If you are looking to build or repair something in your home, particularly something that is built with cement or concrete, then you might be tempted to use either hydraulic cement or epoxy. Now, both are viable options no doubt, but it does of course depend on what exactly you need to accomplish, what your budget is, and more.
Let’s figure out which of the two you need.
Hydraulic Cement and Epoxy: The Basics
Before we talk about the similarities and differences between hydraulic cement and epoxy, let’s first figure out what both of them are.
What Is Hydraulic Cement?
Hydraulic cement is a very special type of cement, with one of the defining characteristics of it being that it has the ability to cure when wet, even when underwater. The number one use of this type of cement is for structures and buildings that are always or often in contact with water, due to the fact that it is waterproof.
In other words, it is used to stop water leaks in concrete structures, as well as masonry structures. Hydraulic cement is made out of a variety of components including alite, belite, celite, and brownmillerite. The alite and belite help produce great strength when hard, and the latter of those four substances helps keep it in its initial liquid state before use.
What is Epoxy?
Epoxy is probably a substance that you are most familiar with, and generally speaking, these will be two-part, although they may also be one-part. Generally speaking, epoxy is made by mixing two compounds, a resin and a hardener, which then causes a catalytic reaction, or in other words, when the two substances mix, the curing process begins.
Epoxy cures via exothermic reaction, which means that heat is created when curing happens, and the more heat occurs, the better and stronger the cure.
In terms of uses, you are probably most familiar with epoxy being used as an adhesive, and in fact, due to its awesome bond strength, it makes for an excellent substance for a variety of repairs. In terms of the epoxy used for masonry, stone, and concrete repairs, keep in mind that it generally expands to up to twice its original volume (which normal epoxy adhesives generally don’t do).
Similarities of Hydraulic Cement and Epoxy
Now that we know what both hydraulic cement and epoxy are, let’s figure out what some of their shared similarities are.
1. Both Can Be Used for the Same Applications
One of the primary similarities here is that both of these substances may be used for the same purposes, at least some of them. In relation to today’s article, both of these substances can be used to make repairs on stone, masonry, and concrete, with the main goal being to waterproof surfaces. Now, with that being said, epoxy does have a wider range of applications, mainly because it is also used as a general adhesive.
2. Both Can Be DIY
Right off the bat, beware that to repair masonry or concrete using either of these substances, you do need to be familiar with them and you need to know what you are doing, but that said, you can definitely work with both of them on your own without having to call in the big guns.
3. Both Create Water Barriers
The other and perhaps the biggest similarity that these two substances share is that they are ideal for waterproofing. Both hydraulic cement and epoxy end up being totally waterproof once cured, thus making them ideal for fixing cracks in walls and foundations.
4. Curing Underwater
Now, although these two substances do cure slightly differently, one big similarity that they share in this regard is that they can both be applied and cured underwater.
Differences Between Hydraulic Cement and Epoxy
Now that we know what makes epoxy and hydraulic cement similar, let’s figure out what makes them different.
1. Composition
The biggest difference here is that both are made of, with hydraulic cement being made mainly of alite, belite, celite, and brownmillerite, and moreover, when it cures, it forms what is essentially rock or stone. On the other hand, epoxy is made out of polymers which react with each other, usually a resin and a hardener, and moreover, when they cure, they form what is essentially plastic. It’s technically a little more complicated than this, but then again, we aren’t here for a chemistry lesson.
2. Bonding to Concrete and Other Surfaces
What definitely stands out about epoxy is that besides very smooth plastic, it will bond to everything and anything. On the other hand, while hydraulic cement is ideal for stone and masonry repairs, as well as for cement repairs, it doesn’t bond all that well with other materials, especially concrete.
3. Epoxy Penetrates More
One of the biggest benefits that you get with epoxy is that the specific kind we are talking about today actually expands up to two times its original volume, thus filling in all of those little cracks with ease and allowing for excellent penetrative waterproofing. Hydraulic cement on the other hand may actually shrink as it cures.
4. Overall Strength
You might think that cement would be stronger than epoxy, but this is actually not the case. Epoxy is stronger and has more tensile strength. Epoxy can also be a bit flexible when cured, which cement is certainly not.
Hydraulic Cement vs. Epoxy: Which of the Two Should You Use?
If you are looking to do some waterproofing for swimming pools, basement walls, foundations, drainage systems, manholes, and other such structures, then hydraulic cement is what you want to go for (when building new). However, if you are making repairs and you need great waterproofing, then epoxy is the way to go, particularly for concrete and any material that hydraulic cement won’t bond to.
Summary
Both epoxy and hydraulic cement have their uses, but with that being said, epoxy does appear to be the more useful of the two. Of course, it does all depend on the specific application at hand.