Screeding for Laminate Flooring: Why a Level Subfloor Matters

Screeding may be necessary before laminate flooring installation when the subfloor has dips or uneven areas. From our installation experience, an uneven floor can make laminate bounce, creak and pull apart. Over time, the movement can also damage the locking joints.

At Laminate Floor World, we always check the surface underneath the flooring before installation. This step is just as important as choosing the right laminate.

Modern laminate flooring has changed considerably over the years. Manufacturers now use stronger and more advanced locking systems. Many newer ranges also have water-resistant joints. However, these systems need a flat and stable surface underneath them.

Our golden rule is simple: a good laminate flooring installation starts with an even subfloor. Poor preparation can affect the entire installation.

Correct screeding creates a flat and stable subfloor before laminate flooring installation, helping to reduce movement, creaking and stress on the locking joints.

What Is Screeding for Laminate Flooring?

Screeding helps us correct dips and uneven areas before we install laminate flooring. It creates a smoother and flatter surface for the laminate to rest on.

The goal is not always to remove every slope from the building.

For example, an existing floor may slope from one side of a room to another. Normal screeding may not remove that entire slope. Instead, we focus on dips and uneven areas that could make the laminate move or bounce.

We want the locking system to rest on a flat and stable surface. When the boards have proper support and do not bounce, we have a much better foundation for the installation.

How Do We Know When a Floor Needs Screeding?

Some dips are easy to see. Others only become obvious when we test the floor.

One method we use is very simple. We place laminate planks with underlay over the problem area and show the customer what will happen.

If a plank moves or bounces over a dip, the customer can see the problem before installation starts.

This demonstration also helps explain why we recommend screeding. We prefer showing customers the problem instead of simply adding another item to their quotation.

Why Did My Old Laminate Last Without Screeding?

Customers ask us this question regularly.

Someone may remove an old 8mm laminate floor that lasted for 15 or even 20 years. Naturally, they want to know why the new floor suddenly needs screeding.

The answer is that laminate flooring has changed.

Modern water-resistant laminate uses more advanced locking systems. These joints fit tightly together and help stop surface water from passing through the joins.

However, the locking system still needs support from underneath.

If the subfloor has dips, the laminate can flex each time someone walks over it. That repeated movement can cause noise and put pressure on the locking joints.

Therefore, an old laminate floor lasting for many years does not automatically mean the same subfloor is suitable for a modern laminate product.

Flooring products continue to change as manufacturers develop new designs and technology. During our Decorex Sandton visit, we also saw how flooring ranges and designs continue to develop.

Can Underlay Fix an Uneven Subfloor?

No. Underlay cannot correct an uneven subfloor.

This is a common misunderstanding.

Underlay follows the shape of the floor underneath it. It also compresses as people walk across the laminate.

For the first few months, the flooring may appear fine. However, the underlay can compress over time. Existing dips may then become more noticeable.

The laminate can start moving up and down when people walk over those areas.

Different types of underlay still offer useful benefits. For example, rubber underlay can reduce noise and create a better underfoot feel. However, neither standard underlay nor rubber underlay can replace proper floor preparation.

If the concrete is uneven, we need to correct the concrete.

What Happens When Laminate Is Installed Over an Uneven Floor?

We have inspected many flooring problems over the years. When the subfloor is uneven, we commonly find:

• Creaking when people walk across the floor
• Movement or bouncing underneath the boards
• Laminate joints pulling apart
• Damage to the locking system
• Broken locking joints

These problems can develop slowly.

Every time someone walks over an unsupported area, the board moves. That movement puts pressure on the locking joint. Repeating this thousands of times can eventually damage the joint.

Our guide explaining why laminate flooring creaks looks at this problem in more detail.

Why Modern Water-Resistant Laminate Needs Good Preparation

Many modern water-resistant laminate floors use tighter locking systems than older laminate products.

The joints form an important part of the floor’s protection against surface spills. Therefore, they need proper support underneath them.

An uneven subfloor can allow the boards to flex. This movement places extra pressure on the locking system.

That is why we take subfloor preparation seriously when installing modern water-resistant laminate.

Customers should also remember that water-resistant laminate does not make the complete floor waterproof. Water can still enter underneath the boards through leaks, doors, walls and other areas.

Our laminate flooring water damage guide explains what we have found when lifting floors after leaks and moisture problems.

How We Prepare a Subfloor Before Screeding

Good screeding starts with good preparation.

We first inspect the existing surface. The preparation method then depends on what we find.

When we work over tiles, old slate or concrete, we commonly use an ITE slurry system. The slurry helps the screed bond to the existing surface.

Old parquet flooring presents another challenge. After removing parquet blocks, old bitumen glue often remains on the concrete.

We need to prepare this surface correctly before applying the screed. Simply covering the old glue without the correct preparation can affect the result.

How Long Does Self-Levelling Screed Take to Dry?

Drying time depends on several factors. These include the product, screed thickness, weather and conditions inside the property.

In our installations, ITE self-levelling screed commonly needs around one to two days to dry. Weather can change this time.

However, we never recommend judging screed only by looking at the surface.

The top can look dry and feel firm enough to walk on while moisture remains deeper inside.

This is why moisture testing matters before laminate installation.

A Floor Can Look Dry and Still Contain Moisture

We experienced this problem on a real installation.

After screeding the floor, the customer wanted us to install the laminate the following day. The surface looked dry and we could walk on it.

However, our moisture test showed that the screed still contained moisture underneath.

The customer insisted on continuing with the installation. Months later, a large amount of moisture had collected underneath the laminate.

This case taught an important lesson. A dry-looking surface does not always mean the complete screed has dried.

Waiting a little longer can prevent a much larger flooring problem later.

What Happens if a Customer Refuses Screeding?

We first explain the problem and, where possible, show the customer the movement.

If we recommend screeding and the customer refuses it, we ask them to sign a waiver. The document confirms that they chose to continue against our recommendation and accept that the relevant flooring guarantee will not apply.

Many customers change their minds once they understand the risk. They often decide to complete the screeding rather than risk problems with their new floor.

The waiver also protects both parties. It records the condition of the subfloor before installation and makes our recommendation clear.

What if Carpet Is Covering the Subfloor?

Carpet can hide the condition of the concrete underneath it.

As a result, we cannot always confirm whether screeding will be necessary during the first quotation.

We explain this to the customer before installation. Where necessary, we quote the screeding separately and tell them that additional preparation charges may apply once we remove the carpet.

From our experience, it can be roughly a 50/50 situation. Some subfloors are flat enough, while others need additional preparation.

Discussing this possibility beforehand prevents unexpected costs on installation day.

Does Screeding Make a Sloping Floor Perfectly Level?

Not always.

A sloping floor and an uneven floor are not exactly the same problem.

If an existing floor slopes significantly across a room, normal flooring preparation may not remove the complete slope.

Our main goal is to create a smooth and sufficiently flat surface for the laminate locking system.

We do not want the boards bouncing over dips. Once the laminate has stable support underneath it, the locking joints can work as intended.

Correcting a major structural slope may require more extensive building work.

Can You Screed Over Tiles?

Yes, in many cases we can screed over tiles. However, we first need to check that the existing surface is stable and suitable.

We commonly use a bonding slurry when preparing tiles or old slate for screeding. This helps the new screed bond to the existing floor.

We still need to deal with problems such as loose tiles or moisture before continuing.

Every property is different, so we assess the existing floor before deciding how to prepare it.

What About Old Parquet Flooring?

We often find parquet flooring in older homes.

Removing the wooden blocks can leave old bitumen adhesive stuck to the concrete. The remaining glue creates a surface that needs further preparation.

We use the correct bonding process before screeding these areas where required.

This gives the new laminate a much better foundation.

Is Screeding Just an Extra Flooring Charge?

We understand why customers sometimes ask this question. Screeding adds to the project cost, and customers may not have included it in their original budget.

However, selling someone quality laminate and installing it over a poor subfloor does not make sense.

We aim for quality workmanship that lasts. Proper preparation forms part of that workmanship.

When a floor needs screeding, we explain the reason and show the customer the problem where possible. They can then make an informed decision.

This is also why customers should not compare flooring quotations using only the price per square metre. Subfloor condition can affect the final installation cost.

Our laminate flooring prices guide explains other costs to consider when planning a flooring project.

Laminate or Vinyl? Subfloor Preparation Matters for Both

Subfloor preparation also matters with other types of flooring.

Choosing vinyl instead of laminate does not automatically solve an uneven floor. Each flooring type has its own installation needs.

If you are deciding between the two, read our practical comparison of vinyl or laminate floors.

Choosing Quality Laminate Flooring

Good preparation should go together with a good flooring product.

Before choosing laminate, consider its thickness, AC rating, locking system, board construction and water resistance.

Our article about AGT Natura laminate floors provides an example of a laminate range customers can consider when comparing designs and specifications.

You can also browse our main laminate flooring range and buying guide to compare more options.

Professional Laminate Flooring Installation

A successful installation depends on more than the laminate itself.

We assess the existing floor first. Next, we correct uneven areas where necessary and allow preparation products enough time to dry. Finally, we install the underlay and laminate correctly.

Our professional flooring installation service covers the preparation and installation process.

Even expensive laminate can perform poorly when the foundation underneath it is wrong.

Frequently Asked Questions About Screeding for Laminate Flooring

Does laminate flooring always need screeding?

No. We only recommend screeding when the existing subfloor needs correction. A flat, stable and dry subfloor may not need additional screeding.

Can thick underlay replace screeding?

No. Underlay follows the shape of the floor and compresses under foot traffic. It can improve sound and underfoot feel, but it cannot correct significant dips.

Can an uneven floor make laminate creak?

Yes. We regularly find movement over uneven areas when investigating creaking laminate. The boards can flex over dips as people walk across them.

Can an uneven subfloor break laminate joints?

Yes. Repeated movement can place pressure on the locking system. We have seen joints break and pull apart because the boards did not have enough support underneath them.

How long should screed dry before installing laminate?

Drying time depends on the product, thickness, weather and site conditions. ITE self-levelling screed commonly takes around one to two days in suitable conditions. We still check the floor rather than relying only on time or appearance.

Can laminate flooring go over tiles?

Yes, depending on the condition of the tiles and the floor level. We assess the surface first and prepare it correctly before installing laminate.

What happens if I refuse screeding?

If we recommend screeding and a customer decides not to do it, we ask the customer to sign a waiver. This confirms that they chose to continue against our recommendation and understand how that decision affects the flooring guarantee.

The Golden Rule for a Good Laminate Flooring Installation

After years of installing and inspecting laminate floors, our view is simple: the foundation matters just as much as the flooring on top of it.

Quality laminate, a strong locking system and good underlay cannot correct poor preparation underneath the floor.

Correct uneven areas before installation. Allow wet screed enough time to dry. Prepare old surfaces correctly before covering them.

These basic steps give the laminate locking system stable support and help the finished floor perform as intended.