Different soil stabilizers work best in different types of soils, and Perma-Zyme is no exception. Soils that are most compatible with Perma-Zyme have 15-80% clay content and varied particle sizes. 

So, what if your soil doesn’t fit the bill? Don’t worry! Incompatible soil is not the end of the world. Typically, you can make simple, natural soil amendments with limestone, decomposed granite, or aggregate to produce excellent results when using Perma-Zyme. 

In this article, we’ll walk you through:

  • What types of soil are (and aren’t) compatible with Perma-Zyme
  • How to tell whether your soil is compatible
  • Why you should make soil amendments
  • Which soil amendments to use for your project

The Most Perma-Zyme Compatible Soils

There are four main types of soil: gravel, sand, silt, and clay. Most project sites contain a mix of two or more soil types; this mixture is called loam. Generally, clay-based soils or those that contain tiny fragments of limestone rock are the most compatible with Perma-Zyme. We'll talk more about limestone-based soils in a minute; for now, let's focus on clay. 

Why Clay Works Well

Clay-based soils work well with Perma-Zyme because they contain lots of organic matter. This organic matter consists of negatively charged particles called anions. Meanwhile, the enzymes in Perma-Zyme contain positively charged particles called cations. When you mix the two, they create a chemical reaction that permanently bonds the clay particles together into a hard, concrete-like surface. 

How Much Clay Your Soil Needs

Compatible soils need at least 15% clay to work their best with Perma-Zyme. However, there’s such a thing as having too much clay in your soil. Ideal soils contain less than 80% clay because the soil needs a variety of particle sizes to give it good shear strength. Clay has the smallest particles of any soil type, so it’s dense but not very structurally sound. If your soil contains at least 20% larger particles like sand and gravel, the clay will bond around those particles and make the treated area stronger.

Soil’s Plasticity 

Another measure of soil’s compatibility is its plasticity. Plasticity refers to how easily you can shape soil. When soil is in its plastic state, you can stretch, mold, and compact it. Compaction is the key to a successful Perma-Zyme application because it pushes the clay particles as close together as possible to create a strong, smooth surface. So, for proper compaction, you’ll need soil with plenty of plasticity. 

Geotechnical engineers accurately calculate the soil’s plasticity using an Atterberg test. Soil that scores greater than seven on the Atterberg is Perma-Zyme compatible. However, you can also estimate soil’s plasticity by hand (more on that soon).

If you’ve ever been around clay soil, you know it’s very plastic. When it’s wet, it looks and feels like Play-Doh, and you can easily roll it into a ball. So, checking soil’s plasticity is another way of confirming that it has the right clay content and physical properties to work with Perma-Zyme. 

The Least Perma-Zyme Compatible Soils

Soils that are primarily made up of gravel, sand, or silt aren’t naturally compatible with Perma-Zyme, and neither are soils that contain mica. Let’s dig into why that is. 

Gravel and Sand

Gravelly and sandy soils are both incompatible with Perma-Zyme because they lack sufficient negatively charged matter. Some rocks and sand particles even have a positive charge instead of a negative one. So, the enzymes in Perma-Zyme can’t chemically react with pure gravel, pure sand, sandy loams, or gravelly loams.


Many people are surprised to learn that silt and silty loams are incompatible with Perma-Zyme. Silty soils are often associated with rivers and agriculture, so it would seem as if they should have enough organic content to work with Perma-Zyme.

However, silt has high nutrient content—not high organic content. Like gravel and sand, silt originates from tiny, inorganic rock particles. Those particles have a slight negative charge, but they also have limited surface area compared to clay. Because they're larger, more of the negative charge is "hidden" inside the particles, where the enzymes can't reach it. So, its negative charge isn't strong enough to react chemically with Perma-Zyme.

On top of that, silt is very dense and hard to compact. Since compaction is key to a successful Perma-Zyme application, silt is ineffective.


Technically, mica isn't soil. It’s a group of minerals that contain a mix of silica and oxygen molecules. Mica can look pearly, sparkly, or glassy. You might be surprised to know that you use it everyday; there's mica in everything from the drywall in your home to the tires on your car. 

Mica has a net negative charge, so you’d think it would work great with Perma-Zyme. Unfortunately, it’s the opposite: mica renders soil incompatible with Perma-Zyme. Here are some possible reasons: 

  • Mica may make the soil too flaky. Silica particles are shaped like flat plates. This mineral structure can interfere with chemical bonds—such as the bonds Perma-Zyme attempts to make with clay particles in the soil. 
  • The pH balance could be off. Enzymes work best when the soil’s pH stays within a particular range, and each type of enzyme has a slightly different optimal pH. Since there are multiple enzymes in Perma-Zyme, some types of mica may have a pH that falls outside the ideal range for one or more of them.
  • Mica doesn’t retain water well. With low water retention, it’s hard to get the soil to maintain its optimum moisture content during construction, making it harder to fully compact the Perma-Zyme treated soil for an effective application.
  • Mica contains other minerals, like potassium and aluminum. Some of these could inhibit the enzymes from bonding the soil effectively.

If there’s mica in your soil, there’s a chance that—even with soil amendments—it may prevent Perma-Zyme from working effectively. That’s why it’s so crucial to find out if your soil is compatible and talk to our soil stabilization experts to understand how Perma-Zyme will work for your specific situation. Next, we’ll show you how to find out if your soil is compatible. 

How Do I Know If My Soil Is Compatible?

You'll know if your soil is Perma-Zyme compatible by conducting a soil evaluation. You can hire a geotechnical firm to do this, but they can be expensive, time-consuming, and hard to find in rural areas. So, we started evaluating our U.S.-based customers’ soil for them with the #200 Finder Soil Evaluation.

We'll conduct this sieve analysis at no cost to check your soil type and particle size distribution, and we'll treat a small amount of your soil with Perma-Zyme to ensure that it will work properly. Then, we'll provide you with a detailed report about your soil's level of Perma-Zyme compatibility and any amendments it needs.

If you're reading this, you may have already taken advantage of the #200 Finder Soil Evaluation and got "incompatible" soil results. That's alright! We're about to tell you how to amend your soil. But first, if you haven't had your soil evaluation yet, now's the perfect time. 

What If My Soil Isn’t Compatible? 

If your soil is incompatible, you can still use Perma-Zyme with a few simple soil amendments. And thankfully, these amendments are still cheaper than most traditional soil stabilization methods, like chlorides or cement. 

Can I Go Ahead and Apply Perma-Zyme Without Amending My Soil?  

Technically yes, you can apply Perma-Zyme to incompatible soil. But, you run the risk of paying for Perma-Zyme and applying it to soil where it just won’t work. Since that would waste money, most people evaluate and, if needed, amend their soil.

That said, a few people have strategically treated slightly incompatible soil without making amendments. One county in Nevada successfully applied Perma-Zyme to gravelly, rocky soil that had less than the recommended amount of clay. The Perma-Zyme cured properly, and over the next month, the road became less dusty and more stable. However, the treatment may not last for a full 10 years, which is how long Perma-Zyme should last when mixed with compatible soil. 

For soils that are extremely incompatible, the treatment may only last a few days, or it may not work at all. Some customers who purchased Perma-Zyme and applied it without evaluating their soil first found that the soil crumbled less than a week after treatment because it was far too sandy, gravelly, or silty. 

That’s exactly the kind of situation you don’t want—and neither do we! It’s a good idea to take advantage of your #200 Finder Soil Evaluation or, for international customers and U.S.-based homeowners, your free do-it-yourself soil assessment kit. That way, you know what soil amendments you might need. With that in mind, let’s talk about how you can amend your soil to work with Perma-Zyme. 

Soil Amendments To Use With Perma-Zyme

The types of soil amendments you’ll need depend on why your soil is incompatible in the first place. 

Soil That Has Too Little Clay

For soils that lack sufficient clay, you’ll need to use limestone or decomposed granite soil amendments. 

People often use limestone or lime to amend soil because of their calcium and magnesium content. We recommend using crushed limestone with Perma-Zyme. You can also use decomposed granite, which is made up of tiny pieces of granite that have flaked or crumbled off their parent rock due to erosion and weathering. It has a sandy-rocky texture, and people often use it for landscaping. 

The fascinating thing about limestone and decomposed granite is that, while they are both natural soil amendments, neither of them contain organic matter like clay. So, how do they work with Perma-Zyme? Great question! 

Lime and decomposed granite are chemically complex. Lime contains both positively charged calcium cations and negatively charged carbonate anion groups. Likewise, the different types of granite each have positively and negatively charged particles; for instance, granite that's mostly made of quartz contains negatively charged oxygen and positively charged silicon.

So, the negatively charged anions in lime and decomposed granite react chemically with Perma-Zyme’s positively charged cations—even though they also contain positively charged particles and even in the absence of organic, clay-based material. (That's why soils with lots of natural, unprocessed limestone are also highly compatible with Perma-Zyme!)

The amount of lime or decomposed granite your soil needs depends on how much or little clay it has, as well as the size of your project. Our soil stabilization experts will make recommendations about the proper amounts in your soil report, and they’ll walk through those recommendations with you. 

Soil That Has Too Much Clay

Sometimes, you may even need soil amendments for clay soils. For soils with very high clay content, you’ll need to import aggregate. Then, the clay will be able to bond around these larger rock particles to give your soil greater shear strength and prevent crumbling. 

The great thing about adding aggregate is that you can also mix it into the top layer of soil during the Perma-Zyme application. This lets you create traction on unpaved roads, without having to constantly re-gravel them. After all, gravel prices are only going up; one county in Iowa was spending $1 million a year on gravel before they applied Perma-Zyme. With Perma-Zyme, you can simply import compatible soil and aggregate one time for stable, durable roads that last 10 years or more.


Perma-Zyme works best with clay-based and limestone-based soils, but you don’t have to give up on “incompatible” soil. You can still apply Perma-Zyme with a few simple, affordable, and natural soil amendments, and you’ll get the same great, long-lasting results! (Hey, 10 years of road stability is worth the one-time cost of importing lime, decomposed granite, or aggregate.)

If you've already completed your #200 Finder Soil Evaluation, contact your sales rep to talk about which soil amendment will be best for your project and your budget. They'll help you weigh your options and find the solution that's right for you!


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