 And you're supposed to put the nail in the middle of the slot, and you're supposed to not drive it tight to the building. You're supposed to let that siding breathe or move a little bit because vinyl has a very high expansion ratio. So when the sun hits it, especially the sides of your house that are on the south side and the west side, when the sun hits that, if the siding is on too tight, it's going to buckle and get real wavy and ugly looking.