Most soils work great with Perma-Zyme, and they each work a little differently based on their composition. While we offer evaluations to help customers see how specific soil reacts to Perma-Zyme, they are not needed for every project. Our application experts can walk you through applications for your project and help determine if an evaluation is necessary.
In this blog, we’ll take you behind-the-scenes to show you how we evaluate soil.
Our soil evaluations consist of three trials:
A sieve analysis checks the soil’s gradation—in other words, what percent of the soil’s grains are what size. Every soil type has different sized grains, so this analysis tells us what types (and how much of them) you have. With that information, we can better predict how the soil will work with Perma-Zyme.
We use five sieves, which are round metal pans with mesh bottoms. Each sieve has different sized openings in the mesh. Our lab techs stack them from largest to smallest mesh in a machine called a sieve shaker. On the bottom of the stack, they place a collector pan with a solid bottom.
Next, they add soil to the top sieve. The sieve shaker vibrates vigorously, so smaller soil grains fall onto the lower sieves. Fine soil passes through all the sieves and into the collector pan. By weighing the soil that each sieve catches, we can identify what percentage of the soil is what size.
Coarse material like gravel or sand makes Perma-Zyme treated soil strong enough to support traffic’s weight. Usually, soil needs at least 20% coarse material to achieve adequate strength.
We also look for fine matter, which is silt or clay. These soils have tiny grains that fill gaps between larger particles to prevent water or air pockets that could weaken your project. We especially like to find clay in the soil because it reacts well with Perma-Zyme and binds tightly together, whereas silt struggles to bind.
Both silt and clay can pass through the smallest sieve we use, the #200. So, while the sieve analysis tells us that the soil contains fine matter, it doesn’t tell us which kind. To figure that out, we run an Atterberg limits test.
The Atterberg limits test checks fine soil’s plasticity, which is its ability to retain water. Soil must contain the right amount of water (aka optimum moisture) to compact well. Since Perma-Zyme needs good compaction to create strong surfaces, we need to know how much water soil can gain or lose before it becomes too wet or too dry to compact. This range of moisture is the plasticity index (PI).
First, we wet the soil until its consistency resembles peanut butter. Then, we place the mixture into a cup on an Atterberg testing device. The device strikes the cup until the soil collapses. When it does, the soil has reached its liquid limit—when it’s too wet to compact.
Next, we spread a moist soil sample onto a glass plate. We then roll the soil into a ribbon three millimeters thick. Plastic soil can take this shape. But when the soil is too dry, it reaches its plastic limit and breaks.
Finally, we calculate the soil’s PI using this equation: Plastic Limit - Liquid Limit = PI.
Silt and clay have different PIs. A higher PI indicates more clay, while a lower PI indicates more silt. We generally look for a PI of 7 to 15 because that’s when soil contains enough clay to compact thoroughly, yet not so much as to become weak or crumbly.
The best way to know how a soil works with Perma-Zyme is to try it! We treating samples of soil in our lab to ensure with the best results. Additionally, some minerals that work well with Perma-Zyme—like limestone and decomposed granite—won’t show up on a sieve analysis or Atterberg limits test. The Perma-Zyme treatment lets us know they’re present in a particular soil sample.
This is the simplest part of our soil evaluation. We mix a handful of soil with Perma-Zyme and water until it reaches optimum moisture. Then, we shape it to resemble a hockey puck and let it dry. Once it does, we try to break the puck to test its strength.
The puck should be extremely hard. And it should not be easy to break—although our lab crew has fun trying! Soil that survives our break tests in the lab should achieve sufficient strength on the job site, too.
Great question! Most soils work well with Perma-Zyme. They have plenty of coarse material, a good PI, and other minerals to bind them together. But sometimes the tests fail. If that happens, it’s okay! Perma-Zyme can still work. The soil will just need some amendments.
For example, rocky soil may not react to the enzymes in Perma-Zyme, so clay can be imported that will. Or if a soil’s plasticity is too high (indicating a weak soil with too much clay), gravel can be added for strength.
A Substrata rep can help walk through what amendments are, if they are necessary for your project, and what the cost vs savings would be for a project that requires them.
Only U.S. commercial and government customers are eligible. Due to U.S. importation laws, international customers cannot ship soil to our lab here in Nevada, and homeowners are not eligible for a full evaluation.
Make sure to discuss your needs with our application experts first as soil evaluations are not necessary for most projects.
You can contact us and ask for an at-home soil evaluation kit if you're unsure about application. We’ll send you a free, simple tool you can use to check your soil on your own. That way, you’ll have a better idea how it will react with Perma-Zyme. And we’ll still be here to discuss your results and answer any questions you may have.
Our application experts are ready to discuss the specifics of your project and provide tips for a successful Perma-Zyme application. They can help guide you toward any amendments and determining if a full evaluation is needed for your specific project. If you have any additional questions, we are always happy to answer them.