My neighbor moved in recently. A former owner had installed composite decking himself, and failed to leave any gaps between the boards. They are pressed right up against each other just as if it was a hardwood floor. Over time, they are buckling, and water cannot get through, some runs into the house during heavy rain.

I volunteered to help him repair the deck. The plan was to remove the screws (square-head, double threads and they do not want to budge). Then we were going to reset the boards with the proper spacing on the sides and at the ends. He got impatient, and started ripping the boards up from the joists. I told him to wait...

Someone else said to take a saw, and run it down the joints, leaving a gap the width of the saw blade. I tried this, and the blade overheated and warped. As it cooled, the blade straightened back out flat. So that is not an option right now.

Another person said to get a "wide-blade" for the saw, and try the same procedure again. Any suggestions on finding a "wide-blade"? Even if the wide-blade did work, it wouldn't help the ends of the boards where they butt-up against the next board. Seems that some would have to be pulled up to shorten the boards by 3/16" or so.

Anyone had this problem and found a solution? Any suggestions?

Thanks in advance.