Division 7 Thermal and Moisture Protection
- Fiberglass batt insulation shall be installed to minimize exposed fiberglass in areas needing to be accessed for inspections, maintenance, etc. Designs should encapsulate fiberglass using foil or pre-applied backing, plastic or gypsum board covering.
- Rigid roof insulation shall be specified at its “5 year aged R value”.
- Single-ply roofing systems (60 Mil) should be specified for low slope (less than 4 in 12 pitch) applications. Fully adhered systems are preferred. Ballasted systems must be approved in advance by CPCC. Mechanically fastened systems are not acceptable. Provide a 20 year warranty. Determine in the Design Development phase if a light colored membrane would be cost effective relative to HVAC long term operating costs.
- Ballast (if approved) should be clean, river washed gravel meeting ASTM-C-136.
- Built up roofing systems are also acceptable for low slope situations. Specify a four ply system with a 20 year warranty.
- Specify service walkways (minimum 2’0” wide) appropriately located to service critical roof top equipment from the roof access.
- Asphalt shingles should be a heavy grade architectural grade with a 30 year warranty. Avoid 40 year shingles. Avoid use of ridge vents and shingles in valleys that give the roof a residential appearance. Use metal (copper preferred) flashing in the valleys.
- Roof leaders and/or downspouts shall tie directly into underground storm drainage system.
- Wide metal copings (greater than 10” wide) have a tendency to “cup” with age and use, and become a vulnerable part of the wall system. Provide continuous support under the sloped metal coping, or provide a more durable coping like precast concrete or stone.
- Specify roof hatches that are insulated and lockable. Roof hatches must be accessible from a secured, non-public room. Access ladder or steps to the roof hatch must have a non-skid surface.
- All roof areas need to be accessible from inside the building. ( Some small low one story roofs may be exempt from this requirement if approved by the Construction Director.) Design at least one interior fire stair to continue to the roof level and provide a service type insulated roof hatch (approx. 3’ x 6’) or as required by code.
As a minimum, provide a 60 mil unreinforced EPDM waterproofing system. Specify and obtain a 2 year (parts and labor) warranty from the Installer, and a 20 year warranty from the manufacturer.