Starting a new woodworking project can be confusing when you’re faced with the different sizes and terminology used to describe lumber. From “nominal” sizes to “board feet”, it’s like learning a whole new language! But understanding lumber dimensions is key for buying enough material and cutting it accurately.
This article will clearly explain the different categories and measurements of lumber so even beginners can enter the store prepared and confident. With the right know-how, you’ll be ready to turn raw wood into beautiful, functional projects. Let’s get started!
| Takeaway | Summary |
|---|---|
| Hardwood vs Softwood | Hardwood comes from deciduous trees like oak and maple; tends to be dense and strong. Softwood comes from evergreens like pine and cedar; typically lightweight. |
| Nominal vs Actual Size | Nominal sizes describe naming conventions like “2×4”. Actual sizes are typically 1/2″ smaller to account for milling. |
| Standard Lengths | Common lengths range from 8′ to 16′ in 2′ increments. |
| Specialty Cuts | Different terms describe thickness: Board (<2”), Plank (2”-4”), Beam (>4”). |
| Measuring Lumber | Use tools like tape measure, folding rule, calipers, and micrometer. Mark cuts clearly. |
| Buying Lumber Tips | Check grade stamps, calculate board feet, buy 10-20% extra, store properly to avoid warping. |
Common Types of Lumber
Before diving into dimensions, it’s helpful to understand a bit about lumber categories:
Hardwood vs. Softwood
Hardwood comes from deciduous trees like oak, maple, cherry that seasonally lose their leaves. It tends to be dense, strong, and more expensive.
Softwood comes from coniferous evergreen trees like pine, cedar, and fir. It is typically lightweight and less expensive than hardwood.
Image caption: Oak and maple hardwood boards ready for projects.
Natural vs. Engineered Wood
Natural wood like pine boards or oak planks are cut directly from the log into standard sizes.
Engineered wood like plywood, OSB, and MDF are manufactured by bonding wood materials, fibers, veneers etc. with adhesives into sheet sizes.
So those are the main differences – now let’s move on to understanding lumber dimensions.
Standard Lumber Dimensions
Lumber dimensions can be confusing because there are nominal sizes and actual sizes.
What’s the Difference?
Nominal sizes describe commercial naming conventions – what you’ll see written on the tag when you go to buy lumber. For example “2×4” or “4×4’.
Actual sizes reflect the real measured dimensions of the cut lumber after drying and milling. Actual sizes are always a bit smaller since the wood is smoothed from raw timber into building material. Typically actual thickness and width are 1⁄2” smaller than nominal size
For example, a “4×4” is actually cut to measure 3 1⁄2″ x 3 1⁄2”.
A chart showing the difference between nominal and actual lumber sizes.
Knowing the actual size helps enormously when planning woodworking projects!
Standard Lengths
Lumber also comes in standard length increments, usually ranging from 8’ to 16’ lengths:
- 8’
- 10’
- 12’
- 14’
- 16′
There are bigger sizes used for heavy timber construction, and smaller specialty pieces as needed. This covers most home building and DIY work.
Buying Specialty Cuts
Beyond basic width/thickness, there are some special lumber designations:
- Board – Less than 2″ thick
- Plank – 2″ to 4″ thickness
- Beam – Greater than 4″ thickness and wider sizes like 4”x12”
- Stud – Narrow wood strips 2×4 and 2×6 commonly used to frame walls and partitions
This vocabulary will help communicate with your lumber supplier when buying speciality material.
Now that we understand the theory, let’s switch gears to everyday practicalities…
Measuring and Marking Lumber
When working with lumber, good measurement technique is critical for accuracy:
Use a tape measure for lengths and distances. Hook it over the end of the board and pull straight and taut along the edge.
A folding rule or calipers can measure internal dimensions like grooves, mortises etc.
For thickness, use a dial caliper or micrometer for precision.
Mark cuts clearly with pencil or lumber crayon before bringing the saw!
Errors can compound, throwing entire projects off. Investing in reliable tools and diligent technique makes all the difference.
Accurately measuring a piece of lumber before cutting to length. Use a folding rule pushed flush to the edge.
Dimension matters – so measure twice, cut once as the old carpenters’ saying goes!
Purchasing the Right Wood
When buying lumber, there are a few quick checks that’ll set your project up for success:
Check Grade Stamps
Most milled lumber is stamped with a grading code that tells you the quality. Higher “Select” grades have fewer knots or irregularities. Understand the grades so you buy lumber suitable for purpose.
Calculate Board Feet
“Board feet” measures usable wood quantity. Calculating board feet helps ensure you purchase enough material. There are online calculators that make it easy.
Buy 10-20% Extra
It never hurts to buy a bit extra wood for planning, testing finishes, inevitable defects or cutting errors. Unique grains and textures might lead you to set aside nicer cuttings for special small projects too.
Store Lumber Properly
Keep wood stored flat, evenly supported, and covered. Changes in humidity or dampness can cause warping, cracking or cupping if the grain absorbs water unevenly. Careful storage preserves quality.
Conclusion
I hope this lumber primer clears up some of most common terminology and processes for working with wood material. While it may seem daunting at first, the measuring systems and techniques make more sense once you actually get hands-on practice buying some boards and cutting joinery. The most important things are using sharp, well-calibrated tools and always taking the time to measure carefully. Understanding these fundamental concepts will build confidence and set you up to craft awesome projects!
For more tips check out our Top Woodworking Tips or browse DIY plans in our woodworking projects section. Just take it step-by-step and you’ll be creating works of art in no time!
Frequently Asked Questions
Why is there a size difference between nominal and actual dimensions?
The nominal sizes date back over 100 years to simplify communicating lumber dimensions. Today the actual sizes account for drying, planning, smoothing from rough-cut timber into standard usable lumber.
What is the standard length for dimensional lumbers?
The most common lengths are increments of 2 feet between 8’ and 16’. Special order lengths are available but the bulk of everyday construction lumber falls into this range.
How long can I store lumber before it starts to warp?
Stored properly, lumber can sit for 2 years without issues. Keep it flat, evenly supported, and away from big humidity or temperature swings. Covering the stack can also prevent uneven drying.
What does the grade stamp on a piece of lumber mean?
The stamps or tags indicate the mill, species, moisture content, and most importantly – the quality grade. Standards agencies like NHLA, NELMA, and NLGA have grading rules to standardize assessments across different mills.
Is hardwood always better than softwood for DIY projects?
Not necessarily. Hardness and workability varies widely across wood species. Finishes and intended use might make a softer wood preferable. Alder takes stain beautifully for example. Talk to your lumber supplier about characteristics of each type.
How do I calculate how much lumber I need for a project?
Use a board foot calculator to determine total volume of wood. Calculate 10-20% extra to allow for defects and cutting. Remember actual thickness/widths, not nominal sizes. Buy from a store that allows returns to hedge on the safe side.
External Resources
- National Hardwood Lumber Association lumber grade rules and reference guides for different wood species.
- Home Depot Guide to Lumber Grading – great visual reference images for different quality grades and grain characteristics.
- Watch on YouTube: Quick demo of actually measuring lumber dimensions with a tape measure and folding rule. Shows techniques in action.
We’d love to hear about your adventures working with lumber as you get started crafting! Share any lessons learned or burning questions in the comments. Let’s build this community knowledge together. Happy woodworking!
Below are three external links that could be relevant to this article:
- National Hardwood Lumber Association lumber grade rules and reference guides for different wood species.
- Home Depot Guide to Lumber Grading – great visual reference images for different quality grades and grain characteristics.
Watch on YouTube: Quick demo of actually measuring lumber dimensions with a tape measure and folding rule. Shows techniques in action.