Which testing standard includes requirements specifically for wall-to-wall joints?

The correct choice focuses on the testing standard that addresses wall-to-wall joints, which is ASTM E1966-UL 0079. This standard specifically evaluates firestop systems in a range of applications, including joints that occur at walls and ceilings, and it is designed to assess how these joints perform under fire conditions.

ASTM E1966 involves methods to determine the effectiveness of firestop systems in preventing the spread of flames and smoke through these transitions, ensuring a comprehensive approach to fire safety in building design. This makes it particularly relevant for assessing firestop installations in areas where two walls meet or where walls connect with other elements within a building.

The other standards mentioned focus on different aspects of fire testing. ASTM E119-UL 263 is centered more on fire resistance ratings of entire assemblies such as walls and floors rather than detailing specific joint requirements. ASTM E84 is used primarily for surface burning characteristics of building materials, and NFPA 701 addresses the flammability of textiles and films rather than firestop systems or wall-to-wall joint requirements. This context reinforces why ASTM E1966-UL 0079 is the precise standard for the question at hand.