Polished Concrete Flooring
for Your House Extension in Cardiff

Strong, seamless and clean — the perfect floor to connect new and existing spaces in your Cardiff home.

Expertise You Can Trust

We’ve been polishing concrete for over 20 years across Cardiff, with the prep, grind, and finish done right every single time.

Perfect for Extensions

Whether it’s a kitchen, open-plan space, or dining area, polished concrete helps tie your new layout together naturally and cleanly.

Custom Finish Options

Go natural or add colour — choose a finish that matches the tone of your home. From satin to high gloss, we’ll get the sheen just right.

Can I Have a Polished Concrete Floor on Piles or Suspended Flooring?

Yes — but it requires the right structure and planning. Here’s what you need to know if your extension isn’t built on a traditional slab:

🧱 Yes, It's Possible

Polished concrete can be installed over piled or suspended floors — as long as the base is designed to stay solid and minimise movement.

🔩 What Are Piles?

Piles are deep structural supports used when soil conditions are too weak for a standard slab. The floor rests on beams instead of direct ground contact.

🏗 What Is Suspended Flooring?

Suspended floors are raised above ground level using steel, block, or timber systems — often found in extensions and retrofit builds.

🧰 Reinforced Slab Option

A reinforced slab spanning across structural supports helps create a strong, rigid platform that can handle polishing without cracking.

🧱 Screed Over Base Option

Another method is laying a polished screed on top of a precast concrete deck or well-supported timber system, using mesh to prevent cracks.

⚠️ Movement Control is Key

Cracking occurs when the floor moves too much — so the base must be engineered to carry the load of the concrete without shifting over time.

Polished Concrete in Extensions: FAQs

Will polished concrete blend in with the rest of my home?

That depends on the look you’re going for and how the rest of your home is styled. Polished concrete has a clean, solid finish that works well alongside tiles, wood, or carpet — especially if you choose a tone or sheen that complements them. In open-plan layouts, the floor helps bounce light around, making the space feel larger. If you’re joining old and new slabs, we can help blend them with stains or finish options that soften the transition.

How thick does the concrete need to be for polishing?

For polished concrete to hold up well, the slab should be at least 75mm thick — though 100mm is ideal for regular use. This adds strength and helps prevent cracking. If you’re including underfloor heating, 100–125mm gives enough depth to fully cover the system and ensure even heat distribution. Getting the right mix and aggregate at the pour stage also makes a big difference when it comes time to polish.

Will There Be a Height Difference Between the Extension and My Existing Floors?

It depends on how your extension is constructed and what flooring exists in the rest of your home. Here’s what determines the final floor level:

  1. 1. Matching the Subfloor Height

    If the new concrete slab is poured to match the level of your existing subfloor, then the finished polished floor should line up cleanly.

  2. 2. Replacing Old Flooring

    If you’re replacing something like tile, vinyl, or wood with polished concrete, there may be a slight change depending on the thickness of the original material and adhesive layers.

  3. 3. Timber vs Concrete Base

    Homes with timber flooring may sit higher than concrete extensions. In this case, a small transition strip or step can be installed to make the change clean and safe.

  4. 4. Planning for Seamless Transitions

    We always check levels during site prep and advise the best approach — whether that means adjusting floor build-up, using thresholds, or planning the pour for a flush finish.

If you live within the Cardiff area and are interested in concrete polishing or concrete pouring for an residential space, get in touch now as all consultations are free and warmly encouraged; we very much look forward to hearing from you. Feel free to contact us on the form below and we will get back to you. Alternatively call or text us on +44 7957 361692