This week we discuss how to fix puddling from improper concrete laying or settling.
Q: I laid a concrete slab in my backyard last year for a one-sided basketball court for the kids. There is lots of water sitting in the middle of my pad after it rains. It’s not that big so I’d rather not tear it out. What can I do to fix it? – Tim Reese
A: Thank you for your question Tim! This is a common problem because there are many physical factors involved in concrete laying. The cause of uneven concrete is a major factor. First, determine the cause of the sitting water.
What You Should Know First
DIY repair jobs on concrete can be hit-and-miss. The reason for this is multiple. First, the color of existing concrete might be different from that of the new concrete. The patches may not be as durable as a concrete batch. It can also be difficult to accurately level the concrete patch. You should weigh your options. While you might be able to do the job yourself, you’ll eventually need to replace the pad. Continue reading if you feel confident enough to proceed.
Determining The Cause
Firstly, you must determine if the concrete is bowing down due to settling or puddling.
- 1. Settlement occurs often in areas where water accumulates.
- 3. Makes the concrete look cracked or ‘spider-webbed’.
- 2. Often has a ‘trajectory line’ where the settlement occurs; for example, if it occurs in one square foot you will probably see settlement nearby in a linear pattern or patches.
- 1. Without using levels, it is sometimes difficult to see.
- 2. It gives a smoother appearance than settlement.
It sounds like concrete settlement, not puddling. It is more difficult than puddling to repair concrete that has settled. The bigger concern is the possibility that your cement is starting to settle. While you can do some things to help it settle again, the greater concern is the possibility of it happening again.
We recommend that you contact a professional to raise the basketball pad if there is any settlement. This is safer and easier than trying to do it yourself. We also urge you to check around other places on your property to ensure your home isn’t experiencing any settling also. Learn more about settling.
We will now discuss how to fix the problem of puddling.
Clean It Thoroughly
The first step is to clean that pad deeply. Even small particles of grime can make it difficult to place a patch. The pressure washer is a great tool. Spray it, then spray again. Make sure the water runs completely off the pad. It is possible to perform a more thorough cleaning job such as an acidetch depending on the size of the puddle.
If you don’t have a pressure washer a hose will work, but you will need to wash, rinse, and repeat over and over again. It might be worth using a scrubber to clean the area.
Evaluate The Depth of Repair
If you have a very small amount of area that needs patched (i.e. A liquid that is more liquid can be used if you have less than one vertical in. You will need a thicker mixture, with some rock added. It is up to you to decide which type of patch you want, but this universal rule applies more than just concrete. If you buy cheap, your rewards will be small. You want to do a good job. These concrete mixes can be found at most home improvement stores. You will probably only need one bag for a small job.
- 1. Use a 2×4, or several, to lay across the puddling. This is going to act as your level – bringing the new patch up to the bottom of the board. This will ensure that the patch is perfectly level with concrete. Note: Use discretion when using a level on your concrete pads. Sometimes concrete may not be level at all.
- 2. Prep the pad by soaking it in water. Concrete The pad will not be able to absorb water if it isn’t wet. Therefore, ensure the existing slab has water.
- 3. Mix the concrete. Remember, thicker concrete will make a stronger patch.
You first want to add a primer coat, then follow it up with the full patch (either a patch mix or concrete with a bonding agent). This combination will ensure that proper bonding is achieved.
- 1. Mix the primer according with the bag’s instructions. (Remember: thick aggregate is for larger patches; thin aggregate is for smaller ones).
- 2. Apply the primer to the patch and smoothen it using whatever tool you prefer – a trowel or a board. For this portion the primer should be very thin. Just enough to cover the area lightly (around 1/8″ deep).
- 3. Combine the patch mix and water. Alternately, you can use normal concrete mix and a bonding agent. These should be placed near concrete in the store. You should use your best judgement when purchasing a concrete mix and bonding agent.
- 4. Fill in the patch area and level it out with a trowel or 2×4.
- 5. Ensure that the patch lines up with the bottom of the 2×4(s) that you lined up as guides. The patch will look better if you take the time to ensure it is smooth.
As soon as the new concrete is laid down, you will need to add a curing agent. This will improve the patch’s longevity. This liquid substance is applied to the top of concrete. It can be purchased at the same location as your concrete, primer and bonding agent.
Concrete should stay put for about a week without being disturbed. This will help ensure that concrete is properly hardened.
After you have completed the patch, it should work as you originally intended. Coloration problems may require additional work.
A newly laid concrete may need to be reworked. If it fixes the problem of standing water on your pad, and doesn’t pose a threat to injury by people playing ball on the pad, then it will probably be fine to be left alone. However, you are probably aware that there are multiple factors at play that can cause concrete cracking. To make your patch smoother, you might need to try several different fixes or iterations. We won’t go into detail here but we would recommend that you consult a local expert or other guides about concrete cracking.
Vacuums For Concrete Cleanup
Understandably, working with concrete can be messy. HEPA Dry and Wet+Dry vacuums are available. HEPA vacuums filter out the smallest particles, including hazardous material such as silica from concrete. Even though they filter out tiny dust particles, the normal Wet+Dry Vacuums are great for slurry cleaning. Both vacuums can be used to clean concrete slurry or concrete dust.