The new house has been framed in the rain and now the sub-floor sheet edges are swollen and raised. These seams must be sanded flat to make the sub-floor a flat plane, suitable for the new floor.
This step, especially with pre-finished flooring where no sanding will take place after install, is important so there is no visible telegraphing of the raised edge. As the floor board is installed over this raised area, the board follows this contour.
Just another step that’s built into every floor!
