Whenever you receive an order for a deck installation, your customer probably has some pretty lofty expectations. Often, they’ll assume that you’re able to install a deck with little to no gap between the boards, and that once the deck is installed, the boards will stay in place exactly where you fasten them, as if by magic. As a woodworker, you know that this expectation isn’t completely realistic. You have to break it to your inexperienced customer as gently as possible that wood, as an organic product, will always have a tendency to move.
But how do you space your decking to allow for as little noticeable movement as possible? That depends on a number of factors. In the following three-part series of articles, we’ll explore in depth some of the considerations you’ll need to keep in mind when it comes to spacing your decking boards.
Consider the Species of Wood You’re Using
Not all species of wood will tend to move in the same way and at the same rate. Tropical wood species, such as Ipe, Cumaru, Jatoba, and Teak, all tend to be quite stable when it comes to not experiencing much wood movement. Some domestic species tend to be less stable and may move more dramatically over time and throughout the course of a year. This is one of the main reasons why tropical decking is so popular and recommended by experts for decking projects.
If you have a question about the stability of a species of wood and you want to find out how much you can expect it to move, you could consider getting a wood shrinkage calculator app on your phone. There are a number of good woodworking apps out there that include shrinkage calculators, such as those found here. You can type in the species of wood you’re planning on working with as well as the size and cut of your boards. These apps include plenty of helpful general information about the different species as well as how much those species can be expected to move when transported to different locations.
Consider the Location of Your Decking Project
Speaking of locations, the final destination of your decking material is going to make a big difference in how much your wood is going to move. Some areas of the country see lots of precipitation, moisture, and humidity. Other areas tend to be relatively dry and enjoy much lower levels of humidity. The latter conditions are going to be far easier on your decking wood when it comes to how much overall movement you should expect to see in both the short and long term.
If you’re installing a deck in an area with high humidity, such as New Orleans, Jacksonville, Houston, or Seattle, you should expect a higher rate of wood movement than you would in a dry climate such as that of Phoenix, Las Vegas, Salt Lake City, or Denver. Take a look at the average yearly humidity rates and fluctuations of the area where you’re installing the deck and plan accordingly when it comes to spacing your decking boards.
In our next article in this series, we’ll take a look at some more factors that can impact your decking board movement.