Chipboard is a form of plywood made by pressing and gluing hundreds of small wood chips together. This type of plywood is cheaper than regular plywood made from large veneers of wood and a little less sturdy. However, it is perfect for some jobs and is often used as an under-layer for flooring materials and roofing. To lay this board you need to take the following steps.
Make a mark on the wall above every joist in the area where you are going to be laying the chip board. Use a pen and ruler to make the mark. Do this for both sides of the joist on each wall. You will have opposing marks on both walls for every joist when finished.
Set your stack of chip board close to the area where you are laying the board. Chip board is light, so you will laying it by hand, but you do not want to spend time and energy walking back and forth to the pile of chipboard every time you lay a new piece.
Set the first chip board onto the joist and set it flush against the corner or edge of the area. Place one end of a chalk line at one of the marks you made in step 1, then extend the chalk line across the chipboard to the other mark on the other side of the wall. Then snap the chalk line to distinguish where the joist is.
Hammer a nail into the center of the chipboard along one of the joists, sinking the nail into the joist. Then nail in another nail 6 to 8 inches away into the joist. Continue until you have a nail spaced every 6 to 8 inches along the entire joist.
Move to the joist under the chip board sheet and repeat step 4. Be sure to hammer in your nail from the center, as chip board will fragment and shatter if you nail to close to the corner when you first begin.
Cut the next frame board in half. Set this piece of chipboard alongside the first piece and make it flush with the edge. The reason this one is cut in half is so the chipboard sheets are staggered and the seams do not run across the entire roof. Professional carpenters take this extra step, because it is considered a neater way to complete the job. It is not necessary for an underfloor layer.
Then repeat steps 4 and 5 to secure the chipboard to the joists. Repeat this step until the entire surface is covered. Cut the pieces to the needed size using a table saw when you reach the end of the work surface.