When it comes to flooring materials both gypcrete and concrete have their respective roles, with most people being far more familiar with concrete vs gypcrete. Gypcrete, although it has a similar sounding name to concrete, is actually a flooring underlayment used for its self-leveling, sound-reduction, and radiant heating abilities.
Concrete and gypcrete share a lot of the same properties, however, there are some significant differences to be aware of when picking a material.
Let’s take a close-up look at both gypcrete and concrete in more detail, so you can choose the right material for your flooring application.
What is Gypcrete?
Gypcrete is a cement-like mixture consisting of sand, Portland cement, and gypsum. Gypsum is the major differentiator between gypcrete and concrete and is the same stuff that’s found in drywall which is sometimes called ‘gyprock’ or gypsum board.
Gypcrete is primarily used as a flooring underlayment material and has the advantage of being lightweight, somewhat self-leveling, sound-reducing, and providing radiant heating. Its light weight makes it an attractive choice for flooring underlayment because of this.
Keep in mind, gypcrete is not meant to be used on its own, rather it’s meant to be used underneath a layer of flooring material like carpeting or wood flooring. Unlike concrete, applying gypcrete is not really a DIY affair, as it must be mixed and poured correctly by an expert.
What is Concrete?
Concrete is pretty straightforward stuff, and it gets used for all types of construction applications. Typical concrete contains a mixture of Portland cement, sand, and gravel. Of course, water must be added to the mixture in order to activate the cement and begin the drying and curing process.
Concrete gets used for all sorts of things, including sidewalks, slabs, fence posts, driveways, and full-sized structures.
The exact mixture of concrete that gets used varies depending on the application, with some fast-setting mixes containing an accelerant like calcium chloride to speed up the drying and curing process. Other mixes will vary in their ingredient ratios, with higher compressive strength concrete having a higher ratio of cement to aggregate.
Similarities and Differences of Concrete vs Gypcrete
Let’s get down to the nitty-gritty of the differences between concrete and gypcrete so you’ll have a solid understanding of which is best for you.
First up, Gypcrete is significantly lighter than concrete, which is an advantage in terms of ease of use and application. If you compare the weight per square foot, gypcrete weighs in at 13 pounds per square foot, while a typical concrete mix weighs in at 18 pounds per square foot.
The standard concrete mix will cure to a higher compressive strength than gypcrete. Gypcrete will only cure to a compressive strength between 2,000 psi and 3,200 psi, while concrete varies between 2,500 and 5,000 psi depending on the specific mixture.
Concrete is more suitable for areas that will be exposed to water than gypcrete. While concrete is not 100% waterproof, it’s pretty close to it and will resist even prolonged exposure to water.
There are also concrete mixes with additives which essentially make the concrete completely waterproof.Gypcrete is not meant to be used in areas exposed to water and will break down over time due to gypsum’s solubility in water. Of course, if the gypcrete is properly covered, then some moisture exposure is not going to be a major issue.
Gypcrete claims to be self-leveling, but in practice, it tends to require some troweling to get a nice smooth finish. Concrete will require screeding, edging, and floating to get a nice smooth finish.
Concrete takes longer to cure than gypcrete, but it dries enough to walk on in as soon as 24 hours. Gypcrete, on the other hand, takes only 90 minutes to cure. This can be a nice advantage if you’re on a tight schedule and need to start working on the flooring right away.
Gypcrete is generally more expensive than concrete, costing about double what standard concrete mix costs. There is some variation here though, as both concrete and gypcrete will vary in cost depending on the quality of the mix and ingredients used.
Concrete is generally applied in a thicker layer than gypcrete is, which is typically applied in a relatively thin application.
Gypcrete is often used in radiant heat flooring systems because unlike concrete, it won’t cause corrosion around the heating tubes. Concrete on the other hand will cause corrosion, which is why it isn’t used for this application.
One thing to keep in mind though is that concrete is actually the superior product for conducting heat. It will retain heat for longer and stay hot for longer.
Concrete is significantly more durable than gypcrete, as it’s designed to be a structural building material.
Gypcrete, on the other hand, is designed specifically as a flooring underlayment material, so it doesn’t need to be quite as durable. It’s also spread in a very thin layer, unlike concrete which is normally applied in thicker applications.
Shrinking and Cracking
When it comes to shrinking and cracking both concrete and gypcrete have their issues. Concrete must be cured correctly in order to avoid shrinking and cracking, while gypcrete is known for having issues with shrinking around heating tubes and cracking around the edges.
When it comes to adhesive properties, gypcrete is the winner. It bonds to vinyl-coated wood very well, making it the ideal choice as a subfloor for this material. Concrete does not bond well with vinyl-coated wood flooring, so it makes a poor choice for this material.
It’s also worth mentioning that gypcrete doesn’t work well with nail-down wood flooring, as it doesn’t take to holding nails.
Gypcrete vs Concrete: Which one is better for you?
When it comes to choosing between gypcrete vs concrete, you’ll need to consider what the job requires.
Gypcrete is the superior choice for flooring underlayment in the majority of cases. Concrete, on the other hand, is the better option for general construction use, such as for sidewalks, fence post anchors, slabs, columns, and the like.
Featured image source.