Item No.: 4d_Supp 
Date:   September 13, 2016 
Terminal 91 Building C-173
Roof Overlay

Building C-173 Roof Overlay 
Building C-173 




Existing C-173 Roof Approximately 29 Years Old 
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Existing Roof Elements 


Abandoned mechanical unit              Underside of abandoned mechanical unit 

Existing Roof Top Mechanical Elements 
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Existing Deteriorated Roof Elements 

Underside rusted canopy area      Hole previously repaired with coating        Hole previously repaired with coating 




Rusted underside of roof panel    Previous repair of metal roof at rusted location      Mechanical room penetrations 
Existing Deteriorated Roof Elements 
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Incorporate Sustainable Elements 
Increase Insulation Value 
Utilize Reflective Overlay Material 
Recycling of Demolished Materials 
Durable Roof System that can last 30 years as specified 
The project will also consider: 
Bio filtration units at the downspouts

Sustainable Elements 
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Project Alternatives Considered 
Alternatives                          Description                             Cost
Implications 
[Solar] 
Alternative 1     Maintain Status Quo.                                           $9.8K 
Continue to pay maintenance cost. (Approximately $9.8K/yr) 
Alternative 2     Coat Roof with roll-on Coating System (10 year life)                      $2.34M 
Add Fall protection and Security ladders 
Alternative 3     Replace Roof with PVC membrane (30 year life)                        $1.56M 
Add Fall protection and Security ladders                            [$944K] 
Install Thin Film solar panels 
Alternative 4     Replace Roof with PVC membrane (30 year life)                        $1.56M 
Add Fall protection and Security ladders 
This is the recommended alternative 

Project Alternatives 
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Next Steps 
Complete Design              4th Quarter 2016 
Request Construction Authorization  1st Quarter 2017 
Construction Starts             2nd Quarter 2017 
Construction Complete          4th Quarter 2017 



Roof Overlay Project Schedule 
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