How To Perform Simple Concrete Repairs


Face it: hiring tradespeople can be expensive. Call-out fees, labour and materials can really add up, and before you know it, the bill for that simple tap replacement or wall patch-up will make you start thinking about taking out a second mortgage! So, next time you notice a crack in your concrete stairs or path, don't call your bank manager. Give DIY a try—you might be surprised how easy it can be.

What You'll Need:

  • Small sledge hammer and chisel
  • Wire brush and trowel
  • Cement mix (vinyl concrete compound works well, as it does not require a bonding agent)

Getting Started

First, use your sledge hammer and chisel to undercut the crack. This means making the crack wider at its base than on the surface—think of a triangle shape, with the vertex on the surface and the opposing side on the crack's base. This is done before performing the repair as it reduces the chance of the patch coming loose over the coming years.

Next, use your wire brush to clean the crack and the surrounding surface, and use running water to clear any debris away. Loose chips and stones can prevent the new cement mix from bonding with the existing concrete and increase the chance of another crack forming.

Performing the repair

Mix the vinyl compound as directed on the packaging. Generally, you will need to add about 300ml of water for every 2kg of compound. Be careful not to use too much water—a watery compound can weaken the bonding properties of the mix, making it more likely that another crack will form down the track.

Now, apply the compound mix to the crack using your trowel. The first layer of mix should be pressed into the affected area using firm pressure. This is done to remove air pockets from the compound. Once complete, smooth over the repaired crack with your trowel. Do not add further water once the repair is complete, as this can interfere with the setting process.

Taking care of your repair

Once complete, avoid walking over the repaired crack for at least a day. If your concrete repair is in an area that may face vehicle traffic, such as a driveway, consider fencing off or blocking the surrounding area for at least three days to allow the cement enough time to set.

Don't forget, as with any DIY project, safety comes first! Make sure you wear the appropriate protective equipment (gloves and safety glasses) at all times, and wear long clothing to keep the compound off your skin.


12 September 2016

Repairing my dad's old fixie

I really want a cool old fixie like some of the people at my university have, but they are actually more expensive than I had first thought. Then I was going through the shed at home, and I found a really old rusted bike my dad used to use. The bike needed a lot of work, so it's been a project for the last few months to get it working properly and get it looking great again. This blog has all of the repair and restoration steps that I have used, and pictures of my progress as the project progressed.