Introduction of Grade Rod

How do you determine if a piece of wood is structurally sound? For lumber, this is determined by evaluating it on the structural grading system, also known as the grade rod method. This system was developed in Canada, and has since been adopted by the American Lumber Standards (ALS) and American National Standards Institute (ANSI). The grade rod method determines the amount of moisture in the wood, as well as its strength and quality based on a series of physical tests. It will be either high quality (A Grade), or not so great quality (B Grade).

The Complete Guide to Grade Rods

Grading rods come in a variety of lengths and diameters, so you'll need to consider what will work best for your project. For instance, if you're measuring a small area or using a narrow rod, 16 or 18 diameter will give you better accuracy than a larger 22-24 diameter rod.

You'll also want to think about how far out from your survey point you plan on getting measurements; shorter rods are typically easier to use because they minimize measurement errors caused by changes in elevation over longer distances. For example, an L-rod works great for short distance measurements within 10 feet or less while a stadia rod may be better suited to long distance measurements such as property lines that span several hundred feet (or more).

In addition to length and diameter, grade rods come in two different types: rigid and flexible. Both types offer advantages depending on your specific surveying needs, you can find out what each one offers with our guide below.

Common Types of Grade Rods

The most common types of grade rods are Philadelphia level rods, direct reading rods, target rods and direct elevation rods. Although all grades have a general frame in which they function, their differences come down to measuring units and angles.

Philadelphia level rods have a rectangular face (hence the name), whereas Direct Reading Rods look more like a protractor; they vary in graduations and are used to measure out three-dimensional spaces (e.g., indoor volumes). Target Rods feature different colors on each side; they use color-coding systems to indicate points of interest.

The most versatile grade rod is direct elevation rod, since it also gives users measurements relative to planes—vertical or horizontal—as well as degrees for inclines or declines. A Level is mostly used by constructors to establish whether one surface plane is level or parallel with another plane.

Understanding Grade Rods

Grade rods are one of many ways to measure and represent grades on a construction site. They’re usually made of fiberglass, aluminum, steel or plastic, although there are glass-reinforced varieties for added durability.

Grade rods also have different materials depending on whether they’re used for temporary installations or long-term ones. The main thing that sets grade rods apart from other measuring devices is their ability to come in different lengths and thicknesses, depending on your preferences and needs.

In addition to being available in a range of sizes, grade rods come with accessories like extension cables and installation kits that help you adjust them to fit your measurements. You can extend any rod at any time by simply connecting an additional length of rod to it through either its upper end (with universal types) or bottom end (for butt types).

That way, when your project goes out further than anticipated, it won’t throw off your measurements if you can connect some more rod and still get accurate results. Many grade rods come with protective caps that keep any rough edges from damaging surfaces and getting in accidents between uses.