NIGP 77093: Waterproofing Membrane and Base Sheet

NIGP 77093 Waterproofing Membrane and Base Sheet, an Item code, encompasses the supply and installation of single-ply and modified bitumen roofing membranes, base flashings, and related weather-sealing components on municipal, school, county, and institutional buildings. State and local governments procure this work primarily through general construction contracts for roof replacement and renovation projects, where waterproofing membranes represent the primary load-bearing weather-protection component of commercial roofing systems. Issuing bodies include city engineering and public works departments, county facilities and courthouse offices, school districts, community colleges, special-purpose districts such as wastewater treatment authorities, and tribal governments. Recent solicitations reflect consistent year-round demand across geographies, with cities and counties treating TPO (thermoplastic polyolefin) and modified bitumen systems as interchangeable baseline specifications, though some jurisdictions specify or pre-approve specific manufacturers such as Carlisle SynTec, Firestone, GAF, Johns Manville, Duro-Last, Sika Sarnafil, and Soprema to ensure warranty continuity or documented system performance. Mandatory pre-bid meetings and site visits are standard, and most awards emphasize lowest responsive and responsible bid rather than best value, though some larger projects weight qualifications and experience heavily.

Activity clusters in the Southeast (Georgia, Florida, Texas, South Carolina) and the Mountain West (Colorado), with significant secondary activity in the Upper Midwest (Wisconsin) and Northeast (Connecticut). Representative recent opportunities include the City of Madison Engineering's Normal Hall Roof Replacement (RFB 15026-0-2026, bids due August 6, 2026) for asphalt shingle and underlayment replacement on a 3,600 square-foot historic pavilion roof; San Jacinto Community College District's Building S15 Roof Coating and Envelope Repairs (CSP 26-12, proposals due May 6, 2026, approximately $1,900,000) for modified bitumen restoration and recoating on 43,000 square feet; Harris County Precinct 2's Leonel Castillo Community Center Roofing Replacement (ITB 26/0102, bids due June 15, 2026) requiring complete TPO membrane system removal and installation with five-year workmanship and twenty-year manufacturer warranty; the County of Santa Clara's as-needed roofing repair services (ITB-PRC-FY26-0588, bids due July 7, 2026) and Vasona Admin Building Roofing Replacement (ITB-PRC-FY26-0704, bids due June 18, 2026), both mandating California C-39 licensing; and Chatham County's TPO membrane purchase and installation at the Records Center (Bid 2600613, bids due June 18, 2026, 40,800 square feet) with 30 percent M/WBE participation goals and prequalified manufacturers limited to GAF, Firestone, and John Manville. DBE, M/WBE, HUB, and local-vendor preferences appear in 20–30 percent of recent solicitations, particularly in Texas, Georgia, and California jurisdictions.