How Do You Keep Deck Boards from Cupping

Decreasing the distance between your deck joists means that your deck boards are secured in more locations, span a shorter distance, and help prevent any unwanted cupping or warping. This helps solidify the deck overall and helps hold the structure together more firmly.

How do I stop decking cupping?

The best prevention is to allow ventilation by spreading a healthy layer of coarse gravel over a plastic membrane that allows the rain water to run away and then dry. Skirting the lower sections of the deck also enables moisture to be trapped under the deck. Tops dry, bottoms don’t = Cupping.

How do you keep timber from cupping?

Cupping: any cupping is temporary and can be corrected by wrapping the timber panel in plastic and then storing it on a flat, dry surface away from any wind, rain or direct heat. To avoid future cupping problems, the timber needs to be envelope-sealed (top, bottom and sides) with at least two coats of sealant coating.