How to Level a Floor

We often take it for granted that our floors are level. You may never have thought about it, but it impacts the structure and safety of your home. An uneven floor can make installing new flooring, whether that’s laminate, tiling or hardwood, incredibly difficult. It could also indicate several structural issues in your home. 

Anything to do with the structure of your home is complex, and levelling a floor is no different. Here’s a guide explaining how to level a floor and some key considerations you should make before doing so.

9 Steps to Level a Floor

1. Preparation: Clean the floor and remove furniture.
2. Crack Repair: Fill significant cracks.
3. Spot Marking: Identify uneven areas.
4. High Spot Grinding: Grind down high points.
5. Priming: Apply primer and let it dry.
6. Compound Mixing: Mix the self-levelling compound.
7. Application: Spread the compound evenly.
8. Adjustments: Fine-tune levelling as needed.
9. Drying: Allow the compound to completely dry to achieve a smooth, levelled floor

Subfloors

Your floor is not just a carpeted or tiled surface; there’s a subfloor underneath that affects the top layer. This layer can consist of concrete, plywood or Oriented Strand Board (OSB) installed directly above the floor joints. 

As the subfloor is a crucial part of your building’s strength and structure, it can significantly impact your floor above. Any instability, bumps, dips or irregularities may prevent you from installing new carpet, tiles or laminate. Thus, levelling your subfloor is a necessity.

How To Detect Uneven Floors

Detecting and measuring your uneven floors is the first step to levelling them. Though it may seem trivial, being able to identify an uneven floor can be tricky, and certainty is crucial. Here’s how you can detect two common issues: 

Room Slope

When your room slopes, it is easily detectable. Use a spirit level (the longer, the better) and lay it on the floor. Look to see whether the bubble is central. You can measure your slope by lifting the spirit level until the bubble is central and then measuring the gap between the level and the floor.

Minor Irregularities

To identify and measure minor bumps and dips, lay a long straight edge across the floor, from one wall to the other. Then walk along the edge and look for gaps between it and the floor. You can move the line across the floor and measure these gaps at various points to map out the irregularities.

Levelling Your Floor

Levelling your floor is a complex process that can quickly go wrong. Whilst measuring and detecting uneven floors is simple enough for most people to complete, you are likely to struggle to level your floor. 

Going for a professional flooring fitter is your best strategy. They will not only be able to level the floor but also diagnose the problems causing it and fix any structural issues impacting your floor to prevent future complications. You may not know how deep the problem lies. For example, sagging floors may be a result of foundation failure. Plus, a professional; will be able to do it much faster, meaning the construction will not dramatically interrupt your life.

Important Safety Considerations

When dealing with the structure of your home, it’s vital to remember that years of use can damage the elements. Make sure that you manage any load on broken flooring and timber joints, as placing heavy items in weak areas can apply extra stress and risk the structure giving way.

Preparation

Your preparation is probably more important than the actual levelling process, as failing to prepare will reduce the process’s effectiveness. There are some key steps to take to get your floor ready for levelling.

Develop a Strategy

Planning will help you save time and money when levelling your floor. You need to know how uneven your floor is and whether you need to make any structural repairs before levelling. A trained professional fitter is the best person to ensure you plan correctly.

Remove Existing Flooring

After creating your plan and removing any furniture from the room, you must remove your flooring. Whether you have laminate, carpet or tiling, rip the existing flooring and any underlay to access and level the subfloor.

Repair 

Once the existing flooring is gone and the subfloor is revealed, you’ll be able to investigate its condition. You need to fix any major damages and fill any cracks with filler.

Sand Your Subfloor

If there are dips and low spots on your floor, there will likely be high spots too. Sanding these high spots down will mean you need less self-levelling compound to create a level surface.

Clean the Subfloor

If your subfloor is covered in dust or dirt, it can prevent compounds from adhering to it. Vacuum the dust and dirt away and then mop the floor.

Apply Primer

Like cleaning your floor, primer helps a compound adhere to it. Therefore, applying a layer of primer makes the levelling process easier. 

Applying Self Levelling Compound

After completing the necessary preparation steps, you are ready to level the floor. The most popular method uses a self-levelling compound. It’s a viscous liquid made of polymers, cement and water that, as the name suggests, levels itself due to this liquid property. 

The compound comes in bags of powder that need to be combined with water. The fitter will start by blending the mixture into a creamy consistency without any lumps. Then they will pour it into one corner of the room. It will spread across the floor, fill any depressions and form a level surface. The fitter will smooth out any consistencies and then leave it to set. 

Common Problems

When you level your floor, there are some common complications that you may encounter. Investigate the structures around your floor and subfloor before beginning any construction to locate problems and adjust your strategy accordingly. If you find any of them, call a construction professional, as they require specialist knowledge to fix them.

Bowed Floor Joists

In especially old buildings, the wooden joints underneath your subfloor may have bowed due to weight and pressure. This misshapen nature may be reflected in the floor. 

Rotten Timber Joists 

If your wooden joints are damp, perhaps due to leaking pipes, it can promote rotting. When the joints rot, they weaken and risk the floor’s structural integrity. 

Failing Brickwork

Failing brickwork around the floor joints is a significant hazard that takes time and skill to mend. It can be crumbling or weak, making the joints and floor uneven.

Our Floor Screeding Services

If you discover that your floor is uneven, don’t leave it to get worse. At AB Drylining, we specialise in levelling floors with screeding, offering you professional labour and expertise at competitive prices.

Every single one of our technicians has an NVQ Level 2 Qualification and CSCS Health and Safety cards as a minimum. As a company, we are accredited by IPAF and PASMA, certifying us to deliver you the highest quality whilst ensuring safety.

If you want to learn more about how we can protect your floors, contact our specialists today. 

FAQ

How much does floor levelling cost?

Choosing a professional floor fitter is crucial for correctly levelling your floor. Their costs will vary depending on the size of your project; if you require comprehensive structural repairs, it will take longer and incur higher costs.

How can I level a concrete floor?

Typically, you use a self-levelling compound to create an even surface on your floor. It is a liquid concrete polymer compound that finds its level when spread across an uneven subfloor.

Does a subfloor need to be level?

No subfloor is truly level, but you should always aim to make yours as level as possible so that you can apply comfortable flooring.