When starting any building project, one of the most important decisions you’ll make is choosing the right material for the job. It might sound simple, but mixing up screed and concrete—or using the wrong one—can lead to costly issues later on.
At Q Mix Concrete, we regularly speak with customers who aren’t quite sure which they need. While screed and concrete are closely related, they serve very different purposes. Understanding that difference is key to getting a strong, long-lasting result.
What is Concrete?
Concrete is the backbone of most construction projects. It’s what provides the strength and stability in everything from house foundations to driveways and structural slabs.
It’s made by mixing cement, water, sand, and coarse aggregates such as gravel or crushed stone. That larger aggregate is what gives concrete its strength.
From experience, if your project needs to carry weight or deal with regular wear and tear, concrete is the material you’re looking for.
What is Screed?
Screed, on the other hand, is all about the finish.
It’s a much finer mix—usually made from cement, water, and sharp sand—and is applied on top of a concrete base. Its job is to create a smooth, level surface ready for flooring like tiles, wood, or carpet.
Think of it this way:
Concrete does the heavy lifting, while screed provides the final surface.
Screed vs Concrete – Key Differences
| Feature | Concrete | Screed |
| Purpose | Structural support | Surface finishing |
| Strength | High | Moderate |
| Aggregate Size | Up to 20mm (coarse) | Up to 4mm (fine sand) |
| Application | Foundations, slabs | Flooring top layer |
| Finish | Rough | Smooth and level |
The Real Difference Between Screed and Concrete
While both materials contain cement and water, the main differences come down to strength, texture, and purpose.
- Concrete uses coarse aggregates (up to 20mm), making it strong and durable
- Screed uses fine sand (usually up to 4mm), giving it a smooth finish
- Concrete is used for structural support
- Screed is used for levelling and finishing floors
In simple terms, concrete forms the base, and screed finishes it.
When Should You Use Each?
This is where many projects go wrong, so it’s worth getting clear:
- Use concrete for foundations, footings, driveways, and any load-bearing surface
- Use screed when you need a flat, even surface on top of concrete
Trying to use screed as a structural material won’t hold up over time, and skipping screed can leave you with uneven flooring.
Getting It Right First Time
One thing we’ve learned over the years at Q Mix Concrete is that choosing the right mix early on saves time, money, and hassle later.
Whether you’re working on a domestic renovation or a commercial build, having the correct material delivered—mixed to the right specification—makes all the difference.
If you’re unsure, it’s always better to ask before you pour.
FAQs – Screed vs Concrete
Can screed be used instead of concrete?
No, screed isn’t designed to handle structural loads. It should only be used as a finishing layer over a concrete base.
Is screed as strong as concrete?
Not quite. Concrete is much stronger and built for durability, while screed is designed for surface levelling.
How thick should the screed be laid?
In most cases, screed is laid between 25mm and 75mm, depending on the type of project.
Do you always need to screed over concrete?
Not always, but if you’re installing flooring, screed is usually needed to create a smooth, even surface.
How long do they take to dry?
Concrete starts setting within a day or two but takes around 28 days to fully cure. Screed dries more gradually—typically around 1mm per day.