Gypcrete vs. Concrete: Which to Use?

Gypcrete vs. Concrete: Which to Use?

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In terms of the most common and popular building materials out there, concrete is definitely at the forefront. However, there are other common building materials out there that are related to concrete, with the main one being gypcrete.

Now, concrete and gypcrete are similar in some ways, but they do also have fundamental differences, particularly in terms of their primary applications. What we are here to do right now is to figure out what both of them are, what similarities they share, what the differences between them are, and what they are both best used for.

Gypcrete and Concrete: The Basics

Before we get into talking about what the similarities and differences between the two are, it’s probably a good idea to first figure out exactly what both of them are, so let’s do that first.

What is Gypcrete?

Gypcrete is closely related to concrete, with some people referring to it as concrete’s cousin. Gypcrete is made out of a mixture of sand, concrete, and gypsum plaster, hence the named gypcrete. For those of you who don’t know, gypsum is actually the material that is present in the middle of drywall.

In terms of the application of gypcrete, it is most often used as floor underlayment in both concrete and wooden frame constructions. It is also used for sound reduction, radiant heating, floor leveling, and fire ratings. Gypcrete or gypsum concrete was first used in the radiant heat flooring industry for use with copper heating tubes, as normal concrete was far too corrosive on the copper tubes.

What is Concrete?

Concrete is of course one of the most common building materials around, one that is made out of cement, water, aggregates, and sometimes reinforcements too.

What is important to note is that there are many different types of concrete out there, potentially in terms of the aggregates and binders. For instance, there are various types of cement concrete, as well as others, such as asphalt concrete that used bitumen as the binder, something that is often used for road paving. There are also various concrete mixes in terms of the ratios of the materials used.

Concrete is a commonly used building material that is used for roads, sidewalks, driveways, foundations, walls, and more. When it comes to the applications and uses of concrete, it is an extremely common and widespread building material that can be found nearly everywhere.

Similarities of Gypcrete and Concrete

Now that we know exactly what gypcrete and concrete are, let’s find out what similarities they share.

#1: Both Are Made with Cement

One of the most basic similarities shared by these two building materials is that they are both made using cement combined with other materials. The type of cement used is usually Portland cement.

#2: Both Take Quite a While to Dry and Cure

Another similarity that both of these building materials share is that they can take several days to dry and can take weeks to cure. Concrete and gypcrete, depending on the conditions, can both take as long as 28 days to achieve a full cure.

#3: Similar Compressive Strength

What is interesting to note is that although gypsum is much lighter than concrete, they both have about the same compressive strength, which is why gypcrete is a material of choice for floor underlayment.

#4: Susceptibility to Freeze-Thaw Cracking

Although gypsum is known for being a bit better on this front, the reality is that excess moisture, particularly when freeze-thaw cycles are involved, will cause both gypcrete and concrete to crack. That said, usually, these cracks can be fixed.

Differences Between Gypcrete and Concrete

Now, let’s get into the differences – something that will be key in helping you choose the better of the two materials for your job.

#1: Cost

One of the first noticeable differences is that gypcrete is generally cheaper than concrete, but depending on the mixture, can also be more expensive. Gypcrete costs between $1.75 per square foot to $6.00 per square foot, whereas concrete costs $2.50 to $4.50 per square foot.

#2: Weight

Another notable difference is that gypcrete is much lighter, with it weighing about 13 pounds per square foot, whereas concrete weighs about 18 pounds per square foot.

#3: Ease of Use

Although we won’t get into specifics, due to the various properties of gypcrete, as well as its lightweight nature, it does tend to be much easier and faster to work with than concrete.

#4: Concrete Holds Heat Better

Ok, so we know that gypcrete is the material of choice to use when surrounding radiant floor heating systems, but this is not actually because gypcrete holds heat better, but because of the next reason we will discuss. Concrete actually conducts heat better and holds onto it for longer than gypcrete.

#5: Gypcrete Won‘t Corrode Metal Tubes

The reason why gypcrete is used for radiant floor heating systems is that the heat will not cause it to shrink around the tubes, and it also won’t corrode the tubes. Concrete will do both of those things.

#6: Adhesive Properties

One big difference why gypcrete is a material of choice for floor underlayment is because it sticks well to vinyl-coated wood, whereas concrete does not. While concrete does adhere to and bond with many materials, the bond is often not all that strong.

#7: Driving Nails

Another reason why gypcrete is used for flooring underlayment is that you can actually drive nails through it without damaging it, something that you cannot do with concrete.

#8: General Composition

Although we are not going to get too deep into it, these two building materials are made with different components. Refer to our basics section under the introduction for a more detailed explanation.

#9: Primary Applications

Gypcrete is usually used for things like fireproofing, floor underlayment, soundproofing, radiant heating systems, and more. However, for anything structural in nature, like foundations, walls, floors, and more, concrete is what is needed. Gypcrete is not structural in the least.

#10: Fire Resistance

Another reason why gypcrete is a popular building material is that it does actually have a higher fire rating than concrete.

#10: Sound Dampening Properties

Gypcrete is much better at dampening sounds and vibrations than gypcrete is.

#11: Overall Durability

The reality here is that concrete is stronger and more durable overall, particularly when it comes to abrasion resistance. Gypcrete will quite literally crumble into sand over time.

#14: Gypcrete Is a Bit Softer

Gypcrete is just a bit softer than concrete, another reason why many choose it for floor underlayment.

Gypcrete vs. Concrete: Which of the Two Should You Use?

When it comes down to it, for anything structural in nature, such as for driveways, sidewalks, floors, foundations, and load bearing walls, you need to use concrete. However, for simple floor underlayment, for use with radiant heating, for fire and soundproofing, and for other such non-structural applications, gypcrete is the material of choice.

Summary

At the end of the day, both concrete and gypcrete are good building materials, but they just don’t have the same applications. Choosing the right one is of course essential to the overall success of your final project.