The type dimension of the Below‑Grade Waterproofing market is defined by the chemical and physical nature of the sealing system. Cementitious membranes dominate due to their ease of application, low cost, and compatibility with concrete substrates, contributing roughly 40% of total volume. Bituminous coatings, valued for their flexibility and resistance to hydrostatic pressure, account for about 25% and are preferred in high‑traffic parking structures. Polyurethane sealants, offering rapid curing and superior elongation, capture near 15% of the market, driven by demand in retrofit projects where downtime must be minimized. EPDM and other synthetic rubber membranes, noted for long‑term durability in aggressive chemical environments, represent roughly 10%, mainly in industrial complexes. Emerging Hybrid systems that combine cementitious bases with polymer modifiers are gaining traction, currently holding around 5% but projected to expand as performance requirements tighten. Each type’s share reflects its alignment with cost constraints, installation logistics, and performance criteria, collectively shaping the overall market size.