The Importance Of Grinding A New Screed Before Tiling

When preparing a newly poured sand and cement screed for tiling, grinding the surface is an essential step that often gets overlooked. It’s not just an extra task; it's a critical part of ensuring the longevity and success of your tiling installation.

Why Grinding Sand and Cement Screed Is Essential

After pouring and curing a sand and cement screed, a layer known as "laitance" forms on the surface. This is a weak, dusty, and sometimes shiny layer made up of fine cement and water that rises to the top during curing. While it may look solid, it’s not suitable for tiling.

Tiling directly onto laitance can prevent adhesives from bonding properly to the screed. Over time, this can lead to significant issues like lifting tiles, poor adhesion, or cracking. To avoid these costly problems, it's important to grind the laitance away and expose the stronger, solid aggregate underneath.

Understanding Laitance and Its Risks

Laitance is deceptive—although it seems solid, it lacks structural integrity. Imagine it like a layer of dust pressed into the surface. It may hold for a while, but once tiles are installed, stresses like foot traffic, temperature changes, or water exposure can cause the bond to break. This results in tiles detaching and can be time-consuming and expensive to fix.

By removing this weak layer, you create a surface that tiling adhesives can securely grip, ensuring a lasting bond. It also gives you the opportunity to spot any surface imperfections or irregularities before tiling begins. See the image below to see the difference between a grinded and non grinded screed, you can clearly see the latiance build up.

Top - Grinded, Bottom - Non grinded.

The Grinding Process To properly prepare the sand and cement screed, the laitance layer must be ground back using a professional floor grinding machine. At Aspire Tiling, we use a Bihu grinder, which offers precision and efficiency for large areas. This high-performance tool features rotating diamond abrasives that remove laitance evenly, exposing the solid material beneath without damaging the screed’s integrity.

We always assess the floor for uneven areas or high spots before grinding. The grinding process is typically done once the screed has fully cured—usually after 7 to 10 days. It’s important not to rush this step, as grinding too early can cause unnecessary damage.

Once the grinding is complete, we vacuum the surface thoroughly to remove all fine dust and debris. The result is a clean, open-textured surface that is perfect for receiving tile adhesives. This ensures the strongest possible bond and significantly reduces the risk of tile failure.

Process of grinding a screed with the Bihui concrete floor grinder.

Additional Benefits of Proper Preparation

Grinding a new sand and cement screed doesn’t just ensure a strong bond between tile and substrate; it offers other advantages too:

• Improved tile alignment by removing surface imperfections

• Identification of low spots or cracks that may need filling before tiling

• Better coverage and adhesion of primers or self-leveling compounds (if needed)

• Increased durability and lifespan of the entire tile installation

• Faster drying of the screed, allowing moisture to evaporate more effectively

Skipping this preparation step may save time upfront, but the long-term risks are far greater. Replacing failed tiles, repairing cracked screed, or dealing with water damage can be avoided with proper preparation.

Why Choose Aspire Tiling?

At Aspire Tiling, we prioritize every detail of your tiling project—from thorough preparation to flawless finish. Based in Cardiff and serving all of South Wales, we specialize in wall and floor tiling, bathroom renovations, underfloor heating installations, and bespoke tile work. Our expert team ensures every project is completed with care, precision, and long-lasting results.

We believe in doing things the right way from the start, which is why we invest in proper preparation, including professional sand and cement screed grinding. This way, your tiled surface not only looks fantastic but stays that way for years to come.

If you’re planning a tiling project and want peace of mind that it’s built to last, get in touch with Aspire Tiling today. We’ll advise on the best preparation methods for your space and provide a quote for your full tiling installation.

📧 info@aspiretiling.co.uk

📞 0800 112 3011

📍 Cardiff & South Wales