Sorry if this doesn't belong here.
I am about to insulate my crawl space. The width between joists is 18 inches. I can only find 15 and 23 inch batts. I went ahead and bought the 23". Should I just fold the extra down the sides of the joists? Or would it be worth it to cut the extra 6" off and piece it together and use it? Would stuffing extra insulation between joists cause any negative effect from compressing the insulation?