What is the maximum allowable twisting (rotation) of horizontal framing members due to the weight of glass?

The maximum allowable twisting or rotation of horizontal framing members due to the weight of glass is indeed 1 degree. This specification ensures structural integrity and proper performance of glazing systems. Glass panels are heavy and can create significant loads on framing systems. If the horizontal framing members twist beyond the allowable limit, it could lead to misalignment of the glass, increased risk of breakage, and failure of the framing.

Limiting the rotation to 1 degree helps maintain the design parameters and assures that the glass is adequately supported and functioning as intended. It is a critical factor in ensuring that the system can withstand stress, environmental factors, and changes over time without compromising safety or aesthetics. By adhering to this standard, glazing contractors can provide a more reliable installation that mitigates risks associated with improper framing alignment.