ASTM C631 is the ASTM specification for bonding compounds for interior gypsum plastering, helping define the material expectations used when these compounds are selected and evaluated. It matters because bonding performance can affect how interior gypsum plaster systems adhere and perform during installation. For contractors, specifiers, and buyers, this standard provides a clear technical reference for comparing products and supporting consistent quality control in plastering applications.

What is ASTM C631?

ASTM C631 is the Standard Specification for Bonding Compounds for Interior Gypsum Plastering. As a product-focused ASTM standard, it is intended to guide the requirements associated with bonding compounds used with interior gypsum plaster systems. The document serves as a technical basis for product selection, procurement, and compliance review, helping users identify materials that are suitable for their intended plastering applications. ASTM C631 is commonly used as a reference point when evaluating material consistency and performance expectations.

Where is ASTM C631 used?

This standard is used in interior gypsum plastering work where a bonding compound is needed to support adhesion between gypsum plaster and the prepared substrate. It is relevant in building construction, renovation, and repair projects that specify gypsum plaster systems for interior surfaces. ASTM C631 is also useful in product testing, purchasing, and project specifications where a defined standard is needed to compare bonding compounds and align material choices with the intended application.

Why is ASTM C631 important?

ASTM C631 helps bring consistency to the selection and evaluation of bonding compounds used in interior gypsum plastering. By providing a recognized specification, it supports clearer procurement decisions, more reliable product comparison, and better quality control. This can reduce the risk of using materials that do not meet project expectations and can improve confidence in plaster system performance. ASTM C631 is therefore a practical reference for compliance-oriented purchasing and technical review.

• Specification for bonding compounds
• Interior gypsum plastering applications
• Product evaluation and comparison
• Quality control reference
• Procurement and compliance support