Final answer:
In conventional light-frame construction, end joints in double top plates must be offset by at least 48 inches, following prescribed construction provisions for stability and load distribution.
Step-by-step explanation:
Under the conventional light-frame construction provisions, end joints in double top plates shall be offset not less than 48 inches. This ensures stability and the proper distribution of loads across the structure. The construction provisions commonly follow the International Residential Code (IRC) or similar standards, which dictate that the end joints between the top plates of a double wall should not coincide, to maintain a continuous tie across the top of the walls for structural support.