How to Level a Concrete Floor Before Tiling

When we decided to spontaneously rip out the existing flooring in our laundry and thus launch a full room makeover, one of the first things we had to figure out was how to level a concrete floor before tiling.

I was definitely… umm… surprised when I heard the clunky sound of pry bar hitting hammer and came in to find Alex “just looking” underneath one of the tiles, but I’m glad he forced us into this makeover despite my being eight months pregnant and exhausted at the time.

There was tile across about three-quarters of the room but just the concrete subfloor on the rest and once the tiles had been ripped up, there was quite a bit of mortar left behind. We had the option to tediously chisel up the mortar until everything was flat, or we could just level over the entire floor to give us a flat surface to tile onto.

We obviously chose the latter (mostly because the floor seemed a little uneven to start with), and I think we made the right choice. I watched a lot of YouTube videos, read a lot of Home Depot product reviews and scoured contractor forums to figure out how to level a concrete floor before tiling and, I’m going to be honest, it feels totally badass to do but it’s really not all that difficult when you break it down.

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How to level a concrete floor before tiling

Tools and Materials:

Start with a clean surface

Once you’ve got your concrete floor cleared off and ready to level, the first step is giving it a really good, thorough cleaning. I know, this is the worst, but if there are specks of dust or debris then you risk the primer or concrete sticking to that rather than the floor which will give you not as strong a finish.

So, get your Cinderella on and sweep as intensely as possible – preferably use a Shop Vac if you’ve got one – and maybe even mop if you’ve got enough time to let the concrete dry out afterwards.

Prime the flooring

Once the floor is as clean as possible, roll a coat of concrete primer over the floor. This will go on with a milky consistency but will dry clear, and it usually takes about 24 hours to dry before you can move to the next step.

Spray foam around the perimeter

I thought this part was going to be fun but honestly I kind of hated it. Essentially, self-leveling concrete will – you guessed it – self-level which means it will just keep spreading out until it hits a barrier and level out from there. So, you want to make sure it’s got a perimeter which you do by adding a layer of spray foam around all the room’s edges and any pipes etc. For us, there were definitely some gaps along the wall’s edge and if we hadn’t used the foam, we likely would’ve wasted a lot of concrete inside those spaces.

Using the foam is really simple because it’s just a nozzle on a can but be forewarned: it’s the consistency of if marshmallow and silly string had a baby so it gets a bit wild.

Start in a corner (preferably the least visible space while you get the hang of the product), and start squeezing the trigger, layering the foam in the corner of the space all around until you’ve made an outer barrier for the concrete to be poured into. For any pipes or other obstacles, make as neat a surround as possible, though don’t worry too much about it being messy because the foam is really easy to clean once it’s set.

Mix and pour the concrete

This is the fun part. Figure out how many bags of self-leveling concrete you’ll need then add a couple more just to be safe (you can always return the bags but it’s a pain if you didn’t buy enough and your concrete is setting while you have to run to the store – ask us how we know!) Check the directions on your particular product but basically you’ll add water to the bucket then pour in the concrete mix, using the mixer drill attachment to consistently stir up the product. It should be a smooth batter-type consistency when it’s ready to go.

You’ve got to work quite quickly while doing this and we saw a lot of YouTube videos where the pros would mix up like five buckets of concrete at once, but since we’ve got a small space and weren’t sure how much we’d need, we did one bag at a time and were fine. Once the concrete is mixed and ready, it’s as easy as pouring it in the space, just make sure to start the farthest away from the door so you’re not getting yourself trapped on the other side of setting concrete!

The product is self-leveling but that doesn’t mean you don’t need to help it along a little bit. Once it’s poured it should be pretty obvious which parts need attention, like if there’s an area that the concrete didn’t reach along the edge or if it’s too deep in one spot, etc. If this is the case, use the squeegee to very gently guide the concrete into the gaps.

Then, rinse and repeat until the whole floor is done.

We found the best way to do this was having Alex mix up the concrete, then I would pour it and spread it around while he prepared the next batch. I think in total we used about six bags for our 6 foot x 12 foot room.

Let dry and get ready to tile

We were truly amazed at how good the floor looked once we’d let the concrete dry. I don’t know what we expected but it really was level (I should know because I watched Alex check about 857 spots with the level like a peak dad).

We’re so glad we took the time and effort to learn how to level a concrete floor before tiling. It was such a breeze once we got to the laying tile stage not worrying about bumps or slopes in the floor. The tile looks so good now and we feel like total pros having leveled our own floor.

We’ve done a lot more work in the laundry since this project and still have a lot more to come, so make sure to be following along on Instagram and subscribe to our newsletter for more DIYs.