How to install deck boards crown up or down?

By Mark Decking DIY Questions

If you have crowning deck boards, knowing whether to install deck boards crown up or down during a deck installation isn’t as important as ventilation and decking width when building a backyard deck that you want to last for a long time. However, installing deck boards correctly can impact how the deck ages over time and how the deck looks. So crown up or down on deck boards? What is the correct way to install decking boards? Here’s what you need to know about crowning deck boards so you can know how to lay deck boards correctly.

Question: Deck boards crown up or down?

I am building a deck. I have heard that some carpenters install the deck boards with the bark side of the deck board facing up. And I want to build this right. What’s your take on installing deck boards crown up or down?

‣ MyFixitUpLife How to lay deck boards: crown (grain) up or down during deck installation? MyFixitUpLife — Installing deck boards crown up or down

Answer: How to lay deck crowning boards

My take is this: Good question.

There has been conversation about this amongst deck builders for years about this deck installation detail. And the good news is that the answer about the crown up or down is simple. Here’s what you need to know about installing deck boards crown up or down.

What is deck board crowning?
It’s the natural curve of a deck board that follows the rings.
These curves tend to flatten out naturally as the wood dries over time.

How to lay deck boards: Grain direction up or down?

Grain direction and crown (bark side up/pith side up) doesn’t really matter when installing deck boards.

No matter about crowning deck boards, what you want to do is put the best face of the board up during a deck installation. And by best face I mean the nicest face—any wane or bark goes down. I install pressure treated decking and Western Red Cedar decking this way.

It is generally pretty clear which side is the face side, so you won’t have to be flipping boards all day to figure it out, which is nice.

So how do extend the life of the decking?

To really extend the service life of the wood, the science I have read says the key is to keep the underside of the deck well-ventilated and as dry as possible so that the top of the deck board (the face side) and the bottom of the deck board dry at as similar a rate as possible.

Finally, and this may be a personal preference. If it’s in your budget, bump up to a 2×6 deck board. More wood means more wood, both to resist the forces of nature and for the fastener to hold on to.

Check out our detailed “How to Build a Deck” video series

‣ MyFixitUpLife how to build a deck - part 1 - myfixituplife — 1. How to build a deck – part 1

‣ MyFixitUpLife how to build a deck - part 2 - myfixituplife — 1. How to build a deck – part 1

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About the Author

Mark

A licensed contractor, tool expert, wood and outdoor enthusiast, and elite Spartan Race competitor, he writes about home improvement and tools for national magazines and websites, and teaches hands-on clinics for other remodeling professionals. Check out his book, The Carpenter's Notebook.

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