How to Form Up for a Monolithic Slab

Things You\’ll Need

  • 2×4 wood planks

  • Wooden stakes (1x1x40 inches)

  • 1/2 inch plywood sheet

  • Saw

  • Hammer and nails

  • Reinforcing bar and wire ties

  • Rebar chairs

... Any concrete slab must be formed from a mold.

Monolithic concrete slabs are entire slab sections made in one pouring of concrete. Creating a form for a monolithic slab can be done easily with a few commonly found building materials, which you can buy at your local building supply store. Once set, concrete should be considered permanent, as breaking and removal is very laborious. Therefore, great attention and diligence should be paid while creating the form. Remember that concrete is a viscous material when being poured, so your form must comply with such rules of gravity.

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Step 1

Design the dimensions and shape of the slab you desire on paper.

Step 2

Build the skeleton (perimeter) of the mold using the 2×4's (if you require a slab deeper than 4 inches, use larger planks). Apply stakes outside the mold to prevent a blow out from just-poured concrete. Concrete is incredibly heavy and applies a lot of pressure on the perimeter of molds.

Step 3

Line the floor of the mold with plywood sheeting to provide a smooth surface to the underside of the slab. If making your slab on grade, this step is not necessary.

Step 4

Line the slab with rebar at intervals spaced for strength, sitting the bar on chairs to allow the concrete to sit both below and above the rebar, sealing it inside the slab. You are now ready to begin pouring your concrete into the mold.


Monolithic slabs must be created in one pour before curing to attain monolithic strength, set up your mold so that this can be done.