The importance of effective surface preparation

Preparation stages are extremely important. To get the best results, the initial work should be done to put your surfaces in the best possible condition, ready for your flooring project. No matter how advanced or high-quality a coating, screed, or flooring system may be, it will only ever perform as well as the surface below allows. 

From industrial floor coatings and levelling compounds to damp-proof membranes and primers, proper surface preparation underpins durability, adhesion, and long-term performance. In this blog, we’ll explore surface preparation in construction, its importance, and the various cleaning methods and post-preparation considerations.

What is surface preparation in construction?

Surface preparation can involve a range of methods to treat a substrate so it’s suitable for products like floor coating, levelling compound, screed, or waterproofing systems (e.g. cementitious tanking slurry). The main reason for doing this is to create a clean, dry surface that's ideal for forming a strong bond. 

This could involve:

• Removing oil, grease, dust, or old coatings
• Repairing cracks or weak concrete
• Managing moisture levels
• Creating the correct surface profile or texture
• Applying primers or bonding agents

Why is surface preparation important?

Ultimately, effective surface preparation is essential because it can be the difference between a successful flooring or coating system and one that fails. If the surface isn’t ready, it can cause many issues in later stages (we’ll cover these in more detail below). Here are some reasons why surface preparation is important. 

Ensures proper adhesion

Most flooring products rely on mechanical or chemical bonding. Dust, laitance, oil, curing agents, or residual adhesives can hinder primer, coatings, or levelling compounds from bonding correctly. 

Without sufficient adhesion:

• Floor coatings may blister or delaminate
• Levelling compounds can debond or crack
• DPMs may fail to seal the substrate

A clean, well-prepared surface will allow your products like primer, epoxy coatings, and latex systems to thrive.

Improves durability and lifespan

With the correct preparation, you can potentially extend the lifespan of a flooring system and improve its durability. By removing weak surface layers and repairing defects, it allows loads to be transferred evenly through the substrate. 

This is important in circumstances such as:

• Industrial floors with traffic or impact
• Commercial environments with heavy footfall
• Areas exposed to chemicals, moisture, or thermal movement (such as commercial kitchens, plant rooms, balconies, and external loading bays)

When completed effectively, a prepared surface reduces the risk of cracking, wear, and surface breakdown over time. 

Prevents costly failures and repairs

The last thing anybody wants is to have to rectify issues further down the road, because this costs more time and money. For example, issues such as peeling coatings or hollow-sounding levellers can require removal and reinstallation.

Investing time in preparation:

• Saves material and labour costs
• Avoids delays to project schedules

A surface preparation guide

Although every project is different, the steps below provide a practical guide to preparing most concrete and screeded surfaces before installing flooring or coatings. We’ll also outline the common hurdles people come across when preparing a surface and how to tackle them.

Inspect and assess the substrate

Before any work is started, it’s crucial to assess the condition of the substrate first. Can you spot any cracks, weak areas or contamination? Is there laitance, previous coatings, or adhesive residues still on the substrate? Assessing in this way will help you to plan out your preparation method and primers, or repair products needed.

Remove contaminants and weak material

Loose or contaminated material should be removed. This could involve mechanical abrasion, grinding, shot blasting, or chemical cleaning, depending on site conditions. Some common contaminants that you’ll find on substrates include:

• Oil and grease
• Paints and curing agents
• Dust and laitance
• Old adhesives

Repair cracks, joints, and surface defects

Cracks, holes, and damaged areas should be repaired using suitable rapid-hardening or resin-based repair systems. Ignoring defects can lead to reflective cracking or failure of the finished floor. The repairs must be structurally sound, fully cured, and finished flush with the surrounding surface to maximise the likelihood of bonding to your products. 

Control moisture and apply DPMs where required

Excess moisture is a common cause of flooring failure as it affects adhesion and curing. This causes blistering, debonding, cracking and more over time, due to hydrostatic pressure beneath impermeable finishes. Moisture management is especially vital before installing things like resin floor coatings, vinyl or decorative finishes, and levelling compounds not designed for high RH.

Prime the surface correctly

Primers are always critical. In this instance, they help to regulate porosity, improve adhesion, reduce air bubbles and pinholing, and act as bonding agents between layers. There is a range of primers to choose from, including epoxy resin primers and more, so research into the most effective for your project is essential for long-term performance.

Types of surface preparation methods

There’s a variety of techniques you can use when preparing a surface, and each may work better for different substrates and site conditions. We’ve outlined some of the most commonly used methods, and we’ll look more closely at how, why, and when to use them. 

Abrasive blast cleaning

Abrasive blast cleaning uses propelled abrasive material to remove surface contaminants and create a textured profile. It’s effective for preparing concrete before resin coatings or heavy-duty systems because it creates a strong, textured surface that allows resin systems to achieve maximum mechanical adhesion. 

Best for:

• Removing laitance and old coatings
• Creating a strong mechanical key
• Industrial flooring applications

Wet abrasive blast cleaning

This is a combination of water and abrasive blasting to reduce dust and control airborne particles. It yields results similar to dry blasting but requires drying time. So why use this over non-wet abrasive blasting? Well, this may be a better choice in enclosed areas because it significantly reduces airborne dust.

Best for:

• Dust-sensitive environments (e.g., hospitals, food production areas)
• Heavily contaminated surfaces (e.g., engineering workshops, vehicle maintenance bays)
• External or well-ventilated areas (e.g., loading yards, car parks)

Hand and power tool cleaning

Hand and power tools such as grinders and scabblers are often used for small areas or repairs. These tools work by mechanically abrading the surface: grinders use rotating diamond segments to remove thin layers of material and smooth uneven spots, while scabblers use percussive action to break away weak or damaged concrete. The result is a cleaned, lightly textured surface that can improve adhesion for primers, levelling compounds, or coatings. Although they’re less aggressive than other methods, they can be effective when used in the right way.

Best for:

• Edge preparation
• Small repairs (e.g. localised crack repairs, patching blowholes, or preparing infill areas after removing fixings)
• Areas with limited access (e.g. corners, door thresholds, around columns)

Acid etching

When acid etching, you apply acid solutions to remove laitance and open the surface. It’s crucial that it’s carefully controlled and neutralised afterwards, because any residue left on the surface can react with the substrate, weaken the concrete, prevent proper adhesion, and even cause long-term damage. 

Best for:

• Light laitance removal
• Smaller internal areas (e.g., garages, retail units)

High-pressure water jet

This is a great way to remove any loose material at the start. Using a pressurised water jet to spray the surface, it can clean effectively without introducing dust. It may not be the only step in your surface preparation, but it’s certainly a great starter.

Best for:

• Removing dirt and loose material
• External slabs and concrete
• Situations where dust must be minimal (e.g., refurbishment projects in occupied premises, schools)

Flame cleaning

Flame cleaning uses intense heat to remove oil, grease, and coatings. It works by passing a multi-flame torch over a surface at different speeds and distances, creating temperatures ranging from 500°C to 700°C and above. This causes impurities to combust and helps remove contaminants such as scale and rust. It’s a specialist technique that requires trained operatives and strict safety controls.

Best for:

• Heavy industrial contamination
• Steel or specialist concrete applications

Solvent cleaning

Solvent cleaning involves applying chemical solvents to the substrate to break down, dissolve, and remove contaminants such as oil and grease from the surface. Typically, you’d apply the solvent by wiping, spraying, or scrubbing to penetrate the oils and grease so they can be easily removed from the surface. 

It works by chemically dissolving oils and greases, which water can’t do. However, solvent cleaning does not remove the contaminated concrete itself; it only mobilises the contaminants, which is why this method should be followed by mechanical preparation such as abrasive blasting.

Best for:

• Degreasing small areas
• Spot treatment prior to mechanical prep

What to consider after cleaning

When cleaning and preparation are complete, it’s worth going through a brief checklist to make sure the surface is ready for the products you want to apply. This involves looking at surface dryness, cleanliness, surface profile, and more.

• Surface dryness: Ensure moisture levels are at an acceptable level for your products
• Surface strength: Make sure the substrate is sound and free from weak or friable areas
• Cleanliness: Check that there’s no residual dust, debris, or cleaning agents
• Surface profile: Confirm the texture is suitable for the product you’re applying
• Priming requirements: Apply the correct primer at the recommended coverage rate
• Timing: Follow the minimum and maximum overcoating times between preparation, priming, and installation

Get the right products for effective surface preparation

Effective surface preparation in construction doesn’t stop at cleaning and repairs. Choosing the right products is just as important to the long-term success of any flooring or coating system. From primers and moisture control solutions to levelling compounds and heavy-duty floor finishes, using products that are designed to work with properly prepared substrates helps reduce risk on site and ensures consistent, reliable results.

Our range of flooring products has been carefully selected to support every stage of the preparation and installation process, whether you’re working on commercial, industrial, or domestic projects. If you need guidance on product selection, compatibility, or surface preparation requirements, our team is on hand to help. Simply contact us today.