Ratgeber: Betonplatten flexen. Schneiden mit dem Winkelschleifer Bannerbild

Cutting concrete slabs with Flex - everything you need to know

Cutting concrete slabs with an angle grinder is a cheap and effective method.

Difficulty: Easy | Costs from €14 | Workload per cut approx. 5 - 10 minutes

Learn how to cost-effectively and efficiently cut concrete slabs with an angle grinder.

Whether for sidewalks, terraces, driveways or as a foundation for garden houses and carports, concrete slabs can be used in many different ways and often require individual adjustment.

Table of contents

Cutting concrete slabs for a carport

As a rule, the concrete slabs have to be cut to size at one point or another. If you didn't pay attention to exact dimensions during your planning that happen to match the total area, you have to get them to measure.

Not everyone has professional stone saws at hand and has to resort to the angle grinder (flex).

1. What tools and machines are best for cutting concrete slabs?

  1. Cutting disc : Choose a flex (angle grinder) with a matching concrete diamond disc. The diameter required for a flex is 125 mm.

  2. protective clothing: Wear safety goggles, hearing protection, and ideally a respirator.

  1. Pen or scribe: Mark the desired cut point with a pen or scribe. Be sure to mark a straight cutting edge.

  2. Water: Use water when flexing concrete slabs. The water binds the dust and ensures additional cooling of the concrete cutting disc.

Guide banner image Cutting concrete - The most popular methods Tools and machines

2. How do I cut concrete slabs with the Flex?

Cutting concrete slabs with Flex and concrete diamond cutting disc

Cutting concrete slabs with an angle grinder is not particularly difficult. We will help you with this step-by-step guide.

  1. Mark the cutting line: Use a pencil or scriber to mark the cutting line on the concrete slab.

    Craftsman marking the cut edge of a concrete slab


  2. Lay the concrete slab on a flat surface: Lay the concrete slab on a flat surface to prevent it from slipping while flexing. If possible, you should let the concrete slab overhang slightly. This prevents you from cutting into the ground.

  3. Wear protective clothing: Protective equipment is extremely useful when cutting any material. It protects you from serious injury in an emergency.

    Wearing protective equipment when cutting concrete is mandatory. Handyman with respirator, goggles, safety shoes

  4. Choose the right concrete cutting disc : Choose a suitable concrete diamond disc for your angle grinder (flex) to make clean and precise cuts in concrete slabs.

    Concrete diamond cutting disc 125 mm for cutting concrete slabs with the Flex


  5. Cut slowly and with control: Cut slowly and with control along the marked cutting line. Don't put too much pressure on the concrete slab. If your blade is not deep enough to make a full cut, you can turn the slab over and repeat the steps.

3. Can I cut round concrete slabs? Only possible with the Flex

A curve is cut in a concrete slab

Our craftsmanship experience: Precise transfer of dimensions is crucial for cutting curves.

Use a simple compass made from string and a stick or nail to scribble the curve.

Hold the flex at a slight angle to allow the diamond blade a larger cutting radius.

Our tip for circular cutting: Hold the angle grinder at a slight angle to enable the diamond cutting disc to cut a larger radius.

Concrete cutting disc in use when bending concrete slabs

4. Alternative to cutting the concrete slab with the flex - break concrete slab

If you don't have a cutting disc handy, you can try breaking your concrete slab. Please be aware that this method does not always lead to precise and clean results.

  1. Mark a line where the plate should be broken.

  2. Always drill a hole 3cm apart

  3. Strike between the holes with a hammer and chisel. Thus, a breaking point should gradually develop.

Frequently asked questions about cutting concrete slabs with Flex:

1. Can I cut concrete slabs with a conventional saw?

It is not recommended to cut concrete slabs with a conventional saw as these saws are not suitable for concrete slabs. Use a flex with a concrete diamond blade instead.

2. Can I have concrete slabs cut ?

You can have your concrete slabs cut at a hardware store of your choice. Many markets such as OBI, Hornbach or Bauhaus have a cutting service. Additional costs may apply. You can also hire a craftsman to cut concrete slabs.

3. How deep can I cut concrete slabs with a Flex?

You can usually cut concrete slabs to a depth of around 50mm. If you need deeper cuts, consider using a concrete cutter or cutting table.

4. How can I prevent the concrete slab from breaking when cutting?

There is no 100% guarantee that will protect you from a concrete slab breaking at an unwanted point during the cutting process. If you are particularly good at using the flex, you can cut the interface along the surface to create a predetermined breaking point.

Create a predetermined breaking point along the cutting edge with the flex and a diamond disc

Conclusion - The Flex is a good machine to cut concrete slabs

Cutting concrete slabs with a Flex can be a simple and effective way to cut concrete slabs to size. Choose the right concrete diamond blade and wear protective clothing. If you observe the right techniques and safety precautions, nothing should stand in the way of the perfect result.

Back to blog

1 comment

In diesem bericht(Punkt 2)das Bild mit trennscheibe ohne scheibenschutz ist vollkommen ungeeignet.es sei den,der Handwerker hat mehr als 10 Finger und 2 hände

Roland Lejeune

Leave a comment

Please note, comments need to be approved before they are published.

  • Bild von Jürgen Kleis Werkzeuge Experte - Tipps und Tricks rund um das Thema Handwerken und Heimwerken

    Jürgen Kleis

    "With my many years of experience in the tool industry, I can give you helpful tips and tricks for DIY and handicrafts".

    To the author page 
  • Other helpful platforms

    I try to give the community at all available levels tips for building a house, renovating or gardening.