Design and Construction Standards

Thermal and Moisture Protection - Roofing
 

The criteria listed below represents Georgia Southern's observations and may be altered to maintain the architectural and/or structural integrity of the facility. Alternative roofing installations which have been proven to be effective against weathering and have shown durability shall be submitted to Georgia Southern for review and approval prior to abandoning this criteria.

The use of interior downspouts is discouraged. Where it is necessary to use interior downspouts, threaded pipe shall not be used.

Pitched standing seam metal roofs are the Georgia Southern standard for new construction. However, it is recognized that there are many existing low slope roofs on campus and the architectural design may require the use of some low slope roofing

 
Pitched Roofs (3/12 Slope or greater)

A preformed metal roofing system is the preferred roofing system dependent upon the building design. The acceptable panel texture is listed by manufacture:

Alcan Metal Building Products, Lancaster, PA
Architecture Panels, Inc.; Pontiac, MI; Roof-lod
Berridge Mfg. Co.; Houston, TX; Zee-lock panel
Binkley Inst.-lot; St. Louis, MO.
MM Systems Corp. Series 300 System; Tucker, Ga.
Metal Sales Manuf. Corp.; Jacksonville, Fla.
H . H. Robertson Co.; Pittsburgh, PA.
Merchant & Evens; Burlington, NJ.

Steel for Painting/Coating: Hot-dip zinc coated steel sheet, ASTM A 446, Grade A, except where higher strength required for performance,, G90 zinc coating, surface treated for maximum; coating performance.

Metal Finishes:
Color to match: Slate Grey
Texture: Smooth Finish.
Apply coatings to both sides of panels.

Fluorocarbon Polymer Coating: Glidden Nebular full-strength 70% "Canner 500" coating baked-on for 15 minutes at 450 0 F (232 0 C), a dry film thickness of 1.0 mils, 30% reflective glass (ASTM D 523), over 0.3 mil baked-on modified epoxy primer.

Durability: Provide coating which has been field tested under normal range of weathering conditions for minimum of 20 years without significant peel, blister, flake, chip, crack or check in finish, and without chalking in excess of 5 NBS units.

Installation: Metal roofs shall be installed to allow for expansion and contraction. The change in length of the individual panels will take place at either the ridge or the eave. Slip clips shall be used to allow for the expansion of the system. Exposed fasteners shall not be used.
 
Low Slope

Built-Up Roofs (Slope - 3/8"/FT Min 4"/FT Max): Built-up Roofing is the preferred roofing installation for the above noted slope conditions. A ballasted system is preferred over smooth surface roof system. This installation tends to require less attention to detail during installation (important with lowest bid contracting), ease of maintenance, and a more durable surface.

Materials
a. Felt: Type IV Fiberglass
b. Asphalt: Type III(1/4"/Ft-2"/Ft)
Type IV(2"/Ft-4"/Ft)
c. Metal Flashing: Aluminum
d. Base Flashing: Modified w/ Metal Backer
e. Preformed vent flashing and modified for drain penetrations are preferred over lead.
Preferred Manufacturers
Felt/Asphalt: GAF, Manville
Base Flashing: Supreme, Supplest

Modified Bitumen(Slope - 3/8"/FT Min 3/4"/FT Max): Modified bitumen installations are an acceptable alternate to Built-up Roofs. Close adherence to the above roof slopes should be observed unless the modified sheets are tacked in order to avoid slippage.

Preferred Manufacturers:
Supplest
Supreme
Nord Bedim
Garland

Single-Ply (Slope - 3/8"/FT Min): These are the least desired roofing systems listed and should be avoided unless there are no other alternates. The designer shall consult with Georgia Southern Physical Plant Facility Planning, Design and Construction Department prior to selection of a system.
A heat weld PVC system is preferred. Should the A/E choose to use a single-ply roof, the following items must be considered:
Hypalon requires close attention to prevent curing prior to installation. Once cured, the installation or any repairs require very close attention to cleaning and "reactivating" the membrane to affect adherence. The installations should not be made on Modular Buildings where the individual modules come with hypalon pre- attached to the roof substrate (and, thus, fully cured).
In general single ply installations work well when the owner is able to specify the installer or has the resources to check all seams and inspect the roof on a regular basis. We do not have that capability at Georgia Southern University.
If a single-ply system is used, the preferred method of installation is fully adhered with walk pads from all roof accesses to and around all roof top mounted equipment and items. In no case will a ballasted or inverted installation system be used. Heat welded seams are preferred over glued seams.

Materials: Thermoplastic/Polester Fabric or Reinforced PVC
Preferred Mfg.: DuraLast, Trocal, Carlisle
Material Warranty: 10 Years

Urethane Roofs: Foamed-in-place roof systems will not be considered for use at Georgia Southern University.
 
Steep Slope (Slope 4"/FT Min):

Other than metal roofing, shingles, due to their ease of installation, are preferred on steep slope roofs.

Materials
a. Shingles: Fiberglass based Asphalt
  Warranty: 25 Year Minimum
Preferred Maunfacturer Timberline Type Class A
b. Underlayment: Organic Felt type III, 30 lb.
  Preferred Maunfacturer GAF, Manville