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How To Prepare The Building Site For The Concrete Slab

How To Build Your Own Home e-book available

Before You Begin

Tools Of The Trade

Designing Your Home

Building Permit Plans

Excavating Home Site

Laying Drain Pipes

Pouring The Slab

Installing Sill Plate

cutting Outside Wall Parts

Building Outside Walls

Framing & Raising interior Walls

Exterior Wall Sheathing

Cutting Out Openings

Wrapping The House

Preparing For Roof Trusses

Gettin Roof Trusses Ready

Raising Roof Trusses

Sheathing The Roof

Preping For Shingles

Shingling The Roof

Selecting Doors/Windows

Installing Doors/Windows

Preparing For Siding

Types Of

How To Select Siding

Siding The House

Siding Soffits & Trim

Installing Strapping


The next step is to prepare the buiding site for the slab. You must build concrete forms to give the concrete its shape, and also create a reinforcing mesh to protect the concrete from cracking appart.

The tools required for the job are: hammer, duplex nails, planks, rebar, bricks, wire, diagonal pliers, shovel, 2x4s, plastic sheeting, metal cutting blade for rebar, Tie wire tool, and sledge hammer.

  • How to make concrete forms
  • How to lay out a moisture barrier for poured concrete
  • how to lay reinforcements for poured concrete
  • How to place divider for concrete

  1. Making forms for the slab
    • Forms for a slab are perimeter constraints keeping the cement in place during the curing process. Forms give the slab its shape.

    • Select straight lumber with the width being 3" wider than the thickness of the slab.

    • Begin nailing the forms at one corner of the site using the markers already in place as a reference point.

    • If your board are not long enough to reach from one marker to the other, then join two together end for end with a scrap piece of board nailed on both ends as support. Be sure to use duplex nails as you will have to remove them carefully at a later time. Make sure the scrap lumber is nailed to the outside of the forms so as not to leave an imprint of it on the slab.

    • It is very important that all corners of the forms are square. This is accomplished in the same manner as squaring the perimeter stakes, using equal diagonal measurements from each corner.

      Squaring The Forms With Equal Diagonal Measurements

    • As can be seen in the image above, the sides must be kept straight by with 2x4 supports throughout, to prevent bowing.

  2. Spread and tamp a 3" layer of granular fill. Measure down from a string stretched across the forms. Slope the fill down along the edges to create a thickened edge of concrete.

    Slope The Fill Down On The Edges Around The Perimeter Of The Slab, For A Thicker edge

  3. Next lay a moisture barrier for the bottom of the slab.

    • This done by spreading 6 mil plastic sheeting over the gravel covering the entire area inside the forms. Make sure to overlap the plastic sheets.

  4. Reinforcing the slab
    • Lay a grid of rebar spaced 4' appart onto the plastic accross the entire of the length of the slab.

    • Now intersecting the existing rebar at 90* lay rebar again 4' appart accross the entire width of the slab.

    • Place a brick under each point of intersection and at the ends of each length of rebar.

    • Connect intersections with tie wire to keep rebar in place

    • Divide the slab down the middle with a 2x4 nailed to 1x3 stakes. Align the top edge with a taut string.

    Rebar Placed 4 Feet Appart With Bricks Supporting Each Intersection

{Next Step: Pouring The Slab}


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