Horizontal fences tend to be more expensive than vertical fences because they require a higher grade of lumber for the fence boards to reduce the possibility of sagging. Even so, like any horizontally-oriented board, they may sag over time.

How do you stop a horizontal fence from bowing?

Install backrails on the fence no more than 8 inches from the top and bottom of the fence to prevent warping. For fences taller than 6 feet, install another backrail in the middle. At 8 feet, two backrails should be installed in the middle to further prevent warping.

Will horizontal fence warp?

Most woods will warp slightly over time. That's why we often recommend using tongue and groove planks when building a horizontal fence, as the planks will be nested together to help minimize warping. However, when using wood to build a slatted fence… There are things you can do to help minimize warping.