You’d be surprised to learn how many older properties have uneven wood floors, which can be a bit of a turn-off for potential buyers or a bit of a pain if you notice it in your house.
This is mostly because old houses were built without foundations like houses today are, meaning the ground beneath them can shift as it settles, taking the walls and floors with it.

Even in modern houses, however, wooden floors can warm or become uneven through general wear and tear around the joints such as particularly heavy footfall in certain areas.
Whether your floors are wonky, sloping, or just plain uneven, you may be wondering how to level an uneven wood floor and how much it will cost you for the sake of flawlessly flat floors.
Luckily, this article by WFC has got you covered.
How To Prepare
Before you get started, inspect the wooden floorboards to determine what type of condition they’re in and identify any areas where they look especially uneven.
If any of your floorboards are starting to show signs of mold or rot, remove and replace them.
You should also keep an eye (or in this case, an ear) out for any loose or creaky floorboards as you will need to secure these properly before you lay your new flooring down on top.
Finally, check for any protruding pipes or cables under the floorboards by using a pipe and cable detector to make sure you don’t end up accidentally putting your screws into anything.
What You Will Need For The Job
The basic tools and materials you will need include:
- Wooden floorboards
- Nails
- Hammer
It’s a nice, short list!
How To Level Uneven Wooden Flooring
If you are leveling your wooden flooring yourself, here are the steps you will need to follow:
Step One
Purchase new, sawn timbers for your floor. You will usually get the best deal from your local builders or timber merchants.
Before purchasing your materials, check each joist by placing it on its narrow side down on a level surface. Wonky timber won’t fix wonky floors!
Check to see how much support there is in the existing joints, as you may require “joist hangers” which are also supplied at your local builder’s merchants which add extra support.
Start with the two joists at either end of the floor and fix a string to the top of the two new joists, as this will show you where the height of each joist needs to be to ensure a level floor.
Step Two
Now it’s time to lay your floorboards.
When you’re happy with the placement and level of your joists, turn your attention to the layout of the floorboards that need replacing.
These will need to run at right angles to the joists, no matter what size the room is, so you should base the layout of the flooring on this.
You will also need to work out how many boards you will need. Make sure to take careful and accurate measurements or alternatively, you could use a piece of offcut board to mark out each of the board positions on the joists.
Remember to keep in mind that you may need to work in “trimming joists” if the room contains a fireplace or a chimney, or anything else that protrudes from the wall.
Once everything has been marked out and planned, place the boards in their positions and fix them down so they’re secure.
How To Level Sagging Floors

Another reason for uneven floorboards could be to do with the joists underneath the floorboards rather than the boards themselves, in which case you may need to level the foundation by using a self-leveling compound.
Step One
The first step is to pour self-leveling underlayment to cover the uneven surface area.
This can help to correct sags or dips in the floor that are up to 1 ½ inch deep. Mix up your self-leveling compound, which is usually sold in powder form, until it becomes a liquid.
Step Two
If there are sagging joists that require additional support, you can “sister” them with another board using bold, nuts, and washers to ensure both boards are well supported and secure.
Lay Down New Hardwood
Another option is to lay down new hardwood over your uneven floor, using a plywood subfloor to bridge any gaps or areas where the floor is not level.
A self-leveling compound would also be used here, although you will need to make sure that your joists are strong enough to withstand the extra weight that the plywood and new flooring will add to the surface of your floor.
If needed, you can sister the joints or add adjustable columns to provide additional strength.
What Are The Costs of Hiring a Professional?
If you don’t have the time or the inclination to try and level your uneven wooden flooring yourself, you may be considering hiring a professional local tradesperson to do it instead.
You might not have a choice in the matter if the unevenness of your flooring is due to a foundational issue, as this will sometimes need to be assessed and corrected by a professional foundation repair company or a professional general contractor.
While costs will vary greatly depending on the laborer you use, the size of the room, and the type of flooring you have, you can generally expect to pay anywhere from $2 to $30 per square foot (or potentially even more!) for a professional to level your uneven floors for you.
It’s up to you whether you decide to hire a professional or do it yourself, but keep in mind that leveling your flooring is a big project and you’ll have to live with the results. Literally.
There is also the value it will add to your home to consider, as this could offset the cost of having your floor professionally leveled if you were to decide to sell the property in the future.
Either way, we hope we’ve helped!