HOW THE AGGREGATE INDUSTRY BUYS AND SELLS MATERIAL
In the aggregate and landscape materials industry, products are typically sold by either weight or volume. When you purchase by volume, you're buying material measured in cubic yards or cubic feet. Buying by weight, on the other hand, means you're paying a set price per pound or per ton, with the amount determined using a certified scale. These scales are closely regulated by the Weights & Measures agency to ensure accurate measurements, so you can trust that you're getting exactly what you paid for.
If you're new to buying materials like this, there are a few important tips to keep in mind to make sure you're getting the most for your money. First, always confirm whether you're being charged by weight or volume; it makes a difference in how your load is calculated and priced. Second, know the safe weight limit for your vehicle. It's not uncommon for small pickup trucks or trailers to get overloaded, which can lead to dangerous situations or accidents. Being aware of your load's weight not only protects your vehicle but also ensures safety.
How Do Rock Yards Purchase Material?
Most materials in the aggregate industry are purchased by weight from the originating quarry, with only a few exceptions. Typically, products are delivered to rock yards by a truck and transfer, with a full load weighing around 24 tons, the maximum legal weight for most truck and transfer loads.
When a retail center sells material by volume (such as by the cubic yard), they must first calibrate an average weight per yard for each product. This allows them to convert a 24-ton load into a set number of cubic yards for resale. However, this weight-to-volume ratio can vary significantly depending on moisture content, particularly between wet and dry seasons.
While a cubic yard is always a fixed volume, and a ton always equals 2,000 pounds, the weight of a cubic yard of material, especially bark and porous aggregates, can fluctuate greatly. This makes it challenging for yards to maintain accurate and current calibrations throughout the year.
For example, a 24-ton truckload of bark might convert to about 110 yards in July, when it's dry, but only 80 yards or less in January, when the material is wet and heavy. Similarly, porous materials like lava rock absorb water during rainy conditions or when processed and washed at the quarry. This moisture adds weight. A freshly delivered load of lava rock might initially calculate as 1 yard = 0.75 ton (1,500 lbs), but once it dries out during the summer, that same yard could weigh closer to 0.60 ton (1,200 lbs).
So if you're buying a yard of lava rock in July, you'll receive about 1,200 pounds of material. In January, that same yard might weigh 1,500 to 1,600 pounds due to retained moisture. This principle applies not just to lava rock and bark, but also to road base, decomposed granite, and many other moisture-sensitive aggregate products.
Purchasing material by weight is the most reliable way to ensure you're getting a consistent amount, rain or shine. In fact, buying during the dry season is often the smartest approach, because it takes less weight to make up one yard of material, and your money goes farther.
At PRO Aggregate, we purchase and sell material by weight. Our on-site certified trucking scales allow us to weigh every load of bark, lava rock, and aggregate that comes into our yard. We adjust our pricing seasonally to reflect actual costs, lower in the dry season, higher in the wet season, so we can pass the savings on to our customers whenever possible. When you buy by weight, you always get what you pay for, but if you're trying to convert that weight into volume, remember that it will always vary depending on the moisture content.
How Do Rock Yards Sell Material?
Weight versus Volume.
In the aggregate industry, materials are often sold either by volume (typically measured in cubic yards) or by weight (pounds or tons). When sold by volume, products are loaded using a bucket that's calibrated to hold a specific measurement, such as 1 yard, 3/4 yard, or 1/2 yard. If the bucket is filled level to the top, you're receiving an accurate volume. However, if the bucket is underfilled or inconsistently loaded, the actual volume delivered may fall short. When buying by volume, accuracy depends entirely on the loader and the consistency of each bucket.
At PRO Aggregate, we take the guesswork out of the equation. We sell almost all of our products by weight. Each sale is measured using a certified scale, and you're charged based on the exact weight of your load, no estimation, no variation. This eliminates the potential for loader error and ensures you're getting exactly what you paid for, every time. Certified weights and scale tags are provided with each sale to verify quantity.
How much can my vehicle hold?
Safety should always come first when purchasing bulk materials. Overloading your vehicle or trailer can lead to serious issues on the road, including impaired steering, reduced braking ability, and increased risk of accidents. To avoid these problems, it's important to know the maximum weight capacity of your vehicle or trailer before loading.
Before making a purchase, ask the yard staff for the weight per yard of the material you're buying. Different products, especially those that retain moisture like bark or gravel, can vary significantly in weight. Knowing the weight ahead of time helps ensure you stay within your vehicle's safe load limit.
Stay safe, drive smart - and remember: buy when it's dry to get the most material for your money.
General Rules of Thumb
A half-ton pickup can typically carry about 1,000 lbs (or half a ton). A 3/4-ton or 1-ton pickup can handle more weight, but it's important to always refer to your vehicle's owner manual for specific safety guidelines and the maximum cargo load your vehicle can safely carry.
When it comes to material coverage, one cubic yard will cover approximately 120 to 150 square feet at a 2-inch depth, depending on the type of material. Larger products, like 2"-3" cobble or medium bark, will provide less coverage than finer materials.
To better visualize a cubic yard, it's a cube measuring 3 feet long by 3 feet wide by 3 feet high. If you were to spread that volume out evenly, it would cover an area of about 10 feet by 12 feet at 2 inches thick.
One cubic yard is also equal to 27 cubic feet, and since one cubic foot holds roughly 7.5 gallons, that means a cubic yard equals 202.5 gallons. If you use 5-gallon buckets, it would take about 40.5 buckets to equal one cubic yard. This is a great way to picture how much a cubic yard really is, and it can also help when comparing bulk vs. bagged material pricing.
Looking for more tips and tricks for your next landscape project? Check out our other blog posts for insight and guides.