When it comes to pouring concrete, cracking and shrinkage over time is inevitable. This is due to concrete’s lack of tensile strength, causing shrinkage to crack your slab.
By understanding that these issues are going to occur eventually, you can take the proper preventative measures now to plan for and postpone them down the line.
There are several tried and true methods for reducing concrete cracking and shrinkage. A good concrete contractor can be expected to mention the words “control joints” in relation to cracks.
But what are these, exactly, and why are they used? For starters, there are four main reasons why concrete contractors use control joints. These joints are preferred because they:
1. Allow concrete to crack where you want it to
Of course, no one wants concrete to crack, however, choosing where it cracks when it does can make a world of a difference. Control joints plan for cracks ahead of time and allow for strategic placement in order to manipulate the cracks into occurring in certain spots. This will also make them easier to find as they appear.
2. Increase durability and decrease the number of cracks
Because control joints account for all the future cracking of your concrete in advance, the overall durability and reliability of your slab will increase.
While your concrete will still be expected to crack as it ages, these joints will decrease the number of cracks, prevent random cracking, and give it an overall beautiful finish.
4. Make it easier to fix cracks
Because control joints make cracks easier to locate, this in turn also makes cracks easier to fix. Your contractor will let you know where to expect cracking to occur so that you can keep an eye out on these areas and fix small cracks as they pop up.
5. Allow cracks to occur in a straight line
Control joints strategically map future cracking, allowing for your concrete to crack in a straight line rather than randomly. Not only are these cracks easier to fix, but they’re less of an eyesore than sporadic, spidery cracks.