Level Up Your Construction Game! How to Level a Floor So It’s Safe to Build On
Raise your hand if you can spot a bad concrete job from a kilometre away. (Hands up!)
A botched concrete job can spell disaster for any building.
One of the most important things you can do as a concreter is to make sure your concrete pads are level. This ensures that your work will last for many years and that the flooring on top of it will look and feel beautiful.
Here are some of our best tips for how to level a floor so it’s safe to build on.
Flat vs Level: What’s the Difference?
The word “level” gets thrown around a lot. But it means different things to different people.
A flat floor is one that’s uniformly flat throughout. You need a flat floor to lay most types of flooring. Just because a floor is flat, it doesn’t mean it’s level.
A level floor is parallel to the horizon. It’s a function of gravity and not just the walls around it. For the best turnout in your building project, you want the floors as flat and level as possible.
Flat versus level is an error that lots of tradesmen make if they aren’t careful. That’s why you sometimes end up fixing someone’s handiwork later on.
Why Level Is Best
Levelling has to do with gravity. You need to make sure everything is parallel or perpendicular to the horizon.
Why does this matter? Because gravity is the biggest force that the new structure will deal with throughout its life.
Gravity pushes against the building, causing weaknesses to occur. The less level the building, the more weaknesses are exposed to the forces of gravity and the more likely you are to get sags and cracks.
The Pouring Process: Tips and Tools to Ensure Success
If you want your subfloor to last for many years, you need to start at the bottom. Make sure that the underlying concrete pad is level when it’s poured. Let’s take a look at the best way to do that.
First, prep the ground beneath the new concrete pad to get it as straight and level as possible. Make sure you’ve filled with sand or gravel and compacted the ground so that it’s flat and sturdy.
How you prepare the ground depends on the type of soil you’re dealing with. Follow the building codes in your area. Proper preparation prevents cracks from forming under the concrete foundation.
Then mix your concrete. When working on a small project, mix the concrete in small batches in a wheelbarrow. With larger projects, you’ll need a mixer to keep the concrete at the right wetness level.
Measure and set up perimeter boards based on how you want the concrete to flow. If you’re dealing with a patio or outdoor pad, you may want the boards to slope slightly to allow for water drainage. For floors inside a building, you’ll want them to be as close to level as possible.
Check the corners of all your form boards with a 122 cm level. You want a long level to ensure that the boards remain level further into the corner.
After you’ve raked the concrete into place, use a straight piece of lumber to work as a screed. Remember, it must be straight. So check this board with your level before using it.
Once you’ve pulled the screed across the entire area, you should have a straight and level surface to build on after it dries.
Levelling an Existing Floor: Tips to Fix What’s Wrong
As a tradie, you know the importance of doing a job right the first time. But sometimes, the job doesn’t go as well as you’ve planned.
Also, floors shift and buildings settle with age. If you’re working with an older building, you may come across issues with unlevel floors. We’ve got a few tips for how to fix a floor that’s currently not level.
Think about the type of flooring you plan to put on top of the subfloor. If it’s carpet or a floating, vinyl, plank-style flooring, then it’s fine if the floor isn’t perfectly level. Most people won’t notice a small variation in level change as long as it’s kept under a half centimeter or so.
Unless you’re doing subfloor for a pool hall, you can get away with a little slope. The best way to level an existing floor is to use a high-quality concrete leveller product. These products are similar to concrete, but they’re more liquid, so they spread easier.
Before you use the leveller, prep the floor by removing debris from cracked concrete or flaked paint. Clean the floor with an industrial concrete cleaner. Then sandblast it to create a rough surface for the leveller to stick to.
Use a concrete primer for the best results. Once the primer dries, apply the leveller compound and smooth it out along the floor with a long squeegee. Gravity does the bulk of the work here, filling in gaps and low spots as necessary.
Give this product a few hours to dry before walking on it. Allow at least a day of dry time before you try to lay flooring on top of it. Because leveller products use gravity, they’ll ensure that your new floor is as straight and level as possible.
How to Level a Floor the Right Way
Nobody enjoys an uneven floor. These are a few of our favorites tips for how to level a floor the right way.
Before you pour your concrete, make sure the ground is backfilled and compacted to ensure a strong start. Level your perimeter boards as you go by using a long level spread between boards. Then use a flat piece of lumber to pull the concrete between the boards in an even way.
When fixing an existing floor, use a high-quality concrete leveller compound. Prep the floor by cleaning and sandblasting. Then use a primer to ensure the best surface for the leveller to adhere to.
Check out the awesome variety of concrete products we offer at Canberra Diamond Blade. We’re here to make sure you’ve got the best tools for the job, all in one spot!