Deck board spacing matters

The correct spacing between planks for your deck? Handyman Hints has the answer. Handout/Postmedia Network
The correct spacing between planks for your deck? Handyman Hints has the answer. Handout/Postmedia Network

With the framework, railing systems, and stair stringer work completed, we’re now ready to install our treated decking planks.

The big question of course is, what should be the spacing in between the planks? However, and before coming to a spacing decision, let’s first examine the inherent characteristics of lumber, and how that relates to our landscape, and of course the time of year.

Now, does deck board spacing really need to be examined so scientifically? After all, this isn’t exactly the lounge deck off the stern of the Queen Mary, where it would see duty hosting royalty and world dignitaries.

We’re talking about an outdoor living space that’ll see plenty of spilled beer, barbecue sauce, hot dogs getting squished in between the planks, and maybe even the odd Leaf fan.

So, why scrutinize the plank spacing when its future will see such abuse and roughhousing? Because, deck board spacing matters.

Deck board spacing based on a strategy related to real information and atmospheric conditions, will provide years of beautiful, along with less maintenance, outdoor living.

What are the consequences of not following a plan, or disregarding the elements?

Aching lower back, followed by the dependency on medication, wrapping up with the eventual loss of sanity.

Now, the medication dependency and sanity issues are most probably worst case scenario outcomes, but I tell ya, the aching back due to always having to care for your decking planks, should the spacing be off, is a guarantee.

What are the characteristics of wood? Wood will shrink and expand during seasonal fluctuations in both temperature and humidity levels.

As a result, decking planks (which are normally 5-1/2 inches in diameter) will shrink down to about 5-1/4 inches during the sub-zero months, and may expand to about 5-5/8 inches wide during the summer.

With this fact in mind, we know we can space our boards a little closer during a hot, summer install, because the planks are generally at their widest.

Conversely, if the install was to take place during the early spring, or late fall, the decking planks should be spaced a little further apart, which would allow for future expansion.

What exactly does “a little closer” or “a little further apart” mean in terms of measurement?

I like to use the common nail strategy, relying on the width of a 2 inch (summer), 3 inch (spring/fall), or 4 inch (sub-zero), size of nail to determine board spacing at specific times of the year. The longer the nail, the thicker the shaft, and therefore the wider the spacing.

Generally, decking planks will tend to shrink on the width, and not so much on the length. However, don’t make the mistake of treating your decking planks like they were hardwood flooring.

With the knowledge that the planks are most likely to shrink a little, rather than further expand, during a summer installation, you may get the urge to place the decking planks tightly together. Avoid this urge.

Yes, the planks will shrink slightly, leaving a small gap in between each board that will initially look quite attractive.

However, once the dust, leaf matter, and helicopter seeds (compliments of our local maple trees) descend into this perfectly sized crack, the space between each board will fill up with debris faster than you say “hey, did you hear PK Subban’s latest country and western single?”

When that happens, you’ll be forced to scratch out the gunk with a hook bladed knife.

Unfortunately, most people tend to pass on the ensuing knee and back pain of that process, and instead turn to a pressure washer.

A pressure washer will be very effective in removing the debris, as it will effectively saturate your deck with water, and effectively remove the stained or clear coat finish.

When the wood is finally settled, what you want is about a ¼ inch space between planks.

This will allow for good drainage of rain and snow melt, and easier cleaning with nothing more powerful than a broom and garden hose.

Good building.

As published by the Standard-Freeholder
Handyman's Hints Standard-Freeholder Cornwall Ontario by Chris Emard

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