Avoid anything thinner. Thickness influences not only the stiffness of the siding but also its thermal stability. Thin panels can bulge and buckle, and those thinner than .040 in. Thickness is only one of the factors affecting stiffness, but it s a big factor when comparing competitively priced panels. The stiffer the panel, the better it will bridge irregularities in a wall, so a heavier panel is a good idea when going over uneven older siding.
Rigid panels are also better at surviving high winds.
Beefing up the nailing hem, the slotted section of the panel that s nailed to the house, is another tactic that adds rigidity. As its name implies, it can be nailed tight, even by using a roofing stapler. This speeds installation and yields a straight wall with improved wind resistance. The siding s profile also influences stiffness. Just because consumers seem to be getting used to vinyl s traditionally bland appearance doesn t mean manufacturers have stopped trying to rival the look of classic wood.