Spacing trex deck boards install#
Spacing trex deck boards code#

If you’re living in a place with this code, you could be required to uninstall your boards. There are plenty of jurisdictions that follow the International Building Code.Īnd according to code, you will need to leave a minimum of 1/8 in (0.32 cm) gap between your deck boards.

Spacing trex deck boards code#

The first thing you need to consider and check is if your local building code covers deck board spacing. There are a few other factors to consider here.

Here’s a helpful video about types of wood to use for a deck and proper board spacing: If you want to avoid these complications, you might want to consider installing your deck boards during the dry season. This means the boards will go flush during the rest of the humid season, and then once they lose the moisture from the pressure treatment and the additional moisture accumulated during the wet season, they will contract back in the dryer seasons.

If you’re using pressure-treated boards, you might want to leave a smaller gap of about 1/8 in (0.32 cm).This way, the boards will expand over the rest of the humid season and then shrink once the dry seasons arrive, leaving an appropriate gap.

Spacing trex deck boards install#

So if you are using dry, untreated boards, you will have to install them with a slight gap of about 1/4 in (0.64 cm).

But instead, you will have to account for both the expansion during the remainder of the humid season and then the eventual shrinking that the boards will go through during the dryer months. You might think that the process will simply be reversed. If you’re installing deck boards during the humid months, the process can get a bit more complicated. Installing Deck Boards During the Humid Months This way, the boards will shrink enough over time, leaving an appropriate gap. To account for this, you will have to install pressure treated deck boards flush. You must also consider that if your deck boards are pressure treated, they will come with some moisture in them and will eventually shrink down.

A 1/8 in (0.32 cm) gap, on the other hand, won’t be as hazardous as a 1/4 in (0.64 cm) gap.

But the wide gap may also be a safety hazard, as it can lead to tripping.

A 1/4 inch gap is more desirable with respect to other factors such as ventilation, drainage, and debris removal.

So, in this case, you should consider leaving a gap between 1/4 and 1/8 in (0.64 and 0.32 cm) between the boards. If you’re installing deck boards during the dryer months, you will have to consider that the boards will soak in moisture in the more humid months and, as a result, expand. Installing Deck Boards During the Dryer Months But it depends on what season you install the boards in. The best way to deal with the shrinking and expanding of deck boards is to leave proper spacing. But what if you live in a place with wild swings in humidity? What Do I Do About the Shrinking and Expanding of Deck Boards? If you live in a place where the humidity stays pretty much constant throughout the year, you won’t have to worry too much about your deck boards shrinking or expanding. Of course, this seasonal expansion and contraction of the boards depend on where you live. And during the dryer months of winter, the boards will once again contract as they lose their moisture. During the more humid months of summer, the wood fibers in the boards will soak in more moisture, leading them to expand. This factor is further complicated by the fact that deck boards are installed outdoors and are subject to the changing seasons.

And when they dry out, the fibers contract, making the deck boards shrink.

When these fibers hold moisture, they tend to expand, making the boards bigger.

And these fibers have the ability to hold on to moisture. The simple science is that wood is made up of fibers. There are many factors that determine the shrinking and expansion of deck boards. Due to the fluctuations in the humidity in the air, deck boards will continue to cycle between expansion and shrinking. Since deck boards are mostly installed outdoors, over time, enough exposure to the sun will dry them up and lead them to shrink a little.īut it doesn’t just end there. When wet, the fiber in the woods holds moisture and, as a result, expands. Most deck boards are pressure treated, which means they will be somewhat wet when they’re new. This is why it is necessary to leave appropriate spacing between them when building a deck.