Wood Deck Boards Cupping

There are a number of ways to prevent this and fix your problem and make your deck last longer.
Wood deck boards cupping. This article series explains the causes of cupping in wood boards wood board right side up advice for steps decks ramps concluding which side of boards should face up or down bark side down or bark side up in some cases when building a deck or exterior wood stairs. The board will shrink and warp in the opposite direction of the rings in the wood. This article series explains the causes of cupping in wood boards wood board right side up advice for steps decks ramps. The problem of deck boards cupping is common but it should not be happening.
But when it rains and the board warps water collects in the concave shape and pools there. This has to do with the board s reaction to moisture and the heat of the sun. The result is either a cupping of the wood or a crowning depending on which way you face the board. From what you are describing there could be a few different reasons why your deck is acting the way it is and the most likely cause is the way the boards are nailed down.
In the case of cupping the moisture content is different on the top surface compared to the bottom surface. A board that is correctly installed right side up or bark side down will form a crown and allow water to run off the edges. This article explains the causes of wood board cupping and gives advice concluding that unless a board is already badly cupped or has a bad side when construction of outdoor decks and wood stairs you should place. Bark side up or down on exterior wood decks stairs.