Do You Leave Gaps Between Composite Decking Boards?

Henry A
gaps between decking

Installing Ultradecking is possible without any professional help, especially if you have prior experience and knowledge in building. However, in the construction process, there are many small yet crucial details that you have to observe and follow. These aspects will affect your decking, especially its longevity and durability. One of the most important things that many forget or don’t realize is to leave gaps between composite decking boards. But the question is, do you need to do it? And why is it so important?

Decking Spacing and Why It’s Important

When you install composite decking, especially if you do the DIY route, you have to remember to leave a gap between composite decking boards. Many people who try to build deckings for the first time often forget about this crucial detail. But the question is, why is it critical?

One of the main problems with decking is the expansion and shrinking of the decking boards. While not severe as wooden decking boards, some composites will still expand and shrink slightly under certain circumstances. Some boards do when exposed to high temperatures, while others are prone to moisture. However, the former is more common for composite decking boards.

When your decking shrinks, it can cause some accidents in your home. The gaps may become too big that some people may trip when walking on the decking. With too much air, it can also decrease your decking’s resistance to fire.

On the other hand, if there’s not much room for decking boards to expand, which they will eventually do, they can create friction and damage each other. Worst case scenario, due to the pressure from the expansion, the decking boards may warp.

Aside from that, decking boards that are too close to each other don’t drain water as fast as ones that have sufficient spacing. When cleaning the decking, dirt, pollen, and debris can also get stuck in between the tight spaces of your decking boards. Not only will it promotes the growth of moulds and mildew, but it can also be a cause of decking board warping.

For all the reasons mentioned above, leaving gaps in between your decking boards is critical. It can either damage your decking or preserve its life. By putting spaces in between the boards, you can improve your decking’s airflow, durability, ease of maintenance, and safety. But the question that follows is, how do you space your decking boards properly? And how can you tell how much space you’ll need to put in between the decking boards?

leave gap between composite decking

How to Space Your Decking Boards Properly


There are two types of spacing for your composite decking boards, namely side-to-side spacing and end-to-end spacing. For side-to-side, you will need to put anywhere from 1/8 inches (3 mm) to 5/16 inches (8 mm). As for the end-to-end spacing, you need to have 1/32 inches to 3/16 inches.

Of course, not all composite decking boards are equal. Because of this, you will need to put consideration on how you’ll space them, including how big the gaps between the decking boards will be. One of the things that you should consider is how much will they expand and shrink.

For instance, dark colours such as grey composite decking boards absorb more heat. When it comes to thermal expansion, they can increase in size faster than lighter-coloured ones. Depending on the brand you’ll be using, some may be more susceptible to expansion than others.

Lastly, when you are installing composite decking, you may need to consult with the boards’ manufacturers. They can give you clear and concise instructions on the building process, including how much gap you will have to put in between the decking boards. Some installation guides may not even require you to put spaces, especially considering how excellent composite decking materials are.

In any case, placing between composite decking boards can either make or break your decking. So you must remember to follow any instructions on how to do them properly.

Tags: gaps between decking

Leave a Comment

Shopping Cart