Reasons Why Composite Deck Can Warp

M. John
Why composite deck can warp

Installing ultra decking in your outdoor space can make your home visually appealing. Composite decking does not because warp like wood decking. That’s why homeowners prefer installing composite decking in their homes. But some people still complain that their composite decking warps. Can this be true? If so, what are the reasons why composite decking warps?

What Cause Warping in Deckings

Reasons Why Composite Deck Can Warp

Heat can cause a deck to warp. When there are temperature changes, it causes the decking to warp. Warping occurs when the decking’s surface is exposed to sunlight. The decking becomes hot and starts to distort gradually.  It happens during thermal expansion when the decking absorbs heat from the sun and expands.

The heat from the sun causes the decking to be flexible. And when it eventually cools, the decking shape will be distorted. It will not look the way it was before the thermal expansion of the decking occurs. The decking will be left distorted because of the heat. The board won’t be as straight as it was before it warped. What about composite decking? Can it warp too?

Will Composite Deck Warp?

Composite decking consists of wood and plastic material. It differs from natural wood decking. Composite decking is a synthetic decking material. It is known for its high durability compared to wood and plastic decking. Like other decking types, composite decking can also absorb heat when exposed to the sun. When this happens, composite decking becomes hot and flexible.

However, composite decking will expand when it becomes hot and flexible. The composite decking will not shrink like wood decking but will only expand. When composite decking expands, it will not warp like timber decking. Warping of composite decking can only occur if it is not installed in the right way. What are the reasons for a composite board warp?

Reasons Why Composite Decking Can Warp

The reason why wood-plastic decking can warp is if it expands and touches a fixed surface. It can happen if the composite board touches a wall. If the board touches the wall, it will make the boards too close to each other. The composite boards won’t be able to go further. It is what causes the composite decking to warp.

Apart from that, the tightness can also make the decking shift from its original position. When the composite boards shift from their original position, they will be removed from the joist. Can you prevent composite decking from warping?

How to Prevent Warping in Composite Decking

The way you install your composite decking will determine whether it will warp or not. Composite decking will not warp like wood decking, given that you follow accurate guidelines during installation. It is changes in temperature that causes composite decking to expand. Composite boards are designed to resist the elements which can cause them to warp.

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Quality composite decks offer resistance to warping, they shine

Warping of the composite decking will only occur if there is no spacing between the boards. When installing composite decking, ensure that the decking is appropriately spaced to allow it to expand freely. The gaps between the boards will prevent it from being tightly close to each other when it expands. When there is space between the composite board, the board will expand freely without warping.

To prevent warping, ensure the decking is fixed by a composite decking professional. The decking expert will leave gaps between the decking to allow for expansion. When installing composite decking, experts recommend leaving a space of 5 mm between the composite deckings. In addition, a space of 15 mm is also recommended between composite decking and a wall.


The reason why the composite decking can warp is if there is no space between the composite board. Decking experts recommend that there should be a gap of at least 5 mm between the deckings.

Tags: decking warping, Reasons decking warp

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