13 Jul Lumber Quality in Home Building
Goertzen Homes is well known for building good, sound and long-lasting homes. As you walk through our homes, you will notice the features and quality workmanship that make our homes unique. Our attention to detail starts with the quality of wood used in the framing process. The lumber we use to frame our houses is a step above what is normally used in home building, and it makes for a more stable house, with straighter and stronger walls.
There are four basic grades of structural framing lumber designed for light construction such as house building. The following scale provides a metric to determine the quality and strength of the wood based on the existence, placement and size of knots and defects. Each stick is given a percentage “clear wood” grade – those with fewer knots receive a higher percentage clear wood status for strength and appearance.
- Select Structural. This lumber is largely clear of knots. The knots that do exist are small and tight. It is the strongest of the four grades, high in quality, limited in characteristics that affect strength or stiffness. It is recommended for uses where high strength, stiffness and good appearance are desired.
- No. 1. Small, tight knots up to 1-1/2” are allowed. Loose knots can only be 1” wide and can only appear once every 3 feet.
- No. 2. This wood features well-spaced knots of any quality up to 2” wide. It can have knotholes that are 1-1/4” wide, spaced every 2 feet.
- No. 3. Knots of any quality can be up to 2-1/2” wide. Knotholes are allowed every 1-3/4” foot.
Select Structural grade is at least 80 percent clear wood, No. 1 is 75 percent, No. 2 is 66 percent and No. 3 is at least 50 percent clear wood. There are lower grades of lumber not suitable for home-building. The following picture is a good example of the appearance differences.
Lumber Species and Density (Weight)
Another way to look at the quality of lumber is by weight. SPF (Spruce, Pine, Fir) dimensional lumber is approximately 25 to 28 lbs/cu.ft. and Hem-Fir Select Structural weighs in at 29 to 31 lbs/cu.ft. The combination of Spruce, Pine, and Fir (SPF) is lower in tensile strength, while Hem-Fir varieties tend to be denser, thus stronger.
The “S” in SPF stands for Black, Red, White, or Engelmann Spruce. The “P” means Jack or Lodgepole Pine. The “F” is either Balsam Fir or Alpine Fir, depending on whether it was logged in Eastern or Western regions. This species of fir is a lighter and more broad-grained lumber than Doug or Hem Fir, resulting in a lower quality wood grade. There is another SPF grade with an “s” distinction – SPFs. This type is grown in the South and is not as strong as Northern species. Included in this group are Norway Pine and Sitka Spruce – two species not found in the Northern grouping.
Wood grain is an indicator of strength and stability and varies among different species of lumber. If grain lines are straight and close together, wood is heavier – strong and stable. Hem Fir or Doug Fir varieties have tight, close grain lines. Pine has broad grain lines that wander. The soft wood between the grain lines shrinks and expands, making the wood cup or twist. Pine features significant soft grain – it is a softer wood species. Hem Fir or Doug Fir is much denser, harder and stronger, more stable, and is less prone to warping or twisting.
Lumber is graded according to the rules of the National Lumber Grades Authority (NLGA). Agencies inspect the products from all mills regularly to ensure that the grades are accurate. All lumber can have natural defects, such as a large knot or a long split, that can reduce its overall strength. However, not all defects are obvious. Therefore, each stick of lumber coming out of a sawmill is appraised by trained inspectors and given a grade stamp.
We Feature the Best
At Goertzen Homes, we use Select Structural Hem Fir lumber and wall studs are a premium-grade Doug Fir. Using a higher-grade lumber ensures less time is spent sorting through lumber, resulting in a more efficient building process. It also generates less material waste, as the lumber is usually straighter with less warping. Our homes are heavier, as evidenced by weight determined by professional home moving companies. Overall, the choice to use higher-grade lumber produces a strong, solid home that will last a lifetime. The following two pics are what we use in our house framing (Select Structural Hem Fir):
The next two photos are what we use for studs
The quality of lumber we use is just one of many reasons you should place your confidence in us to build your next home. Come see us today and walk through our model homes. We can design and build a home with a floor plan you will love, can raise your family in and can enjoy into your sunset years.