DIY Builds
Photo by Sunsetoned Pexels Logo Photo: Sunsetoned

How deep should you cut joints in concrete?

A good rule of thumb is to cut the joints one-quarter to one-third the slab thickness. For a 6-inch-thick slab, that means cutting 1 1/2 to 2 inches deep. Ensure that the saw cut depth meets the structural engineering specifications.

thespruce.com - When, Where, and How to Make Saw Cuts in Concrete - The Spruce
Which gravel is best for drainage?
Which gravel is best for drainage?

In general, you want to aim for ½ inch to 1-inch gravel for drainage. Areas that will see especially heavy flow may need larger gravel. Or,...

Read More »
Last updated May 15, 2020
Can I run Internet to my shed?
Can I run Internet to my shed?

Powerline adapters use your home's electrical wiring to deliver internet. If your shed also shares electricity with your home where the WiFi modem...

Read More »
Last updated Sep 17, 2022
Are shed plans easy to follow?
Are shed plans easy to follow?

These are! They guide you every step of the way to complete your dream shed.

Learn More »
Promotion

Saw cuts are a used to create control joints in concrete, which help control where cracking occurs due to shrinkage. The cuts should be made at a predetermined spacing and only after the concrete has obtained sufficient strength but before internal cracking begins. Therefore, the timing of saw cuts is critical. Determining when to make cuts depends on many factors, including the type of admixtures and aggregate used in the concrete, the air temperature, and the concrete's mix design. Tip Making saw cuts in concrete can be a very technical process: If you're unclear on the process or project, call a professional.

When to Saw-Cut Concrete

In addition to the concrete mix and the weather conditions, determining when to saw concrete is based on the concrete's hardness as well as the type of cutting equipment used to make the saw cuts. Cutting too early causes raveling, an effect created by the saw blade pulling the aggregate out of position, leaving a messy, weakened edge along the cut. This also causes undo wear on diamond concrete saw blades. Sawing too late can result in uncontrolled cracking as the concrete contracts during curing. Saw cutting can start anywhere from three to six hours after the concrete is poured, depending on the weather conditions. The best way to determine whether the slab is ready is to make trial cuts to check for raveling. Saw cutting should start as soon as the raveling stops during these trial cuts. Some contractors delay sawing to protect their equipment and saw blade to reduce blade abrasion. There are several types of saw blades that can be used, depending on the concrete type and how soon the cuts can be started. Other factors that can lead to excessive blade wear and joint raveling include:

Pushing the blade too hard

Saw cutting at high speed

Using a saw with a bent spindle

Using an inappropriate saw blade

Where to Saw-Cut Concrete

Before you start saw cutting concrete, is important to select where these cuts will be done. It is recommended to start saw cuts on or at the center of column lines. Joints shall be spaced at 24 to 30 times the slab thickness but this need to be confirmed by a structural engineer. Joint spacing normally ranges between 12 to 18 feet depending on the amount of reinforcement the slab has. If you are using high shrinkage concrete, you might want to decrease the cut spacing. Here are other factors that will help you determine where to saw cut:

Try to form square patterns

Do cars last longer when kept in garage?
Do cars last longer when kept in garage?

Vehicle exteriors are kept in much better condition when stored in a garage which can lead to greater resale values. Because a garage keeps a...

Read More »
Last updated Jun 19, 2020
How deep should a footing be for a garage?
How deep should a footing be for a garage?

Footings should extend to a minimum depth of 12 inches below previously undisturbed soil. Footings also must extend at least 12 inches below the...

Read More »
Last updated Dec 28, 2018
Can I build my own shed?
Can I build my own shed?

Yes, with the right plans you can build your dream shed.

Learn More »
Promotion

Make saw cuts continuous

Select an area that doesn’t have continuous steel reinforcement from one slab or square to another. It is better to have smaller cracks than to increase cost by having and maintaining several joints. Under hot weather conditions, you might want to try forming a larger square and then cutting interior joints. By doing this you will be controlling fast setting concrete cracks in larger areas.

How to Saw-Cut Concrete

Factors such as curing techniques, slab thickness, and base type must be analyzed before selecting where joints should be cut. Once you've laid out the joints to be cut, mark them using a chalk line. If you're using water cutting equipment, make sure that the water is running all the way down to the blade. Allow the blade to reach the required depth, then start walking or moving the equipment following the chalk mark. Here are some recommendations when sawing concrete:

Do not twist the saw blade.

Do not let the blade spin in the cut, as this will increase wear on the bond. When cutting concrete with heavy rebar, use blades with soft metal segment bonds.

Always ​​use the required PPE (personal protective equipment).

How Deep to Make Saw Cuts

A good rule of thumb is to cut the joints one-quarter to one-third the slab thickness. For a 6-inch-thick slab, that means cutting 1 1/2 to 2 inches deep. Ensure that the saw cut depth meets the structural engineering specifications. If the joint is too deep, aggregate interlocking will not be sufficient to transfer loads. If the saw cut is too shallow, random cracking might occur.

thespruce.com - When, Where, and How to Make Saw Cuts in Concrete - The Spruce
How much is SketchUp for woodworking?
How much is SketchUp for woodworking?

SketchUp Free is freely available, whereas SketchUp Pro ($299/year) and SketchUp Go ($119/yr) are a yearly subscription. Jun 28, 2022

Read More »
Last updated Apr 17, 2018
What is the minimum pitch for a shed roof?
What is the minimum pitch for a shed roof?

I always recommend at least a minimum pitch of 1 in 40. This translates into a fall of just under 2.5"" on an 8 foot roof. Fix your roof deck and...

Read More »
Last updated Aug 24, 2019
Can I build my own shed?
Can I build my own shed?

Yes, with the right plans you can build your dream shed.

Learn More »
Promotion
How much power do I need for a shed?
How much power do I need for a shed?

Larger equipment needs 240 volts, like a dryer or electric range. Running 240 volts to your shed requires using a different type of breaker in your...

Read More »
Last updated Mar 24, 2020
What do you put on the bottom of a metal shed?
What do you put on the bottom of a metal shed?

What to Put Around the Bottom of a Shed? Lattice. Save. ... Concrete Block/Landscape Blocks. Save. ... Brick. Save. ... Pressure-Treated Lumber....

Read More »
Last updated Oct 6, 2022