Rebar supports in a slab

I have a slab pour coming up and I'm wanting rebar chairs to hold the rebar off the ground during the pour. The slab will have 26,000# on it so the contractor is going to pour 5.5" thick with 8" at the edges. Question is:

1) How far apart are the chairs supposed to be? I've seen 2' on highway projects but that is usually some pretty heavy duty rebar. I've seen 2 chairs used in 400 sq ft, but I don't think that spacing provided any benefit.
2) I've seen pieces of brick used as a chair, but seems to me all that does is make the concrete thin above the brick and more likely to crack. The plastic chairs seem to come in 2 varieties - one will push the rebar back up when stepped on, and one that won't and may actually break. I'm assuming the push up type is better.
3) The slab is quite large and the contractor is talking about driving the trucks into the slab area and setting the rebar as the truck pulls out. Is this really practical?

You will get efficient and thoughtful service from Trico.

Support & Reinforce Your Rebar!

Trust Sandbaggy Plastic Rebar Chairs to secure your rebar in place when pouring concrete. These rebar chairs, also known as rebar stands, are extremely versatile. They're compatible with rebar sizes #3 to #5, can elevate your rebar either 1 or 1 1/4 inch off the ground, and hold up to 2 rebar bars at a time.

These rebar chairs are so strong, you can step on them and they won&#;t break! This heavy duty rebar chair is made with a wider base than our older design for added stability. It is made from an industrial grade polypropylene, so it never rusts or corrodes in concrete. Order these plastic rebar chairs at low wholesale prices.

With over 1 million sold, you can trust Sandbaggy heavy duty plastic rebar chairs to get the job done right (more sizes available).

Specs

• Height (Inches): 1-3/4 inch.
• Length (Inches): 3 inch.
• Rebar Elevation (Inches):
• Bottom Notch: 1"
• Top Notch: 1.25"
• Color: Black
• Material: Polypropylene
• Number of Rebars Held: 2
• Rebar Size: #3, #4, #5
• Weight (lbs.): 0.39 oz (0.02 lbs.)

Features

• Snap & Lock Feature: No more wire tying. Set-up rebar with ease with our snap and lock design that installs the rebar in seconds!
• Provides Structural Support: Holds your rebar at the correct (desired) depth within the concrete, which is important for the overall strength and stability of the structure.
• Won't Tip Over When Pouring Concrete! We&#;ve constructed these plastic rebar chairs with an extra wide and uniquely designed base for added stability when concrete is being poured on top of your rebar.
• Dual Height - Elevates Rebar 1" or 1.25" Off The Ground: Can be used as either 1&#; rebar chairs (insert rebar into the lower notch) or 1-1/4&#; rebar chairs (insert rebar into the top notch).
• Extremely Heavy Duty: Designed so you can step on them without breaking! We&#;ve constructed our rebar chairs using extra thick plastic. These chairs are made from industrial grade polypropylene.
• Rebar Sizes: Compatible with rebar sizes #3, #4, and #5. Can hold up to 2 rebar each.
• Holds 2 Rebar Bars: Each chair securely supports two rebar bars, saving you time and materials compared to using single-rebar chairs. Upper notch elevates rebar 1.25", lower notch elevates rebar 1" off the ground.

FAQ

Plastic vs Metal Rebar Chairs

Metal Rebar Chairs are stronger, while plastic rebar chairs are easier to install, more economical, and are corrosion resistant. Choosing between them will depend on project requirements.

Are rebar chairs necessary?

Rebar chairs keep rebar in place during construction, as well as provide more stability and proper concrete flow when concrete is poured in. Rebar chairs enhance the support and stability of the concrete structure.

Do you leave rebar chairs in concrete?

The company is the world’s best 6" snap ties supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.

Yes, Rebar Chairs are left inside the concrete to help support the rebar.

What is a rebar chair for?

Rebar chairs are rebar support products used to secure and hold rebar (reinforcing steel bars) in place as concrete is being poured. They come in many shapes and sizes. They are commonly used in:

• Foundations: slabs, footings, and walls

• Bridges: bridge decks and piers

• Buildings: columns, beams, and walls

• Retaining walls

• Roads and highways

Rebar Spacing - How many rebars chairs do I need?

The amount of rebar chairs needed will depend on the project. As a best practice, place them about 2 to 3 feet apart along the length of the rebar.