furnished by the contractor for this project shall be new, unless specified materials can be re-used.

All product to be installed to the manufacturer’s instructions.

B. Hazardous Materials. No materials supplied by the contractor for this project shall contain asbestos or lead-based materials. All SDS sheets must be provided prior to construction for all required materials.

7. SITE VISIT. Contractor must have crane operator visit site prior to submitting crane lift plan.

A. Point of contact:

1. Shrey Patel, Mechanical Engineer, (374) 952-8159

8. PERFORMANCE PERIOD. Complete all work within 60 calendar days of Contractor’s Notice to Proceed. Based on facility requirements, night work will be mandatory

9. MEETINGS. Attend 2 separate meetings at the facility/ virtual (CO/COR discretion) after contract award and prior to start of work. Meetings may be on different days and several days or weeks apart. All meetings are mandatory.

Meetings include:

A. Preconstruction:

1. Logistics, schedule, deliveries, mobilization, etc.

2. Contractor personnel

3. Submittal approval

B. Operational Risk Management/ Mitigation:

1. Personnel and facility safety requirements

2. Coordination and communication for outages

3. Use of volatile organic compound containing products require additional coordination

10. SECURITY. Site access is restricted. Contractor employees must be always escorted by an FAA badged employee

(COR). Comply with all facility security requirements and inspections. Facility is on federal property.

A. All personnel performing work under this contract will be subject to the security requirements of the facility

11. SUBMITTALS.

A. Materials and Equipment. Provide submittal data for equipment proposed for use. Electronic portable document format (PDF) files of manufacturer’s complete performance data and descriptive literature must be submitted to the Contracting Officer (CO) for review and approval. Highlight specific model numbers, styles, and types scheduled for installation. All equipment and material that are not in accordance with the contract drawings and specifications must be specifically so noted and highlighted in the submission.

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B. Material Safety Data Sheets (MSDS). The contractor must supply the COR with MSDS’s of each material 3 days before it is brought on site. The contractor must place all MSDS’s in a binder in an accessible location so that all employees on site must have access to them. The binder must be updated each time a new material is brought on site or when a material is taken off site. After submission of the MSDS, no product substitutions is allowed without prior approval from the COR.

C. Safety Plan. The contractor must be required to submit a plan, within 14 days after contract award, for maintaining a safe environment. The plan must include practices used to comply with health and safety requirements. The contractor must certify in writing that he has all appropriate safety programs which comply with all federal, state, and local regulations.

D. Accident reports: A copy of each accident report, which the Contractor or subcontractors submit to their insurance carriers, shall be forwarded through the COR to the Contracting Officer (CO) as soon as possible, but in no event later than 48 hours after the accident occurred.

E. Odor mitigation plan: Contractor must submit a plan for approval, 2 weeks prior to construction start, for maintaining odor free working environment. The plan must include practices to mitigation the odor from roofing materials. Plan must include but not limited to use of night work, sealing cab outdoor ventilation, and indoor odor monitoring.

12. INSTALLER QUALIFICATIONS.

A. The installing contractor must have been engaged in the installation, service, and repair of this type system for a minimum of 5 years. The installing contractor must have an established working relationship with the Unit manufacturer and have all required certifications.

B. Crane operator must have required certification and present them to the COR on site prior to crane use. Crane operation will be limited to the approved scope in the obstruction evaluation and lift plan.

C. Any work engaged in duties/ performance of rigging must be a Qualified Rigger. Employer must determine and designate in writing the qualified rigger(s) and the specific rigging tasks task for which they are qualified and provide qualifications.

13. PROJECT CONDITIONS

A. Full FAA Occupancy: FAA will occupy the site and existing buildings during entire project period.

Cooperate with FAA personnel during project to minimize conflicts with FAA's operations.

B. Work Hours:

1. The ATCT hours of operation are 6:00AM – 10:00 PM. Construction must occur between Monday through Friday on mutually agreeable dates, excluding holidays. Hours and dates are subject to change due to FAA operational requirements. Work must not impact operational time of Air Traffic operations. The contractor must coordinate all construction activities with COR to eliminate impacts that would adversely impact the functions of the Air Traffic Controllers. To preclude adversely effecting air traffic operations, it is anticipated that some construction activities will have to be accomplished at night. Night work must be conducted from 10 PM – 6AM for specific tasks as noted below or task directed by the FAA COR. (Based on local time)

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2. Any activity that is above the catwalk, obstructs any portion of the air traffic controllers view of the runway, produces odor/ off-gasses, or produces excessive noise for an extended period of time, must be done between 10 PM and 6 AM. Contractor must provide detailed plan to COR for each activity 1 week prior to activity start, for an exemption of these requirements.

C. Monday through Friday on mutually agreeable dates, excluding holidays. Hours and dates are subject to change due to FAA operational requirements. Work must not impact operational time of Air Traffic operations.

1. Night Work: Night work will be required for portions of the project that negatively impact the air traffic operations. All nightwork must be scheduled with FAA personnel prior to work. Accomplish all work during hours between 10:00 PM and 6:00 AM (local time).

2. Day Work: Maximize amount of construction activities for day work. Accomplish all work during hours between 7:00 AM and 6:00PM (local time).

D. Operational Risk Avoidance.

1. General. This facility provides services to assist in the control of aircraft movement, operates 16 hours a day, 365 days a year, and is vital to the National Airspace System. The building is densely filled with electric and electronic equipment. This facility is secured with locked interior and exterior doors. All work will be performed with the facility maintaining full operation.

2. Coordination of Work Affecting Operational Systems or Personnel. Coordinate all work that has any or may have any impact on any operational systems or personnel within the facility through the COR. Cease any work that is adversely impacting the operations of the facility or personnel and immediately report impact to COR; repair or restore any portion of the operational system that has been damaged or suffered diminished performance as a result of the Contractor’s activities.

3. Avoid actions deemed detrimental or increasing risk to the facility’s mission, occupants, or equipment.

4. Avoid activities that create objectionable noise, release detectable odors, or generate smoke.

5. Avoid activities that raise temperature or decrease air volume in electronic equipment spaces, electrical equipment spaces and other areas that would suffer potential failures or reduced performance from such changes.

6. All space temperature and air volume changes must be scheduled and approved in advance by the

COR.

7. Circuit Breakers and disconnect switches will be operated by FAA personnel only. Contractor personnel must not operate circuit breakers or any other electrical disconnecting device. FAA will lockout/tagout equipment to insure personnel safety while safeguarding facility operations.

Contractor must participate as an observer in lockout/tagout procedures in order to protect contractor as well as FAA personnel. Contractor required to submit lockout/ tagout plan for approval, prior to construction

E. Safety.

1. Perform all work safely and in accordance with the following requirements.

2. Comply with FAA Electrical Standards, FAA Safety Standards, National Electrical Code (NFPA 70), National Fire Code, OSHA, manufacturer’s recommendations, local, state, and federal regulations, other authorities having jurisdiction, and local facility requirements. FAA Standards are available on request.

3. Workers must use Personal Protective Equipment (PPE) as required by code, regulation, standard, or manufacturer’s recommendation.

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4. Operators of any heavy equipment or machinery must be properly certified.

5. Contractor to handle refrigerant according to local, state, and federal requirements; including, but not limited to the removal, storage, and disposal of the refrigerant in the existing HVAC system. All refrigerant recover equipment as well as personnel disposing of refrigeration/ AC equipment must have required certifications. Contractor to maintain recordkeeping requirements for persons disposing of refrigerant. See EPA 40 CFR Part 82, subparts A and F.

F. Coordination and Approval.

1. Coordinate with and obtain approval from COR for work schedule, hours, and activities on a daily basis. Coordinate high risk tasks with COR prior to work start. High risk tasks include, but not limited to outages, cutovers, crane lifts, and new unit startup.

2. Contractor must provide temporary sanitary facilities to be used by workers on site. These must remain on site for the duration of the contract. The contractor must provide their own portable shelter to be located on site. Final location will be coordinated with the local FAA staff and COR

3. Provide a suitable dumpster for construction waste. The Contractor must have container emptied with suitable frequency so that trash does not overflow and blow around site and adjacent property.

A cover is required and must be provided on the dumpster in order for the refuse not to blow out. The Contractor must be responsible for the timely, legal disposal of all construction waste.

G. Drawings. The work to be accomplished is described in the statement of work. The drawings are intended to provide a general layout of the new mechanical systems, roof repairs, and buildings areas. Contractor to verify all dimensions onsite prior to construction. The contractor to maintain redline drawings throughout construction to be provided to the COR and CO for project completion.

14. CLEANUP. Remove all debris, rubbish, scrap, dirt, and protective coverings from the work areas upon completion of the work shift each day. Site conditions throughout construction period will not impact site operations. The affected work areas must be thoroughly cleaned to their original condition at the end of each work shift. Site must be returned to original condition prior to project completion.

15. QUALITY ASSURANCE AND WORKMANSHIP. All work must be accomplished in a neat, workmanlike manner by skilled workmen regularly engaged in their respective trade resulting in an installation that is satisfactory in both function and appearance as determined by the COR.

16. WARRANTY.

A. All material, equipment, and workmanship provided in the project must be warranted for a period of one (1) year, from date of acceptance by the COR unless noted otherwise elsewhere in contract documents.

B. Provide a (5) year warranty from HVAC manufacturer for compressors and coils C. Provide a (20) year warranty from Roofing system manufacturer for new roofing system

17. HVAC UNITS.

A. Existing Unit. One Trane 7.5 ton packaged air conditioning unit (see appendix for equipment tag and pictures of existing unit).

B. Existing Unit Removal. Remove unit from the site and dispose of or recycle properly in accordance with

EPA, state, and local guidelines.

C. New Unit. Furnish and install new high efficiency 7.5 ton packaged air conditioning units with the following features, characteristics, and options. Contractor may submit equal which has been stamped by a professional engineer.

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1. Basis of Design: Trane model (TSJ090A3S0K**A1C0AB0A0B410a)

DX cooling High efficiency R-410A

7.5 Ton, Dual Compressor

208-230/60/3 Unit controls: Symbio 700 No communications interface: simple thermostat 27 kW (3 Phase) electric heat Manual outside air damper 0-50% High static motor Hinged Access Panels/ 2” inch MERV 8 filters Standard Coil with hail guard Through the base electric Unit mounted/ non-fused disconnect Powered convenience outlet Dehumidification coil: modulating hot gas reheat Low ambient controls (down to 0°F) Supply air smoke detector Clogged filter switch and condensate drain pan overflow switch Stainless steel condensate drain pan

2. Installation. Install rooftop unit level and square to the building on top of the roof of the cab. New package unit must sit on existing seismic curb and connect to existing supply/ return plenum. Connect power with the through the bottom connection using existing power conductors and conduits. New thermostat to be installed in the cab using new control wires in existing conduit.

3. Crane. A crane will be required to remove existing unit and install new unit on top of the cab roof. The use of crane will obstruct the view from the cab which will interfere with the operations of the tower;

crane work must be night work. Crane placement, maximum height, loading weight, and operation will be restricted to the obstruction evaluation. Contractor to submit a standard or critical lift plane 30 days prior to crane use. Lift plan to include, but not limited to, the following:

A. Personnel: roles, responsibilities, qualification, public persons or other trade personnel access or affected by lift

B. Area Preparation: load handling location and path of travel, blocking/cribbing, overhead lines, ground stability

C. Load Handling Equipment Considerations: capacity, configuration, obstructions, inspection, ground support conditions

D. Load parameters: weight, center of gravity, radii, and configuration E. Rigging: type, inspection, need for softeners F. Environmental Considerations: wind, storms, precipitation, power lines in area of travel or load swing, counterweight swing area barricaded.

D. Temporary equipment. Contractor must submit a plan on providing temporary cooling and heating throughout construction period. Cooling solution must provide 7.5 tons of cooling to the cab space without interruption of service; heating solution must provide 27 Kw of heating to the cab space without interruption of service. Plan must include an electrical consideration; service will only be provided from the circuit breakers providing power to the current HVAC unit. The use of a temporary breaker fed by the rooftop HVAC electrical conductors is recommended. Installation and demolition of temporary solution must occur at night if installation will negatively impact operations of tower.

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E. Ductwork. Replace all flex duct work (8in diameter), such that all pieces of flex ductwork has a maximum length of 6 feet. Extend hard line duct work such that flex duct can meet 6 foot requirement. Match existing duct materials when replacing or extending ductwork. Flex duct work must be insulated, and all (existing and new) hard line ductwork must have 2 inch duct liner. Ductwork replacement will impact tower operations due to ductwork being located in cab dropped ceiling; ductwork replacement must be night work.

F. Cleaning. A written work plan must be submitted by a NADCA certified cleaner, which must include scope of work, means and methods, schedule, product submittals, and SDS. All existing ductwork, grilles/ registers, distribution boxes, and plenums to be reused must be cleaned and sanitized.

G. Testing. Measure airflow, supply air temperature, and return air temperature in both cooling and heating mode.

Record test results. Have a third party TAB performed on the new system. Provide copy of test results to COR at time of test completion. Include copy of test reports in close out documents.

18. PTAC UNIT

A. Demolish existing ductless mini split that is servicing the second-floor equipment room. The condensing unit is mounted on grade outdoors on the north side of the control tower. The indoor unit is wall mounted in the second floor equipment room. Demolish both units, the refrigeration piping, the conductors and conduit between the two units. Dispose of the refrigerant according to local, state, and federal requirements. NEMA 16-5R receptacle, conductors to panel, and breakers in panel must remain to be reused.

B. Contractor must provide and install a 1 ton heat pump – packaged terminal air conditioner, with the following features, characteristics, and options. Contractor may submit equal which has been stamped by a professional engineer.

1 Basis of design: Friedrich FreshAire PVH12K a Heat pump utilizing a DC inverter b Total cooling 12000 BTUs c Total heating 970 watts d 208-230 Volts/ 60 hz/ 1 phase using a Nema 6-15 R plug e MOP of 15 amps and MCA of 4.1 amps f No supplemental electric heater g Install new filters after construction is complete h Provide 3 additional filters to FAA

C. Installation: Contractor must install new unit according to manufacturer’s installation instructions. Contractor must create a new wall penetration to fit the PTAC unit. Provide and install a compatible insulated wall sleeve according to manufacturer’s installation instructions; submit insulated wall sleeve for approval prior to installation. The penetration must be caulked on all sides and be weather resistant. There is limited space for installation due to a exposed structural element of control tower; submit a coordination drawing of the wall penetration prior to construction. Provide and install a wall mounted thermostat to control PTAC unit;

installation must include all control wires and conduit. Location to be field located with coordination of FAA personnel.

19. ELECTRIC UNIT HEATER

A. Demolish existing electric unit heater in the first floor equipment room. The existing unit is ceiling mounted, that is powered by Panel A, with a wall mounted thermostat. Demolish unit, ceiling mount, thermostat, and control wires between thermostat and unit; the power conductors and all conduit can be reused.

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B. Contractor must provide and install 3.7 KW EUH, with the following features, characteristics, and options.

Contractor may submit equal which has been stamped by a professional engineer. Reuse existing power conductors, conduit, and double pole 20 amp breaker from panel A to EUH. Install a new line voltage thermostat using manufacturer’s installation instructions in existing conduit. Provide and install unit using the manufacturer’s ceiling mount.

1 Basis of design: QMark MUH05-21 a 3.7 KW Electric Unit heater b 208 Volts/ 60 Hz/ 1 Phase/ 18 amps/ 10 AWG c 1/100 hp motor @ 1600 rpm d Provide and install manufacturer’s original ceiling mount.

e Provide and install manufacturer’s original line voltage thermostat

20. ROOF AND EXTERIOR ATCT CAB

A. Existing. The existing ATCT roof assembly is a Sika Sarnafil G410 adhered system over ½” dens deck, 3” ISO, and vapor barrier over a structurally sloped steel deck. There are sarnatred sand coated walkway pads adhered throughout the perimeter of the cab roof.

B. Contractor to apply manufacturer instructed number of coats of elastomeric roof coating or approved equivalent. Coating will be applied to flat roof, roof side walls, HVAC curb flashing, and roof hatch flashing according to manufacturer’s installation instructions. Work to include substrate preparation and sealing air leakage/ water intrusion pathways. Contractor to obtain manufacturer’s 20 year roof warranty.

1. Clean and prep ATCT and Base Building roof deck. Prime entire roof deck and flashings with Sika EP Primer or equal. After curing, apply Sika Roof Pro 641 resin basecoat or equal over roof and all flashings. Install Reemat fiberglass reinforcement set in a wet coat of Sika Roof Pro 641 resin base coat or equal and let cure. Apply Sika Roof Pro 641 or equal resin topcoat to the entire roof and flashings and let cure. Apply a third coat of SikaRoof Pro 641 resin for traffic surfacing spreading quartz aggregate over entire roof.

2. Once new HVAC system is replaced, the elastomeric coating be applied to the flash the new unit and produce a seamless, watertight roof system. Apply elastomeric coating to the vertical surfaces of the roof hatch. Work includes substrate preparation, and sealing air leakage/ water intrusion pathways.

Application must follow all of manufacturer’s installation instruction. Match the color of the new elastomeric coating to the existing roofing material.

3. Use same roofing system over upper parapet roof wall and down the façade of the control tower, continue on, and the lower parapet roof wall. During the application process, carefully remove and re-install the lightning protection system

4. There are areas that will require grinding away rust to prepare metal for adhesion to a sound substrate.

This would include railings on catwalk and cab roof, siding, and other areas where the liquid membrane will be applied. Replace existing caulk joints with Sikaflex 1A sealant or equal. Prime all steel with Sika EP Primer or equal and let cure. Apply Sika 641 resin base coat or equal. Install Reemat Premium set in a wet base coat of Sika Roof Pro 641 resin base coat or equal and let cure. Apply Sika Roof Pro 641 Resin top coat or equal

5. Use same roofing system under the steel catwalk on the failing EPDM roof system. Repair voids, tears, open seams and prep EPDM roofing at tower shaft corners. Clean membrane per manufacturer’s recommendations. Apply EPDM Primer and let cure. Apply Sika Roof Pro 641 Resin base coat, set in

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Sika Fleece 140 in wet base coat. Apply Sika Roof Pro 641 Topcoat or equal. This work may require removing and reinstalling catwalk grating and exterior cab wall panels as needed.

C. Products. Contractor to must submit all products for approval.

D. Attached will be the roofing site survey report from Sika

END OF SECTION

APPENDIX

Photo 1: Existing Trane roof top 7.5 ton package unit label

Photo 2: Rooftop Electric heat label

Photo 3 and 4: Side view of existing roof top unit

Photo 5: HVAC catalog - power requirements for existing unit

208/230 Volts Three Phase Standard Indoor Motor Oversized Indoor Motor Unit

Model No.

Heater Model no.

Heater Kw

Rating

Control Stages

MCA Max Fuse Size

MCA Max Fuse Size

SIKA CORPORATION • ROOFING

225 Dan Rd, Canton, MA 02021 Tel: 781-828-5400 · http://usa.sarnafil.sika.com

ATCT – Norwood 91 Access Road

Norwood, MA

Prepared By

Kennie Thompson

Sika Sarnafil

Report Date: 12/15/2022 http://usa.sarnafil.sika.com/

SIKA CORPORATION • ROOFING 2

Date: 12/12/2022

To: Charlie Beaton – Civil Engineer – Ops Engineering North

From: Kennie Thompson

Subject: Roof Survey on ATCT tower in Norwood.

Attendees: Charlie Beaton and Jim Caulfield (FAA), Gary Lewis (Sika), Paul Muller (Sika) and

Kennie Thompson (Sika)

Weather Conditions: Cool 40F dry and sunny day!

Purpose: Roof survey and core cuts to determine existing roof system.

Roof Assembly: Existing Sika Sarnafil G410 adhered system over ½ Dens Deck, 3” ISO and vapor barrier. Structurally sloped Steel Deck. Sarnatred sand coated Walkway pad adhered throughout perimeter of tower.

Project History/Background:

On 11/9/2022, Paul, Gary and I investigated the above referenced project with the direction and support of Charlie Beaton and Jim Caulfield of the FAA. At that time, we performed a roof survey for the ATCT tower at Norwood airport.

Observations:

Norwood ATCT tower roof is still functioning well with no reported problems.

Original roof was installed by

Top Tech roofing on 2007 and warranty expired 10/28/2017.

The perimeter of this roof has a sand coated Sarnatred Walkway

Pad that is still functioning. The sand coating has eroded over time and has accumulated on roof area and near drains.

SIKA CORPORATION • ROOFING 3

Deck is structurally sloped and no signs of ponding water was evident.

Removal of HVAC system will be in scope of project. Current penetration flashing is well above

Sika’s requirement of 8”.

Two core cuts were taken. One taken at drain level and the other at a higher level of the roof. We determined the steel decking was sloped as insulation was same thickness.

Standard roof hatch looks to be in good condition and functioning well. Flashing height is acceptable.

SIKA CORPORATION • ROOFING 4

The tower window seals and mullions on this project, in conjunction with the lower balcony will be the most difficult areas to address.

Sills show signs of rust. Some tower wire chase covers built into window frames have been modified, others need to be replaced.

Removal of tower wire chase covers and applying Sikapro 641 system before reinstalling existing mullions or refabrication necessary.

SIKA CORPORATION • ROOFING 5

Removal of existing surface rust will be necessary to expose bare metal for best adherence of liquid applied membrane.

Suggest Sikaflex 1A be used at caulk joints.

Apply Sikalastic Roofpro system up and over the window flashing.

When windows are replaced in future, suggest reactivating existing liquid membrane and re-flashing with Sikalastic again.

Some areas will require additional surface preparation prior to applying liquid membrane system.

SIKA CORPORATION • ROOFING 6

We suggest removing covers of wire chases and applying

Sikalastic 641 on entire perimeter of tower, top, sides and below. Reinstalling existing covers or refabricating new ones.

Use of staging may be necessary, not only for the mullion area, but also below at the balcony under the steel grating.

SIKA CORPORATION • ROOFING 7

Areas where Sikalastic Roofpro will be Applied!

Upper Roof over existing

Sarnafil system as described, including coating railings.

Apply coating over the upper roof edge, railings and continue down the façade and mullions.

Below balcony deck system – to be discussed more below.

Below the Steel balcony, there are areas of a roof deck that are covered in an adhered EPDM.

Some of the EPDM has become unadhered and will need to be repaired prior to installation of

Sikalastic Roofpro.

SIKA CORPORATION • ROOFING 8

Additional picture of EPDM unadhered.

The difficulty to address this area may be easier accessed with staging.

Staging may also be necessary for working on the mullions and above the cab windows.

Estimate staging from 30 to 50 feet high.

SIKA CORPORATION • ROOFING 9

Summary/Conclusion:

• Existing Sarnafil roof installed in 2007 and functioning well! Recommend the existing roof system is left in place. Pressure wash loose sand and debris from existing roof system. Once dry, apply Sikalastic Roofpro primer, fleece and 641 in a standard color below. An additional application of Roofpro sand can be added to create a traffic surface.

• Once the new HVAC system is updated or replaced, the Sika Roofpro system can be used to flash in the new unit and produce a seamless, watertight roof system for an additional

20 years.

• We recommend using the same Sikalastic Roofpro system over the parapet roof wall and down the façade of the control tower continue under all mullions (which will be reinstalled over liquid membrane).

SIKA CORPORATION • ROOFING 10

• There are several areas that will require grinding of rust to prepare metal for adhesion to a sound substrate! This would include window sills, railings and other areas where liquid membrane will be applied.

• The same system will be applied under the steel balcony on the failing EPDM roof system. Some of the existing EPDM roof system will need to be removed to allow strong bond between the new Sikalastic Roof system.

• We have asked a few local contractors to provide estimates to perform all of the work excluding recovering the existing installed Sarnafil roof system at the top of the tower.

This information will be supplied ASAP!