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How to Pour a Concrete Floor Outside

By Colette L. Meehan
A patio or other surface made of concrete is very low-maintenance.

A concrete floor outdoors can save homeowners time, energy and money because concrete lacks the ongoing maintenance associated with decks and paving stones. Durability, aesthetic appeal and environmentally friendly material are among the merits of concrete.

Pouring a concrete floor requires effort, planning and specialized tools. The weight of mixed concrete often necessitates several pair of hands. Enlisting extra people to help with moving and leveling the mixed concrete makes for a smoother process. Although pouring concrete remains a challenging endeavor, with the correct equipment and a little practice, it is a manageable do-it-yourself project.


Prepare the ground to receive the concrete. Remove loose soil and level the ground. This step is critical because uneven soil settling creates stress in the concrete that leads to cracking. Dig down about 4 inches and insert gravel, level again. Compact the gravel and soil thoroughly, until a solid surface forms; use a vibrating plate compactor for gravel soils.

Install form boards using 2-by-4-inch lumber. Position form boards along the perimeter of the floor and secure them at all corners. Insert wood stakes every 24 inches to hold form boards in place. Using circular saw, cut stakes to be even with the height of the boards. Form boards hold the concrete in place until it sets.

Take measurements to confirm the volume of concrete needed. Multiply the length by the width by the thickness to get cubic feet; divide cubic feet by 27 for cubic yards. A half-inch increase in thickness increases the required concrete by .37 cubic yard. As a precaution, always order more concrete than the measurement indicates necessary.

Pour the cement mix into the mixer using the correct ratio of water, gravel and sand. Typically, follow a ratio of one part cement, 1.5 parts gravel, 2.5 parts sand and 0.5 part water; read instructions on cement bag to confirm ratio.

Mix well. Mixed correctly, concrete slides off the trowel and smooths down easily.

Begin pouring the concrete into the farthest corner of the boards. Pour the concrete into piles slightly higher than the height of the form boards. Use the trowel to compact the concrete in the corners and along the edges. Level the concrete by pulling a 2-by-4, slightly larger than the form size, back and forth in a swinging motion.

Use a bull float to smooth out any imperfections on the surface. This process causes water to rise to the surface. After the water dries some, smooth the concrete surface one last time.

Cover partially dry concrete with a tarp. Allow concrete a few days to dry completely.


Things You Will Need

  • • Cement
  • • Gravel
  • • Sand
  • • 2-by-4-inch lumber
  • • Circular saw
  • • Float (hand tool that helps remove surface imperfections)
  • • Trowel (flat-bladed tool used for leveling)
  • • Cement mixer


  • • Coat form boards with motor oil so that they are easier to remove after the concrete dries.
  • • Pour concrete in temperatures ranging from 60-90 degrees F. These conditions allow time to touch up concrete if necessary; concrete dries in a reasonable amount of time.
  • • Concrete tends to climb the formwork around the edges. About a quarter of the way through curing, use an edger to prevent ragged edges.


  • • Wear protective gear to ensure safety at all times.
  • • Pouring concrete may appear easy. If the process becomes too cumbersome, enlist professional assistance.

About the Author


Colette Meehan is a freelance writer based out of Ardmore, Pa. Since graduating from Mount Saint Mary's University with a B.A., Meehan went on to earn an M.A. from Villanova University and an M.B.A. from La Salle University. She began her career in publishing, eventually moving on to finance and health care.