How to Repair Concrete
If you have a sidewalk on your property, odds are you’re going to have to repair it at some point.
Concrete is a durable, versatile material, but there are many factors that can lead to a damaged sidewall:
- Roots can crack pieces and push them out of alignment
- Cold temperatures and ice can lead to damage
- Normal wear and tear can create dangerous situations or unsightly problems
So we’re going to go through some basic sidewalk repair and show you that with a little know-how, and some standard tools, you can do it yourself and do it right.
Concrete is a composite material that’s made from a few different elements. The mix of fine and coarse pieces is held together by a liquid cement binder. This means that getting the right mix of water and concrete is key to the right strength and drying time.
Check your package instructions, but generally you’re looking to create a peanut butter consistency. Concrete works best between 50 and 80 degrees Fahrenheit when there is no rain.
There are lots of different types of concrete that you can find at the store, covering all kinds of applications:
- water-resistant concrete
- fast setting concrete
- high-strength concrete
- reinforced with fiberglass concrete
- countertop style concrete.
Make sure you choose the type that is recommended for your project.
How to Repair Concrete Cracks
There are two levels of sidewall crack you might see, a hairline crack or a wider crack.
For a hairline crack, remove any loose debris from the damaged area with a wire brush and broom, then you can use a caulk gun loaded with a masonry crack filler to fill the crack, or you can use a vinyl concrete patching agent and a putty knife to fill it in.
For a wider crack, you will need to use a small sledgehammer and a chisel. You want to make the bottom of the crack wider in the top, which sounds tricky but it just means angling the chisel to lock the patch in place and keep it from moving.
Clean the debris with a wire brush and broom. Wet the area and then fill the crack with a vinyl patching mix and a trowel.
How to fix Concrete Edge Damage
We’ve all seen concrete with crumbling edges and missing corners, but don’t worry we can fix that too.
If it’s more than just a broken edge or a missing corner, you may have to replace the whole section, but if it’s a localized problem, you can fix it.
First, clean out all the debris with a wire brush and a broom, and chisel out until you have strong concrete on all sides. If this piece will see a lot of traffic or weight, like a concrete step, then you’ll want to drill out a hole with a masonry bit first.
Take a piece of steel dowel, called a rebar rod, coat it with a latex bonding product, and insert it into the hole, halfway. Apply the same bonding product to the broken edges of the side wall, making sure to get into all of the crevices.
Mix up your concrete patch with water and add some of the bonding product to the mix. Read the manufacturer’s instructions for specific amounts. Use your scrap wood to create a form for the concrete to shape to.
Put your mixture into the form with a trowel, tamp it down, and smooth out the top. You can use a broom to lightly score the top for a texture.
Leave those boards in place for a week until it dries and then you’ll be good to go.
How to replace a concrete section
When a piece of your sidewalk is too damaged to use, it can be best to just rip it out and start over.
First you will need to remove the existing sidewalk piece. Once the piece is gone, clear any rocks or debris from under the spot where you will put the new slab.
Dig around the edges to create a perimeter, then it’s time to build a form.
You want the top edge of the form to be even with the existing sidewalk so it all sits flush.
Use stakes or scrap wood to hold your form in place and place the stakes regularly to avoid the form from bowing outward. Make sure the stakes sit below the top edge of the form or else cut them flush.
Spray the inside of the form with oil for a clean release. Put a couple of inches of sand in the form and wet it down.
Mix your concrete and pour it into place, making sure to get into all the corners. For an easy way to find out how much concrete you’ll need to use, you can check out an online concrete pad calculator.
Then comes the screed. Screeding is when you use a longboard to flatten the concrete.
Move it slowly from one end to the other, with a short sawing motion, and ddd concrete to any low spots as you go.
Then you will lightly smooth the surface but be careful not to dig the float corner in or you will have to rescreed.
Let the concrete dry for 30 minutes then use a broom to create a non-slip texture. Lightly place some plastic on top and let it dry for several days. Remove the plastic and let it dry for a couple of more days and only then you can remove the forms and replace the dirt around the edges.
So we’ve covered everything from tiny cracks to replacing whole sections and while some of it can be time-consuming, you can do it yourself, and you can do it right.