ASTM C981 is the standard guide for design of built-up bituminous membrane waterproofing systems for building decks. It is used to help define how these waterproofing systems should be planned and selected so they perform reliably in deck applications. By focusing on design guidance rather than a finished product requirement, the standard supports clearer decision-making for project teams, helping reduce the chance of compatibility problems, leakage concerns, and avoidable installation issues.

ASTM C981 standard overview

ASTM C981 provides a technical guide for designing built-up bituminous membrane waterproofing systems intended for building decks. Its purpose is to support informed design choices for membrane-based waterproofing assemblies, with attention to how the system is arranged and applied in practice. The standard is relevant to projects where a bituminous membrane approach is selected and helps frame expectations around design considerations, materials coordination, and system suitability. As an ASTM standard, it is often used alongside project specifications and quality requirements.

Where is ASTM C981 used?

ASTM C981 is commonly used in the design and specification of waterproofing systems for building decks where built-up bituminous membranes are considered. It is relevant in project planning, submittal review, and technical coordination when a deck waterproofing assembly must be selected or evaluated. The guide may also support communication among designers, contractors, and material suppliers so the proposed system aligns with the intended application. In procurement and documentation workflows, it helps establish a consistent basis for system design.

Practical importance of ASTM C981

The practical value of ASTM C981 is that it helps bring consistency to the design of built-up bituminous membrane waterproofing systems. That can support better compliance with project requirements, more reliable product evaluation, and improved quality control during selection and detailing. For owners and specifiers, the guide may reduce uncertainty when comparing waterproofing options for building decks. For contractors, it can help clarify expected system design considerations before installation begins, lowering the risk of avoidable coordination issues.

• Design guide for built-up bituminous membranes
• Focused on building deck waterproofing
• Supports specification and submittal review
• Helpful for system selection and coordination
• Useful for quality and compliance checks