What is the required joint alignment for installing square edge or tongue and groove plywood subflooring?

When installing square edge or tongue and groove plywood subflooring, it is necessary for the joints to be staggered. This alignment is critical to the structural integrity and stability of the flooring. Staggering the joints helps distribute load evenly across the surface, reducing the likelihood of weaknesses or cracks forming at the joints. It also minimizes the risk of creating a continuous line of weakness that could be affected by moisture or movement over time.

By staggering the joints, you improve the overall performance of the subflooring system, as it enhances the connection between the panels and helps prevent the panels from flexing or shifting independently. This method allows for the formation of a more rigid and durable subfloor, which is essential in supporting the finished floor above.

In contrast, aligned joints can create a linear point of weakness, and overlapping or doubling up joints may introduce unnecessary complexity or irregularities in thickness. Thus, staggering the joints is the recommended practice for ensuring a reliable and robust subfloor.