Why Does concrete crack?

By
Home Builder with Rescue Concrete Inc.

As a Concrete Professional for the last 11 years I have been asked time after time, "Why does concrete crack".  There is a multitude of reasons that concrete cracks.

 

Here is a quick list of reasons that concrete cracks:

 

1. Too much weight applied to the surface of the concrete via a truck, or a forklift

2. Soil conditions, as you may know clay soil is highly expansive, and can damage concrete, if not engineered properly

3.  No crushed rock or A.B (aggregate base) underneath the concrete

4. Tree roots (very common) as trees grow roots grow and then they push up the concrete

5. improper installation of joints in the concrete, if the expansion joints are too far apart, then a crack will want "jump" out of the joint that it is supposed to be in

6. Poor finishing technique, if you do not finish the concrete fast enough or too fast (depending on weather conditions) you can get a crack

7. Dry winds, anytime you have low humidity and even moderate winds can lead to cracking into your concrete

8. The wrong aggregate, too many sharp edges on the aggregatte can lead to cracking

9. Expansion Joints not being deep enough into the slab. You want to be in control of the concrete and not the concrete in control of you.  Putting expansion joints where they need to be will help you mitigate most issues of cracking

10. Most important! hire the best, when you hire a concrete contractor take three bids and choose the Medium to highest bid, and expect the best:

-Quality

-Safety

- Consistency

 Too many times people choose the cheapest price and it only hurts them in the end.  Concrete work is for 20 years plus, when you purchase concrete it is a commitment.  Go cheep on a meal before you go cheep on concrete. It is better to spend your hard earn money on something that will last for a generation.

 

 

 

 

Comments (10)

Dwayne West
Atlanta Real Estate - Canton, GA
Canton Georgia Real Estate
This is some very good information. I have always wondered and had some questions about cracking concrete on some slab houses I have looked at.
Mar 14, 2008 08:21 AM
Scott Hutchinson
REAL ESTATE - Lago Vista, TX
Lago Vista Real Estate
Good to know.  Money well spent in the beginning may save pain and suffering later on.
Mar 14, 2008 08:23 AM
Nicholas Winn
Rescue Concrete Inc. - Rancho Cordova, CA
Yes, I am glad I can be of help, if you have any more questions let me know. Send pictures if you can
Mar 14, 2008 08:24 AM
Harold "Hal" Place
A1 Connection Realty, Inc. - Sun City Center, FL

Hi Nick, Very informative post.

Hal

Mar 14, 2008 08:39 AM
Nicholas Winn
Rescue Concrete Inc. - Rancho Cordova, CA

Hal, Thank you for the kind words!

 

If you have any other concrete topics let me know.  Maybe and can help you and others! 

Mar 14, 2008 09:01 AM
Benjamin Clark
Homebuyer Representation, Inc. - Salt Lake City, UT
Buyer's Agent - Certified Negotiation Expert

Welcome to Active Rain! For some tips on how to get started here, check out my blog entry at ActiveRain Fast-Start Tips for Quick and Easy Points

Happy blogging and good luck!

Mar 15, 2008 05:10 PM
The Trumm Team Omaha Homes for Sale, Real Estate
Keller Williams Greater Omaha - Omaha, NE

Welcome to ActiveRain!

If you would like a few tips on getting the most out of ActiveRain, please visit my blog Welcome to Active Rain.  It has a few simple steps of what to do now that you have joined.

If you ever have any questions, just let me know.

Troy Trumm
Mar 16, 2008 10:28 AM
Anonymous
ebenezer essel

i want to know the influence water has on concrete mix

Oct 22, 2009 05:54 AM
#8
Anonymous
Nicholas Winn

When you have a mix design for a speicific project, and you exeed the amount of water that should go into the concrete mix, you can cause the following failers:

 

-If the project has integral color, you can dilute the color to the point where it is muted and looks washed out

-If the project needs high early strength you can reduce the chance of the concrete getting up to the PSI it needs at 28 days.

-Too much water can cause "spider web" cracking or plastic shrinkage cracking

-Too much water can cause dusting, concrete starts to degrade to the point where it starts to "dust" onto your hands.

-Too much water can reduce the longevity of a concrete slab

Oct 22, 2009 07:26 AM
#9
Anonymous
Nicholas Winn

When you have a mix design for a speicific project, and you exeed the amount of water that should go into the concrete mix, you can cause the following failers:

 

-If the project has integral color, you can dilute the color to the point where it is muted and looks washed out

-If the project needs high early strength you can reduce the chance of the concrete getting up to the PSI it needs at 28 days.

-Too much water can cause "spider web" cracking or plastic shrinkage cracking

-Too much water can cause dusting, concrete starts to degrade to the point where it starts to "dust" onto your hands.

-Too much water can reduce the longevity of a concrete slab

Oct 22, 2009 07:27 AM
#10