Having a decking in your backyard will add value to your house. When you want to install decking, you will have to choose between different decking boards. There are composite decking and timber decking. Aside from that, there is a plastic decking. These deckings are good for outdoor space. But the decking boards perform better than one another. For example, wood decking will warp after you have installed it. That is why decking makers developed composite decking and advertised it as warp-free. But some homeowners are complaining about that composite decking warp. Will composite decking boards warp?

What Causes Warping in Decking?

Warping occurs when the surface of your decking becomes hot and gradually becomes distorted. The cause of warping in decking is a thermal expansion or changing temperature. Your plastic wood composite will warp if your decking boards absorb heat and expand. 

The heat will cause a household material to become flexible or soft. When the decking is flexible when hot, it will eventually become cool. Cooling of the decking will leave the distorted decking in an undesirable shape. A warped decking will not be straight like unwarp decking. 

If you walk on a warp plastic wood decking, you won’t be comfortable. Aside from distorting the surface of your decking, warping will reduce durability. When the boards of your decking are removed, the decking will eventually fall apart. 

What About Composite Decking?

Composite decking is a synthetic material that differs in property from wood decking. One quality of plastic wood composite is that it is durable and made to resist the elements. One weather element that composite decking will resist is heat or fluctuating temperature. 

The surface of your composite decking boards will become hot when the sun shines on them. Like most decking material, composite decking will absorb heat. But unlike rigid wood decking material, the heat will not make the surface of your decking shrink. When plastic wood composite becomes hot, it will become flexible.

 A flexible decking can expand easily. If a decking expands, it will increase in size. Aside from that, a flexible decking can easily be removed from the joists. Composite decking will expand like timber decking, but it won’t warp like timber. But this does not imply that composite decking cannot warp. 

Why Composite Decking Can Warp

Will My Composite Decking Boards Warp

Plastic wood decking can warp if it expands and touches a fixed surface. For example, this can occur if you install your composite boards close to your house and the boards touch the wall. If the composite boards expand, they will touch the hard surface of your home. 

When this occurs, the boards will warp or sag because they cannot push the hard surface. Instead of pushing the wall, the boards will act against themselves. What this implies is that they will be forced to be too close to one another. This tight packing will eventually make the decking boards go out of their place.

 This implies that if you fix your composite decking to the joists with clips, the boards will leave the clips. So, instead of having a straight top composite decking, you will have a rough top decking. Some of the plastic wood composite boards might even be removed from the joists.

How to Prevent Warping in Composite Decking

Remember that we mentioned that composite decking makers are advertising their plastic wood decking as warp-free decking. True, composite decking was designed to resist the elements but whether your plastic wood composite boards will warp depends on installing it. 

During building plastic wood decking, some homeowners try to save cash by installing the boards themselves. That is why most homeowners that have little experience have tried to install their composite decking. When this occurs, homeowners sometimes make mistakes. 

One mistake homeowners make when installing plastic wood decking is that they don’t add the right space between the joists and the boards. Spacing your composite boards is crucial as it gives the boards enough space to expand. 

For example, if there is space between your composite decking boards and your house’s wall, the boards will not touch the wall when it expands. If you leave the right space between the boards, they will not touch one another as they expand.

 So, what is the right amount of space to leave between composite boards? When building your plastic wood decking, you should leave at least 5 mm space between the boards and 15 mm space between the boards and wall.


Your composite decking boards will warp if you don’t leave the right amount of space when installing the boards. If you space the decking appropriately, the composite decking will not expand.

Leave a Reply

Your email address will not be published.

Your email address will not be published. Required fields are marked *