Nominal Vs. Net Finished Dimensions – What You Need to Know

If you’re looking to build a deck for the very first time, the first thing you need to know is how much decking to buy. Many people make the mistake of planning their materials list based on what’s known in the lumber world as “nominal dimensions.” 1×4, 1×6, 5/4×4, and 5/4×6. These are the most popular “nominal dimensions” and are the terms we are all used to hearing on TV shows and even in DIY deck building books. However, what you need to know is that “nominal dimensions” refer to a piece of unfinished/rough lumber that has not yet been milled (aka surfaced).

You see, during the milling process, every piece of decking gets smoothed out to remove any raised grains and splinters. This process is called “surfacing” and ensures that the decking you buy is smooth and safe for bare feet. For example, when a piece of rough 1×6 decking is surfaced, the “net finished” or “actual” dimension of the board will be 3/4″x5 1/2″ (see the above picture). Ultimately, knowing just how much decking you’re really going to need will save you time and money.

If you would like a complimentary quote for your next deck remodeling project and need an accurate piece count, call 1-877-232-3915.

Here are some other popular decking sizes and their finished dimensions:

Here’s our popular Advantage Pregrooved 1×6 +Plus ®. Note the extra thickness over 1×6 decking material.
5/4×4 Tongue & Groove is perfect for sunrooms, covered porches, and screened in lanais.
This custom-milled rainscreen siding profile requires no predrilling and reduces water intrusion.
Advantage 1×6 +Plus® is also available as a exterior wood siding option.

1 thought on “Nominal Vs. Net Finished Dimensions – What You Need to Know”

  1. Incorporating eco-friendly materials into deck repairs is a brilliant idea. It’s inspiring to see sustainability being emphasized in home improvement projects. Fantastic job!

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