This blog is to help explain the differences between nominal and true sized lumber. Most of our bracket plates won't be affected by the size difference, but brackets like Joist Holders or Beam Brackets will be affected. We highly recommend you ready this blog if you are not familiar with the difference between the two.
Nominal Wood
Let's start with nominal wood posts. Do you ever wonder why, when you go to a hardware store to pick out a 2x4 or a 2x6 and you get home and measure it, the numbers don’t add up? The simple or not so simple answer is it reflects the “Nominal” measurement. So, what does that mean? Well at one time that piece of wood you purchased was cut to the specific size on its label by the lumberyard, but then it was dried, and a certain amount milled off (planned) and smoothed on all sides before it was ready to be sold to you. When you purchase nominal wood, its actual size is typically a ½ inch smaller than what it's labeled due to the finishing process. Meaning that nominal 2x4 post you purchased is actually 1-½ x 3-½. If you want to know the history behind why the numbers don’t add up, you can look up the “Bureau of Standards in the wood-usingindustry”. The industry standards for lumber were first implemented after World War 1 and last updated in 1964. Follow the link to that original manual for those who desire to dig deeper, there is some interesting history.
Now, let’s dive into some of the reasons why things can get a bit more complicated. Sometimes, if you purchase a hardwood 2x4 or a roughcut 2x4, it may be larger than 3-1/2 inches and even a true 2x4. There are several factors that contribute to this phenomenon, such as the drying process, the milling process, and the natural characteristics of the wood itself. In the following sections, we will explore some of these reasons in more detail.
True or Actual Size Wood (Rough Cut and Hardwoods)
Rough Cut wood is often made from hardwood species, but not always. For instance, cedar, is a softwood and is often roughcut. Rough cut is when lumber has been cut to a specific size but has not been smoothed out during the milling process and therefore has a rough surface with saw marks. Rough Cut Wood may dry up or shrink a little after it has been cut, anywhere from 1/8” to 1/4” smaller, but because it hasn’t been planned to smooth out the rough spots, it is typically closer to an actual or true size post. So, if you are using rough cut wood make sure you measure to make sure the bracket you order will fit.
Hardwood can sometimes be a mystery in regard to the size you will end up with to the average non-builder, because it is generally not sold in standard dimensions. Instead, it is sold by the board foot. Hardwood lumber is also not always finished (surfaced) on all sides. So, a board that is only surfaced on one side is going to be larger than a board surfaced on two sides. In addition, where you purchase (big box store, lumberyard or sawmill) matters as the quality of wood and size can vary widely. So just like when using rough cut wood post, make sure you measure to make sure the bracket you order will fit.
Pressure Treated Wood
The industry standard for pine pressure treated 2x4 is 1-1/2” x 3-1/2”. Pressure treated lumber is chemically treated to withstand rotting and insect attacks that happen by leaving wood open to the elements. If you are picking up your post from a lumberyard, they may have stored their pressure treated wood outside (to preserve space for non-pressure treated wood) which means they might have moisture in them when you purchase them, causing them to be slightly over 3-1/2”. With a few dry sunny warm days, most will dry out and shrink back up. This is not always guaranteed as with any contracting or swelling it can leave the wood permanently warped. So, some slight sanding may be needed for our nominal brackets to fit.
Let's face it—that is a lot of information to take in, but we want you to understand why when you purchase one of our brackets they might not fit as expected. Most of our brackets are designed for the industry standard for nominal wood posts, unless specifically noted at "true sized". Therefore, we urge our customers to measure their lumber to ensure they are ordering the correct size bracket.
JOIST HANGERS
JOIST HANGERS
Add some support to your floor/ceiling joists with these heavy-duty joist hangers.
TRUSS SETS
TRUSS SETS
Outfit and support your exposed trusses with these full sets of brackets. We made it simple!
GABLE PLATES
GABLE PLATES
It can be hard to find a gable bracket that fits your needs. Instead, customize one with our unique process!
Industrial Style
Industrial Style
Our most popular style of bracket. Adds a very "modern-industrial" look to any project while adding a whole lot of support!
DECORATIVE BRACKETS
DECORATIVE BRACKETS
For a unique touch, add some of our decorative brackets to the mix!
BEAM BRACKETS
BEAM BRACKETS
Rest easy with our beam brackets supporting your lumber connections!
Hardware
Hardware
You are going to need hardware! Get them color matched to your brackets! (or not... we won't judge)