Before we get started

Before we get started with the floor leveling,  there are a few tools  you will see that I use in this step. Most of these tools you probably already own and if you don’t, then you will need to get these tools to be able to do this yourself. They are tools that you will need to install the tile anyway, so you should be covered. More on what you need later.

I am going to simplify floor leveling as much as possible. Just be sure to follow these simple steps that I will layout for you and all will be good.

Tools and supplies that you will need for floor leveling-

  1. 4ft level or straight edge(if you don’t have one that is okay)
  2. Chalk line
  3. trowel with a flat side(you can use the back side of your tile trowel)
  4. modified thin set
  5. carpenters pencil(the rectangle pencil you can get at the lumber yard)
  6. bucket and water
  7. sponge

Tip 1- Stretch out a chalk Line to find dips and humps

Whether the room is 20 x 20 or 4 x 5 the methods are the same for floor leveling. Have someone help you with this by holding one end of the chalk line. Stretch the chalk line out across the room, both ends should be held on the floor. Now check to see where there are any dips and humps in the floor and continue to move the chalk line around the entire room. The chalk line never lies and it will reveal all the problem areas to you.

Once you see where the problem areas are, you can then concentrate on those areas alone. So what I mean is, if you see a dip when looking down the chalk line(and you might need to get your head down to the floor to really get a good look down the chalk line) then move to that area and shrink up the chalk line. Now you need to mark where the dip begins or where the hump begins. Just keep moving the chalk line around and mark the floor where these areas begin and end.

If it’s a hump, then write that on the floor and the same goes for a dip.

Humps can be ground down with a grinder(concrete) or belt sander(wood sub floor). If you do not have one, it can be rented for a reasonable price.

Dips can be filled with thin set and I have a super simple method for this.


Tip 2- Use at least a 4ft Level or Straight edge to find dips and humps

This is really going to be the same exact floor leveling  strategy that we talked about above. The only difference is, it will take longer to cover a bigger area. I usually use the chalk line to find the bad areas and then use the straight edge to pin point the exact locations of where they begin and end.

Once you find a bad area, it is a little easier to just slide the straight edge or level around and mark these areas out. This is my preferred method .

You might not be able to use a 4  ft level or straight edge if the area is too small for these to fit into. 


Tip 3 – Find out how deep the dip is

Once you have marked out the dip, you will need to find out how deep it is. I do this by resting  either the chalk line or straight edge over the the area.

Then I measure it with a tape measure. You could also hold you tile trowel with notches next to the straight edge or chalk line. This is a quick guide to see if the dip is deeper than the notch in your trowel.

If the dip is deeper than your notch, you would either need to get a trowel with a bigger notch or we will have to do the floor leveling in a couple of steps. That would be okay, so no worries! If the notch is too big, that is even better and I’ll explain in a moment.

Tile trowels come in many sizes – click here to see chart

Most of the time when using a 12 x 12 or 13 x 13  tile,  I use  a 1/4 x 3 /8  square notch trowel.


Tip 4 – Fill the dip

Now that we know what trowel we need to use let’s start the floor leveling process and fill this dip. Mix up some thin set. I usually only mix about 1/2  of the bag at a time. Mainly so I don’t mix too much and it’s just easier to mix up in smaller batches. You could mix smaller or larger batches.

Once the thin set is mixed, I then use my tile trowel(the notched side)  to spread the thin set over the dip in the floor. I will stay within the lines that we drew on the floor in Tips 1 and 2. I will then pull my trowel across the floor trying to leave nice even tracks. 

Now you are ready to rake the dip. I use my straight edge and pull it across the dip collecting any thin set that will not be needed. This will eliminate the dip and all that should be left is the thin set that is needed to fill the dip. You might need to scrape the dip more than once, but be careful not to pull out too much. Always try to hold the straight edge the same way each time to avoid taking out too much.

Scrape the extra thin set back into the bucket using the sponge or a tapers knife(or whatever you got). Be sure to clean off your straight edge or level. Thin set is very hard to get off if you let it dry on these tools.

Tip 5 – Grinding a hump-


I would recommend renting a grinder that has a vacuum attachment on it. This will minimize dust. Never run your vacuum without a filter and when I say vacuum, I mean a wet dry vac!! Don’t use your household vacuum.

When floor leveling a hump, grind from the middle to the edges. Try to make even passes. Then stop and check the hump with your straight edge frequently. This will stop you from taking too much off. This is usually a pretty easy process and I know you can do it.

Wood Sub floor-

If you have a hump in a wood sub floor then a belt sander will be the best tool to use. You Don’t want to take too much of the sub floor away, this will weaken the floor. Unless you add another layer on top to give it it’s strength back. For example, you could add a 1/2 inch layer of plywood or OSB after you sand the hump down.

This will add additional height to the floor, which can also cause problems with door clearance and other things like that. So think it out first.

Tip 6- Final Filling

Go around the areas that were filled and clean them up a little. Scrape off any excess thin set that was not needed and give it a quick vacuum.

Wait for the thin set to completely dry before moving to this step.(usually over night). You can speed this up by using a rapid set thin set  It will dry within a few hours, however it is a little more expensive.  You can find this at Lowes, Home Depot and Menards.

Once dried, you now need double check with your straight edge to see if you filled the dip completely. Don’t worry about the tracks from the trowel, we will be dealing with that shortly. If it wasn’t filled completely and the dip is still deeper than an 1/8 of an inch than you can repeat tip 4. Otherwise we will catch the rest in a moment.

Now we  need to fill in the tracks that were left from the trowel. So mix up a little more thin set and apply it over the dip. This time we want to use that flat side of the trowel. If the dip needs a little extra thin set, than you can scrape over the dip with the straight edge once more. If all you needed to do is fill in the tracks then you don’t need to scrape it, just make it smooth.

It really does not need to be perfect, just get flat and when you spread the thin set while installing the tile, it will take care of the rest.



Thanks for your time,


Did you know Jesus paid the Price for us to Live?