Standing water can cause problems with concrete surfaces, especially in a climate where temperatures drop below freezing. It is necessary to make sure that water drains from the surface of your concrete so that trafficked areas aren't slick and so that the concrete isn't damaged by water or ice. Installing a channel drain in your patio, driveway or other concrete surface will make the surface safer to walk on and increase the lifespan of your concrete.
Determine the best place for the channel drain to be installed by examining your concrete surface to see where water naturally runs to. It is logical to place the drain in an area where water is already naturally running.
Measure the length of the area where you will be placing the drain. If you want to effectively drain water from a driveway that runs alongside a sidewalk, place the channel drain in the area where the driveway meets the sidewalk (especially if that is where water tends to run and puddle). Start at the point where the driveway and sidewalk meet the house and measure to the street or curb. This measurement will determine how many lengths of channel drain that you need to purchase.
Mark with chalk the area where you will be placing the drain. Use the measuring tape to mark an area 1 1/2 feet wider than the width of your channel as you need room to slope the concrete surface down toward the channel. If your channel is 6 inches wide, mark out a 2 foot wide area in which to cut an opening to drop the channel down into. It isn't necessary to mark full, solid lines for the entire length of the project. The marks are being used as guidelines and only need to be a few inches long every several inches to give you a guide to follow.
Cut an opening in the concrete with the concrete saw starting at the point nearest the house and working toward the curb, using your chalk markings as a guide.
Clean the excess concrete debris, gravel and soil out of the opening and discard it.
Measure the depth of the opening at the point nearest the house, at approximately the midpoint and at the curb. The measurement at the curb should be at least 2 inches lower than the point nearest the house and the midpoint measurement should be somewhere in between. The point nearest the house should be at least as deep as the channel so when you set the channel inside it won't protrude above the existing concrete surface. If your channel is 4 inches deep then the depth of the opening at the point nearest the house should be at least 4 inches and the measurement near the curb should be at least 6 inches.
Dig your opening down or fill it in, if necessary, so that it slopes appropriately.
Attach the sections of channel together to create one long channel. They are made to interlock with each other and easily snap together.
Set your channel down inside the opening, centring it so that there are equal amounts of open space on either side.
Mix the cement according to the instructions on the packaging.
Pour the concrete into the opening along one side of the channel. Use the hand trowel to slope the concrete up from the edge of the channel to the edge of the existing concrete surface. Once you complete one side, pour the other side, using the trowel to slope the edge.
Use gravel or sand to fill in the opening to correct the slope, if necessary, before setting the channel down inside of it. You can purchase either of these at a home improvement or gardening store. Each channel section has a grate attached to the top of it. It isn't necessary to remove these pieces when pouring the concrete, but it is recommended that you tape over the grates with masking tape. This will keep wet concrete from splashing into the grates as you work. Channel drains should be considered when constructing any concrete project. The installation of one when the surface is being poured to begin with will prevent the water problem from the outset and will eliminate the need to remove sections of concrete later on.