Self leveling concrete can be a fast, efficient, and cost-effective solution if you need to smooth, repair, or raise a floor. Self leveling concrete is a mixture that mimics normal concrete. However, unlike concrete, it sets up much quicker and flows better. Usually, you mix it with water, pour or pump it into place, and spread it evenly over your chosen area using a gauge rake. Once it spreads out, your self leveling concrete will continue to flow until it evens itself out without any input from you.
Depending on the product you pick out, it can be flat and smooth in as little as one or two hours. In roughly six hours, the self leveling concrete may be 100% hard and ready to use, depending on which flooring medium you plan to put over it. You can use self leveling concrete as an underlayment for carpet, tile, or other flooring mediums. If you look for self leveling concrete but you can’t find it and you find something called “self leveling underlayment” instead, this is the same product under a different name.
Generally speaking, this concrete is a mix of Portland cement with polymer plasticizers and other ingredients. It offers the same level of strength that you get with concrete, but the flow is much smoother and it has a much quicker setup time. You can also pour this concrete to a quarter of an inch thickness, and this is just enough to smooth out any imperfections if that’s all you need to do. You can pour it as thick as an inch and a half without any aggregate and up to five inches thick with aggregate.
Self leveling concrete works very well with radiant heating installations because you need a material that will flow around the tubing. The thicker compounds used to level floors have to be troweled to get the proper finish, and they can’t work around the tubing well. If you have a moisture problem with the slab, you’ll need a professional to come in and do moisture remediation before you start your project. If you don’t and you’re ready to go, read on to learn everything you need to know about successfully using this medium.
Concrete floors are a very nice addition to your decor, especially if you add pigments to color them.
Where You Use Self Leveling Concrete
Let’s say that you have a project coming up to upgrade an old, damaged concrete floor that is cracked or settled. Or, you’re going to install a radiant heating system on your floor. Maybe you’re adding an addition and you need to match the floor to the existing floor in the adjoining room, or you’re going to finish your basement where you have an issue with uneven concrete.
Adding self leveling concrete works well for light industrial applications, warehouse floors, institutional facilities, and retail stores. You can add pigmented color dyes, saw cuts, stains, or mechanical polishing to give your concrete a decorative finish on the surface.
Self Leveling Concrete vs. Regular Concrete
Traditional concrete requires that you have a large amount of water to give it the fluidity required to pour it effectively. Self leveling concrete removes the need for using as much water while giving the concrete a nice fluidity level. It may surprise you to learn that self leveling concrete can be more fluid than traditional concrete, and some people have described the consistency close to pancake batter. Traditional concrete is much coarser and thicker.
What makes self leveling concrete stand out from traditional concrete is that it uses a high amount of polymers during the manufacturing process. Polymers are glue-like, unique molecules that work to bond your substance together, and you can find them used in everything from wood and leather to metal coverings, paints, and computers.
On a gallon-for-gallon basis, self leveling concrete is more expensive because of the additional cost required to manufacture it. However, this is a very versatile substance that you can use instead of having to go in and demolish damaged concrete before replacing it. Most home remodeling businesses don’t even know that this concrete exists, so they spend a lot of time tearing up old concrete that looks like it’s too damaged to use. Instead, you could pour a ½-inch thick layer of self leveling concrete to improve the aesthetic immediately.
Using Self Leveling Concrete
For anyone who is looking for a nice weekend DIY hard floor solution, self leveling concrete could be a viable option. This blended concrete product is easy to make, and it dries in just a few hours, and this gives you a standalone option or subfloor that looks great and withstands heavy traffic well. However, if you’re not familiar with concrete or how to mix it, this is for you. We’ll walk you through how to mix and use self leveling concrete for small and large projects below. It generally takes between one and eight hours from start to finish, including the drying team.
Tools and Materials Needed:
- 1 or more bag(s) of self-leveling concrete, water
- 1 quart or more bottle(s) of primer
- 2 mixing barrels/buckets at a minimum
- Leveling compound rake and squeegee trowel
- Mixing tool
Step 1. Consider Your Floors and Location
First things first, will your floors benefit from adding a layer of self leveling concrete, or is there a different solution that works better, like bringing in a concrete repair specialist? Self leveling concrete is very effective for uneven, split, or cracked flooring. It works best when you use it as a subfloor for carpet or tile, or you can use it as a standalone surface inside. Anyone with a radiant heating system can also be prompted to use self leveling concrete to cover up the heating elements.
On the other end of the spectrum, outdoor surfaces really aren’t the best choice for self leveling concrete. This is due to the fact that it’s a combination of polymer and concrete, and this spreads easier than traditional concrete but it won’t set on uneven surfaces and it’s not as durable.
Step 2. Prepare the Floor
The preparation process is the key to having a successful DIY self leveling concrete project, especially if you’re putting it over existing concrete. Poor prep work will lead to a weak bond between the old and new concrete, and this increases your chances of cracks or chips down the line.
Be sure to:
- Apply painter’s tape to protect fixtures or pipes
- Clear away any debris
- Dam up any gaps around the perimeter that leads to doors, vents, or pipes
- Screw or nail down any loose flooring
- Vacuum the floor
As part of the prep work, get a few additional bags of self leveling concrete online or at the store. A standard bag will typically cover 50 square feet poured to ⅛ inch thickness. Even a slightly greater thickness can mean the use of several more bags. Akona, LevelQuik, Henry, and Sikafloor are all popular brands to consider.
Floor preparation is key when it comes to using self leveling concrete to help ensure that you get a solid seal.
Step 3. Prime the Floor
Applying primer is extremely important to ensure that you get a strong, smooth finished surface. Before you move on, make sure to read the manufacturer’s instructions for the specific product you pick out. Most primers you work with are water-based acrylic ones. They help to retain moisture and ensure that your self leveling concrete cures correctly once you apply it. Pay very close attention to the required amount of time it needs to dry before you add it. Plus, some products strongly recommend that you use one type or brand of concrete with their primer.
Step 4. Apply the Self Leveling Concrete
After waiting for the recommended amount of time, you’re ready to apply your self leveling concrete. You may want to get a partner to help you as they can mix a fresh batch while you apply the current one. You want too be sure to:
- Add the correct amount of water to your concrete as outlined by the instructions on the package. If you add too much or not enough, you’ll get inconsistencies and lumps.
- Mix and pour quickly so you get an even drying time.
- Pour heavily and allow the concrete to flow and thin out.
- Start on the far side of the room and work backward, toward the exit.
- Use the squeegee trowel or leveling compound rake to get rid of any bumps or inconsistencies before it hardens.
If you’re working on a larger area, it may be worth it to buy or rent a mixing barrel with latches. This will keep your concrete from drying as you apply it to your floor, and it can reduce your stress as the sense of urgency throughout the project won’t be nearly as high.
Step 5. Let it Dry and Assess
Some self leveling concrete products are made to have rapid-drying that can dry in less than an hour after applying them. Other products can take up to six hours to dry. Once it’s dry, look for pinholes, small bubbles, or any inconsistencies. You should be able to gently scrape them away if they’re right at the surface.
Finally, take any tools you used to apply your concrete and clean them. If you allow the concrete to dry on them, the compound won’t ever come off. You can enjoy your floors as they are now, or you can continue building on and use it as a subfloor.
How to Pour 1-Inch Thick Concrete
There aren’t many reasons why you’d want to have a one-inch thick concrete surface. It’s too thin to use by itself as a flooring substrate. However, if you need to resurface damaged concrete, this is a great amount. The old surface has to get prepared to accept the new concrete. You’ll also need to add a frame to hold the new concrete in place until it hardens.
To start, build a frame for your concrete. Build it around the damaged concrete so that a minimum of an inch of wood extends above the old concrete. Measure around the spot and cut boards to fit. Drill holes in the boards with two inch screws.
Drill stakes onto the outside edge of the boards using two-inch screws. Hammer the frame into the ground until an inch of wood is rising above your old concrete. This forms the support to keep the wet concrete inside.
Mix up a concrete overlay with one part portland cement and 2 ½ parts sand. Add water until you get a consistency that is like wet, thick mud. It doesn’t need to be thin enough that you could pour it like a liquid, but it also shouldn’t be thick enough to cling to the trowel. Try for thick milkshake consistency.
Dump your concrete into the frame and spread it out using a trowel. You can now leave it to dry. Or, if you would like to add to the surface, now is the time to stamp it. You have to wait to stamp the surface until it sets up enough to hold the indention. Put your fingers to the surface of the concrete to test it. If the indents remain, you can start stamping. Stamping needs a concrete releaser sprayed so that you can pull the stamps back out after you set them into the cement. Place the stamp forms in and press down firmly, and then continue until you finish your area.
You’d rarely need to have a one-inch thick concrete layer on the floor, but it’s nice for stamped surfaces to ensure you get a good pattern.
Pour a Leveling Layer of Concrete Over an Existing Uneven Concrete Floor
Do you have an old patio or concrete floor that isn’t even? If so, you can level an existing concrete floor by adding a new leveling layer of concrete. However, you do have to prepare the old floor first. If you don’t, this prevents the new layer of concrete from adhering correctly. This will result in a weak bond between both layers. When you prepare it correctly, a leveling concrete layer increases the strength and longevity of the old floor. The following will outline how you pour a leveling layer of concrete.
1. Mark the Measurements
Mark the height you want the new concrete to be. If you’re working inside, you can put a chalk line around the walls. If you’re working outside, you want to dig a perimeter of the floor four inches deep. Put wood form boards on their sides inside of the trench and nail them together at the ends. The surface of the new concrete will be level with the top of your form boards. So, if you plan on raising the level by two inches, you’ll want to use 2 by 6 form boards.
2. Pour the Concrete Etching Acid
Pour your concrete etching acid over the surface and use a shop broom to spread it around. Scrub the acid into the flooring and wait a half of an hour before rinsing it away using a hose.
3. Rough up the Floor’s Surface
Go over the surface of the floor using a wire brush to rough it up and help the new concrete adhere to it better. Water the old concrete to stop it from absorbing moisture from the new.
4. Mix up the Concrete
Prepare enough concrete to pour a one or two-inch layer over the existing floor. In a concrete mixer, add water, aggregate (if you’re using it), and cement in ratios directed by the manufacturer on the package.
5. Pour and Spread the Concrete
Pour your concrete over the existing floor and spread it over the surface using a rake. Continue pouring the self-leveling concrete until you reach the height of the top of the form boards or the chalk line.
6. Smooth the Concrete Surface
Settle the concrete using a clean straight-edge long enough to drag across the surface of the floor. Smooth the surface with a float starting with the first section of poured concrete and working across. Remember, self leveling concrete shouldn’t need a lot of help in this area. At most, it’ll need a small push to get started before it levels out.
7. Allow it to Dry
Finally, allow your concrete to dry. This can take anywhere from two to eight hours, depending on the brand.
Self Leveling Concrete – Important Considerations
If you’ve followed the steps we outlined above for using self leveling concrete, you’ll be able to do a decent job of installing this concrete on any floor. The following tips are good to keep in mind too:
- Buy more self leveling concrete than you think you necessarily need. If you alter the thickness after you buy it, you may not have enough to do the whole floor. You also can’t go out and buy more during the job as it will most likely set up by the time you get back.
- Clean up the buckets, tools, and equipment as soon as you finish the project. Once the solution dries up, you won’t get it back off.
- Don’t add more concrete than you need ot your mixing ratio will be off and you’ll ruin the whole batch
- Don’t add water after you add the concrete as you need an exact mixing ratio
- Don’t mix the concrete and water in extremely hot or cold weather
- Keep your bags of self leveling concrete in a dry and cool place, and make sure you protect if from moisture
- Prepare all of your supplies and tools in advance so you don’t waste time when you’re pouring the concrete
- Read the instructions on the bag before you start your project
Larger Rooms Tips with Self Leveling Concrete
A larger room means that you’ll have to pour buckets of concrete, run back to your mixer, mix up a second batch, go back to the room with another full bucket, pour it where you left off, and repeat. Larger rooms are much easier to tackle if you have two people working with one mixing the concrete and one pouring it. You also want to use a stiff squeegee on a long broom handle to help nudge the concrete in place.
- Caution: Wet concrete is caustic and it can easily burn you.
It’s a good idea to wash off immediately if you happen to walk through any wet concrete. Don’t walk through it if you have any open cuts as it can hurt. If you find bits of unmixed clumps of cement, you can break them down with your fingers to get a smooth surface. Also, you may need a second coat if the first one doesn’t cover 100%. If you can still see the concrete under it, you’ll need another layer.
If you’re covering a larger room, enlist the help of a friend or family member so you can ensure that you get the full floor poured before it starts to harden.
Why Use Self Leveling Concrete?
With as much self leveling concrete as you’ll need on your flooring, the obvious question is why you’d want to use it in the first palace. The biggest reasons include but are not limited to:
- Resurface and Entire Floor – When cracking, pitting, or splitting happen and it turns into a problem that you can’t fix using traditional concrete patching compounds, self leveling concrete is a great alternative to tearing it up and starting over.
- Standalone Flooring Material – The industrial, raw look that natural concrete offers can make a great look to a host of different themes. Coloring additives in this type of concrete can create an interesting finish and help it complement any planned or existing decor, accessory, or paint.
- Uneven Spots or as a Spot Fix – Polyurethane injections or mudjacking are the only solution to fix uneven slabs. However, many uneven or flat slabs can be corrected by grinding the slab and using a self leveling concrete to smooth it out again.
No matter why or how you use it, self leveling concrete can be a very cost-effective flooring solution. This is especially true when you have a project that would have required you to demolish the existing floor, subfloor, or foundation. If you can save your floor by adding a ½ inch thick layer of self leveling concrete to revitalize it, it’s a win-win for everyone.
However, as versatile and efficient as this substance can be, there are instances where it may be better to use traditional concrete over the self leveling option, and we’ll outline those next.
When You Shouldn’t Use Self Leveling Concrete
For most instances, self leveling concrete is used for interior flooring, either as a standalone surface or as a topper for carpet or tile. There are some indoor/outdoor uses that can make sense too, like an exposed but covered garage floor. However, most 100% outdoor spaces won’t work well for self leveling concrete.
Also, any vertical surfaces you have aren’t appropriate for self leveling concrete. This is because polymer-mixed concrete in this category is a lot more slurry-like, and it doesn’t cure well if you put it on a horizontal surface as it’ll run down the wall and pool on the floor.
You also don’t want to use this concrete in areas where you have harsh chemicals present or where you’re going to operate heavy machinery. This is due to the fact, even as smooth and good-looking it is, self leveling concrete isn’t nearly as resistant or structurally sound as normal, thicker concrete.
Now you know how to pour self leveling concrete, and you can take this information to repair or pour indoor flooring as standalone surfaces or as a subfloor. It’s a very DIY-friendly project, even for beginners that you can take on by yourself or with a partner for a weekend project.
Jen is a master gardener, interior designer and home improvement expert. She has completed many home improvement, decor and remodeling projects with her family over the past 10 years on their 4,500 sf Victorian house. She is also a passionate farmer who keeps goats, chickens, turkeys cows and pigs on her farm, and an instructor for her community’s Organic and Sustainable Farming project.