DIY Cement Patios

Site Preparation

• 1

  Dig a hole at least 1 foot deep in the middle of your proposed patio and examine the dirt. If your soil is consistently sandy below the surface, you have no need for a gravel foundation. If it is clay or loam, as is the case in this example, you do need a gravel foundation.

• 2

  Mark the perimeter of your patio with stakes. Tie string to each of these stakes, creating a visual reference for the sides of your patio. If the results are crooked or misaligned, adjust the placement of your stakes accordingly.

• 3

  Excavate the area inside your perimeter. Your concrete patio must be 2 inches thick, plus have at least another 6 inches of gravel beneath it, so you must dig the patio work site down to a minimum depth of 8 inches.

• 4

  Line the sides of the patio space with hardboard siding, set so that the tops of the boards extend at least 2 inches above ground level, creating an even, straight mold for pouring cement. Reinforce the hardboard by driving stakes outside the boards at intervals of 2 feet.

• 5

  Dump gravel into the work site, filling it to a depth of between 6 and 8 inches.

• 6

  Use a piece of scrap timber, such as a length of 2-by-4, to ensure the bed of the patio is flat and level. Move the timber by sections down the length of the patio, checking the timber with a carpenter's level each time, until you have checked the entire bed of the patio. If any area is not level, add or subtract gravel and smooth it out with an iron rake.

Pouring Cement

• 7

  Mix your cement as directed by the manufacturer, using either a cement mixer or by hand in a wheelbarrow with a stick. Move the cement to the work site with a wheelbarrow (or the cement mixer itself, if it is a small one) and dump it into the patio bed.

• 8

  Instruct your assistants to even out the cement with an iron rake while you go back to mix more cement (or visa versa). Continue the team effort of mixing, pouring and raking until the hardboard mold is almost full, and then instruct your helpers to start smoothing out the top by drawing the scrap timber you used to level the gravel earlier across it, using it as a screed.

• 9

  Smooth the surface further by running a bull float over the surface three to four times. Round the edges of the concrete with an edging trowel.

• 10

  Monitor the cement as it hardens. Pools of water should form in the surface and then be reabsorbed before you move on to the next step.

• 11

  Cut expansion grooves into the patio surface using your edging trowel. As a rule, you need an expansion groove to allow the cement to expand and contract without cracking for every 10 feet of concrete surface. If you pour a 12-by-12-foot-square patio, that is more than 10 feet long and wide, so it needs an expansion groove for both axes. The most symmetrical course of action is to cut a groove down the middle, dividing the patio into what looks like four square blocks.

• 12

  Smooth out the patio again with a magnesium float. Allow the concrete to harden overnight, then pull up the stakes and pull out the boards.