How To Cut A Trench In A Concrete Slab

How To Cut A Trench In A Concrete Slab
  • Author: Amanda Arnold
  • Posted On: July 14, 2022
  • Updated On: August 21, 2023

Cutting a trench through a concrete slab may seem difficult and intimidating, even if you may have good reasons for doing so. But much like any concrete cutting project, cutting a trench in a slab requires the necessary tools and safety measures.

Here are the measures you may take to help you with this project, whether you’re trying to install new plumbing, fix a drainage system, or do any other operation that requires you to cut a channel or trench in your concrete slab.

Please read our article below if you want more information about this.

Collect Required Materials And Tools

You may require specific tools to cut a trench in a concrete slab, depending on the scope of your project. Abrasive blades might also be effective, but since they tend to wear out rapidly, you might need to replace them more than once. Much more dependable are diamond blades.

The commonly needed supplies for this project are

  • Circular saw
  • Duct tape
  • Plastic wrapping
  • Shovel
  • Hammer
  • Tape measure
  • Pencil
  • Jackhammer

Mark The Concrete Area For cutting

It would help if you first inspected the area where the trench drain or channel will be cut before preparing the necessary materials and design. If possible, get hold of the area’s mechanical blueprints.

Check for plumbing and electrical lines beneath the concrete slab, especially if there is radiant in-floor heating, as severing the coils by accident will completely wreck the system. It damages people’s health when concrete-cutting jobs are excessively dusty. Use duct tape and plastic sheeting to close up the area before cutting if the work is being done indoors.

One of the best strategies to manage dust is frequently used as this. Additionally, doing this will help prevent the surrounding area from being dusty.

Use The Right Equipment For The Right Step

Based on the thickness of your concrete, choose the best saw that will complete the task easily and successfully. The steel reinforcement in residential concrete floors is frequently thick and takes the form of steel mesh and steel rebar.

A diamond-blade saw is the best tool for cutting concrete flooring in residential buildings. If you intend to use this equipment once, you can rent it from rental facilities close to your site rather than purchasing it. A small sledgehammer and a shovel with a narrow blade should also be prepared.

Clear out All Obstructions From Concrete

Ensure that there are no obstacles in the way of the concrete slab. If the concrete includes paint or other marks, you don’t need to remove them unless they make it difficult to see the cutting lines. Mark the trench after measuring that you will be cut after clearing the slab.

To do this, chalk is frequently utilized. Make careful you use the thickest, boldest lines you can. To minimize the airborne dust in your region, it is also advised to perform the task using a wet saw. Wet cutting includes adding water to the mixture, which significantly lowers the amount of dust.

Wear Protective Clothing

Ensure you have protective and safety apparel while performing the task because you will be working with dust and using powerful, noisy, and sharp tools like the wet saw and sledgehammer.

Prepare hearing protection, gloves, steel-toe boots, safety glasses, filtration masks and hearing protection.

Measure The Length For The Cut On The Concrete

Measure the trench’s required length and width using a tape measure. Then, sketch each one with a pencil or piece of chalk the perimeter of the trench you are about to dig. To make the mark as thick and prominent as possible while using chalk, it is preferable to strike the lines repeatedly.

This will make it simpler for you to recognize the mark. Make your setup as straightforward as possible while cutting a trench with drain lines. When possible, steer clear of abrupt bends, twists, and turns to lessen the likelihood of blockage.

Create The First Cut

It is time to start the task, so prepare your tools and put on your safety gear. Make a guide cut first; do not continue by already deeply cutting the concrete. Because concrete fragments could fly and harm your circular saw, this could be harmful. Adjust the depth of your saw blade to cut only about half an inch deep.

You can evaluate the concrete’s hardness by cutting a shallow line, which will help you appropriately set the saw’s blade tension. When you first cut a shallow line, manipulating your saw will be simpler.

It would help if you only did this for a short period since the blade can quickly become heated from contact with the concrete.

Go For Deep Concrete Cut

Rotate the depth handle to lower the sharpness of the blade as necessary, and cut the concrete according to your guide cut.  To cut the second edge, raise the blade and then drag the saw back to the end of the trench as you did with the first edge.

Break Concrete Strips With A Sledgehammer

After cutting the concrete strip, carefully break it into pieces using a sledgehammer. Then, remove the concrete pieces to reveal the sand or dirt beneath your concrete slab.

By excavating the remaining trench, remove the sand or soil. You can also use a jackhammer, which is better for bigger operations but costs more than a sledgehammer.


Always check that the diamond blades you use for cutting are appropriate for the saw you are using and the material you are cutting through. Also, remember that different blades are used for dry and wet cutting.

Following these instructions will be much simpler and more professional to use a road saw trencher cut concrete or asphalt trenches. This tutorial should help you learn how to dig a trench in concrete.

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Author: Amanda Arnold

Amanda has been working with ConstructionHow since 2021. Her experience spans over 5 years in the creative niche such as home decor and trends, landscaping, renovations, and custom architectural values. As a home designer expert, she has a keen eye for the latest home improvement trends with accurate facts that readers find impossible to ignore. Being invested in home-building trends is how she has gained her lucrative expertise exploring more to bring a positive ambiance for all homeowners (and even tenants!). Currently, she lives in a beautiful beach home, a source of fascination for her.