(1) Asphalt shingles on sloped roofs shall be Class "A", fiberglass based, asphalt shingles with a recommended twenty-five-year minimum limited warranty over felt underlayment installed as per manufacturer's specifications minimum slope, four (4) in twelve (12).
(2) Peel and stick self-adhered ice and water shield synthetic underlayments are recommended along:
(A) The roof perimeter;
(B) Valleys; and
(C) Penetrations.
(b)
(1) Wood shingles shall not be used on buildings unless approved in writing by the Design Review Section.
(2) Any shingles used shall carry the "B" classification as listed by UL Solutions.
(3) Minimum slope — four (4) in twelve (12).
(c) Metal roofing systems on sloped roofs in excess of one (1) in twelve (12) slope (minimum two (2) in twelve (12) (+) slope preferred) are acceptable when properly detailed and specified.