Frequently Asked Questions
Why is construction lumber graded? Who uses this information?
Lumber is graded to ensure that it consistently meets certain strength standards. Architects and engineers design load-bearing structures based on the characteristics of a wood's grade and species, in accordance with federal and local building codes. Grading each piece of lumber makes it easier for builders to select the appropriate strength lumber for a job.
How is construction lumber graded?
Lumber is graded at the lumber mill using federal government standards. These standards were created through exhaustive testing of lumber species, size and every type of defect. As a result, when lumber is graded, you can be sure that its properties are the same as those of all the other pieces of lumber with that grade.
What are defects, and how do they affect grade?
Defects are important grading criteria. Too many defects can weaken the lumber and lower the grade. Here are some of the most common defects.
Wane — The area along the edge of the lumber where wood is missing or where bark is present. Small amounts of wane don't actually weaken the wood, but they do make the wood less attractive.
Splits — Lengthwise separations running completely through the wood. Splits definitely weaken the lumber.
Checks — Separations along the length of the wood. Like splits, checks weaken the lumber.
Crook — A lengthwise curvature of the wood along its narrow edge, which makes it less suitable for structures.
Bow — A lengthwise curvature of the wood along its wide edge. Because the lumber is not square, it's less suitable for structures and more difficult to apply.
Cup — A curvature along the width of the wood, so the piece isn't flat, but arced. As with bowed lumber, cupped lumber is not square - it's less suitable for structural use, and more difficult to apply.
Wood's biggest enemy is moisture and moisture change. Moisture change can causes all the defects listed above, except for wane. To protect against moisture and corresponding defects, wood must be rotated and culled. Sales associates at The Home Depot store are trained on rotation and these defects, and they cull any defective lumber daily so you always get quality lumber. They also flat stack lumber to minimize future culling.
What is a grade stamp, and how do I read it?
Once the grading process is complete, the wood is stamped. All states require structural lumber to be stamped, and building officials check for appropriate stamps on lumber at every jobsite.
Not all lumber is stamped, however. Typically, nonstructural appearance-grade boards (hardwoods, for example) are not stamped. A few states require grade stamps on all lumber, including nonstructural lumber.
A grade stamp includes:
Mill number — Identifies the mill that produced the product. Each mill has its own number, which helps in tracing the source of the wood, if necessary.
Grade designation — Indicates the grade of the wood, allowing buyers to select the correct grade for the job. The grading association that created the standard for mills in a particular region is also identified.
Species — Indicates the type of tree used to make the lumber.
Surfacing technique — Indicates how the wood was finished (e.g., rough sawn or planed; one face rough and the other face smooth; a pattern).
Condition of seasoning — Indicates the moisture content of the wood at the time of surfacing and whether or not the wood has been kiln dried. MC-15 indicates a maximum moisture content of 15%, KD-DRY and S-DRY (surfaced) a max of 19%, and S-GRN over 19%.
Why are different species of lumber available in different parts of the country?
Different species of lumber respond differently to such location-specific factors as weather, earthquakes, hurricanes, moisture changes, insects, stress, snow loads and so on. Local building codes specify which lumber species and grades are appropriate for a particular area. The Home Depot stocks lumber that is species specific to various regions, usually species that pros have successfully used in the area for generations.
What's the difference between nominal and actual size?
There is a difference between the labeled, or nominal, size and the actual size. For example, a nominal 2"x4" is actually 1 1/2" by 3 1/2" inches.
Lumber mills start with wet wood. Many mills dry the wood, causing it to shrink slightly. Then they surface each piece, resulting in a finished product whose actual size is smaller than the original, nominal size. Over the years, grading rules have accepted dry and surfaced wood as the actual size.
Why are select grade boards so expensive?
Select grade boards usually have fewer defects, smaller and fewer knots, better surfacing and an overall higher quality. There is a limited supply of clear fiber available (it represents a small percentage of all timber). Clear fiber usually comes from older trees, or trees that are pruned as they grow. Pruning is not a common practice, but when used, it is labor intensive and adds to the cost.
Can I stain pressure-treated lumber right away?
We recommend using the "cup-of-water" test before staining. Take a cup of water and pour it onto the treated lumber in several places. If the water is absorbed and doesn't bead up, the lumber is ready for painting or staining.
I'm concerned about the environment. Are Millstead products environmentally friendly?
Yes. Millstead is committed to protecting the environment. Our lumber comes from sustainable forests. We give preference to certified wood, which means it's been managed and harvested under strict guidelines and monitored by a third party to ensure that sustainable practices are followed. Our suppliers must meet or exceed local laws and regulations pertaining to their operations and the products they manufacture. None of our wood comes from the 10 most vulnerable forest eco-regions as identified by the World Wildlife Fund.
How do I install a fence panel on a sloped landscape?
Pre-assembled fence panels can be installed on a slope using the stair-step method. With this method, the fence panels gradually step up the landscape with all rails level, rather than parallel to the slope.
Using loose pickets and rails, a fence can be assembled and installed parallel to the slope of the landscape.
At what depth should I bury fence posts?
A general rule of thumb is to place 1/3 of the length of the post in the ground. Use a diameter of 10"-12" for all postholes. We also suggest burying all gate posts, end posts and corner posts 6" deeper than the other posts, especially in areas with high wind or extreme weather. Check your local building codes through your city or county government for further details.
Should all posts be set in concrete?
We recommend that all posts be set in concrete in accordance with local conditions and standard building practices. Posts that are not set in concrete will eventually lean due to wind and weather. Check your local building codes through your city or county government for further details.
Are gates available?
Yes. Most gates are available in 36", 42" or 44" widths. You can make custom gates by using loose components or by trimming a fence panel to the proper width.
Should I paint or stain my fence?
We recommend applying a protective finish to the fence once it is installed. This helps minimize the effects of weathering and maximize the life span of your fence.
Do you have spaced picket panels with closer picket spacing?
Custom fence panels are not available, but we do offer loose pickets and rails in most market areas. These components can be used to create your own spaced picket panel with your desired picket spacing. We have a variety of picket styles to choose from.