The simplest way to make a concrete worktop
Cast-In-Place Concrete Mix
Every kitchen is different — our free kit builder works out exactly what you need and adds it to your cart in one click.
Build My Complete Kit →Takes 2 minutes · Calculates everything · Adds it all to cart
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A Kitchen That Looks Like No One Else's
Cast-In-Place concrete isn't just a worktop material. It's a surface you designed, mixed, and made yourself — and that shows in a way no off-the-shelf option ever could.
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A worktop nobody else hasNo two pours are identical. The colour, the texture, the character — it's yours.
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A seamless surface with no joints or grout linesPoured in one continuous slab. Something tiled or fitted surfaces simply can't replicate.
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The satisfaction of having made it yourselfYou'll know exactly what went into it — because you mixed it, poured it, and sealed it.
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A surface that starts conversationsGuests notice handmade things. Concrete has a presence that laminate and stone never quite manage.
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A durable finish built to lastProperly sealed concrete is heat-tolerant, water-resistant, and gets better with age.
How It Works
From Mix to Worktop in a Weekend
From a flat pack kitchen to a concrete worktop — here's the process from start to finish.
Measure your worktop area, mark out any openings (sink, hob), and use our free material calculator to get your exact quantities.
Construct a mould from melamine-faced board on top of your existing substrate. Apply Universal Primer, allow to dry, then coat with Mould Release Agent.
Just add water. The self-levelling mix flows into every corner — pour into the mould and trowel flat. No vibration, no specialist tools needed.
Leave for a minimum of 24 hours before removing the mould. The concrete continues to gain strength over the following days.
Fill any pinholes with colour-matched Smoothing Paste, sand back once dry, then apply Concrete Lab Sealer in 3 coats for a stain-resistant matt or satin finish.
Watch before you buy
See the full process — mix to finished worktop
Everything that happens between opening the bag and sealing the surface. No surprises, no gaps — just the complete process start to finish.
Why Concrete Lab
Not All Concrete Mixes Are the Same
You can buy concrete mix from a builders merchant. Here's why thousands of customers choose ours instead.
Watch what others have made
Customer Projects
Made by people like you
Every review below is from a real DIY project - kitchens, hearths, outdoor countertops and more.
FAQs
Frequently Asked Questions
One bag of Cast-In-Place Mix covers approximately 0.34 m² at a 30mm core thickness. Measure your total worktop surface area (length × depth in metres), then divide by 0.34 to get the number of bags. We recommend adding 10% for wastage. Use our MATERIALS CALCULATOR for a precise figure including all companion products.
Cast-In-Place concrete is poured directly into a mould built on your worktop surface - giving you a seamless, monolithic slab with no joints. Precast is cast in a workshop or garage and then fitted. Cast-In-Place is ideal if you want no visible seams and are comfortable working in your kitchen space.
Our Cast-In-Place Mix is designed for confident DIYers. It comes with full step-by-step instructions, and our team is on hand for support. If you're comfortable with basic woodwork (mould-making) and following a process carefully, it's very achievable. Many of our customers complete their first pour without any prior concrete experience.
We recommend a core thickness of 30mm for Cast-In-Place worktops. The downstand / shuttered edge can be thicker - typically the full visible edge depth. Thinner than 30mm is not recommended as it reduces strength and increases the risk of cracking.
Allow a minimum of 24 hours before removing the mould - longer in cold conditions. The concrete will continue to cure and gain strength over the following 28 days. Avoid placing heavy loads or hot items on the surface during this period. Always seal before use.
Yes - sealing is essential. Concrete is porous and will stain without protection. We recommend our Concrete Lab Sealer applied in 3 coats (matt or satin finish). Do not use the worktop until sealing is complete and fully cured.
The Cast-In-Place Mix is formulated specifically for worktops. For floors, walls, or bathroom surfaces, we recommend our range of MICROCEMENT for this.
What's Included
What You'll Need
The Cast-In-Place Mix is the foundation of your project. You'll also need these companion products to complete it.
Not sure how many bags you need? Use our material calculator above.
Which Method Is Right For You?
Cast-In-Place vs Precast
Both methods produce a beautiful concrete worktop. The right choice depends on your space, your setup, and how you like to work.
| Precast (GFRC) | Cast-In-Place | |
|---|---|---|
| No visible joins or seams | ✗ | ✓ |
| Workshop or off-site space needed | ✓ | ✗ |
| Cast in your own kitchen | ✗ | ✓ |
| Suitable for awkward layouts | Depends | ✓ |
| Can be made in sections | ✓ | ✗ |
| Core thickness | 20–30mm | 30mm |
| Colour matched to 5 options | ✓ | ✓ |
| Sealer required | ✓ | ✓ |
| Typical pour time | Full day | Full day |
| De-mould time | 24 hrs | 24 hrs |