CCAC Bid 1095 - Replace Roof at Library Building - Alleghen…

Community College of Allegheny County Pittsburgh, Pennsylvania

2022 Library Roofing Project

3.02

PREPARATION

A. Clean substrate of dust, debris, and other substances detrimental to roofing installation according to roofing system manufacturer’s written instructions. Remove sharp projections. B. Prevent materials from entering and clogging roof drains and conductors and from spilling or migrating onto surfaces of other construction. Remove roof-drain plugs when no work is taking place or when rain is forecast.

3.03

JOB CONDITIONS

A. Prior to the use of any roofing material, consult Material Safety Data Sheets for applicable cautions and warnings. 1. Do not use oil or bituminous base roof cement with thermoplastic materials. 2. Do not install membrane directly in contact with new or resaturated asphalt. 3. Do not expose membrane or accessories to temperatures of 180 degrees Fahrenheit or above. 4. Do not allow waste products (petroleum grease, oil or solvents, etc.) or direct steam venting to come in contact with the roofing system. Any exposures not typical for normal roofing installation must be presented to Tremco Inc. for assessment of any impact on the performance of the roofing system. 5. Do not install membrane directly in contact with coal tar roof surfaces. a. Install polyethylene vapor retarder ply (minimum 10 mil) under new insulation layer when thermoplastic membrane system is installed over existing coal tar roofs. 6. Ponding conditions will adversely affect performance of the roofing system. Where

positive drainage does not exist, water removal from roof surface should be facilitated by lowering drains, and/or installing additional drains, tapered insulation, or an approved lightweight insulating concrete slope system.

3.04

GENERAL INSTALLATION REQUIREMENTS

A. Install thermoplastic roofing membrane system according to roofing system manufacturer’s written instructions and applicable recommendations of ARMA/NRCA’s “Quality Control Guidelines for the Application of Thermoplastic Roofing”.

B.

Install roofing system per manufacturer’s published specifications manual.

C. Coordinate installation of roofing system components so insulation and roofing plies are not exposed to precipitation or remain exposed at the end of the workday or when rain is forecast.

D. Provide water cutoffs at end of each day’s work to cover exposed ply sheets and insulation. Water tightness of the water cutoffs is the subcontractor’s responsibility.

07540-6 THERMOPLASTIC MEMBRANE ROOFING

February 2022

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