Posted on July 25, 2017July 25, 2022How to level an old sagging floor These 2x4s ribs are 12 inches on center cut to fit the curve of the floor are level on topNew 1x12 inch heart-of-pine tongue and groove barnboardsShowing the barn boards being installed over the ribsYou can see the 3 inch sag from one side of the room to the otherUsed 2 inch cut nails used to hold down the flooring Finished with a custom stain to make the floor looked weatheredSealed with 2 top coats of polyurathane