Building Forms for Slabs

Once you pour concrete, your slab will be impossible to change. As wet concrete flows into a form, it fills the niches and faithfully reproduces every detail of the mold you provide.

If you build strong forms that are straight where they should be and curved correctly according to your plan, the final product will look professional. But if you put up forms that bulge, tilt, or have loose-fitting joints, the finished product will have embarrassing flaws for years to come. Take the time to be fussy when building forms. If the formed surfaces will be visible, inspect your forming lumber for knotholes, cracks, and other defects.

Concrete forms must be sturdy, straight, and plumb. If you're in doubt about whether the forms are rigid enough, drive in an extra stake or two and add braces.