Many homes have floors that are made of simple joists. Builders lay plywood over them to create a smooth floor. You need a plywood subfloor for the laying of tile and engineered wood flooring. A good subfloor improves the life of the flooring on top of it. Installing a subfloor can take a lot of time and effort but this preparation step prevents bigger problems in the future such as warping wood flooring or crumbling tile.
Measure the length and the width of the room. Multiply the measurement of the room to get the square footage. Use this measurement to order your plywood panels.
Lay the first panel so that the centre of the panel is on the centre joist of the room. All four corners of the panel should be resting on the centre of a joist.
Dry lay your other panels around the room so that the four corners are on the centre of joists. Stagger the boards so that none of the board's corners touch. Cut the plywood as necessary. Allow a 1/8 inch gap between all panels to allow for heat expansion.
Apply a nail every 10 inches along the joists and at 6-inch intervals along all edges of the boards.