\Concrete can be a low-maintenance yet attractive option for pool decking. A popular choice among pool owners for decades now, using concrete for pool decking can be a great choice because it is durable, long-lasting, affordable, fairly slip-resistant, and water-resistant. In addition, pool owners can have concrete poured into nearly any shape or design they can imagine, which makes concrete highly customizable and easy to suit any home’s exterior aesthetics.
Although concrete is an excellent choice for pool decking, it does tend to crack over time. Cracks in concrete can be unsightly as they distract from the natural beauty of your pool area. They can also be dangerous. From stubbed toes to serious trips and falls, cracks can jeopardize your family’s safety. Furthermore, large cracks can either indicate trouble beneath the surface or lead to greater problems if water seeps into untended cracks. You may have your day-to-day pool care routine down, and you may know what to do when your pool water’s chemistry is out of balance, but what do you do when you notice the concrete around your pool cracking? Not only will this in-depth guide help you assess and remedy the situation, but it will also cover effective ways to minimize the potential of the cracks in your concrete pool decking getting worse.
Why Does Concrete Crack?
There are a myriad of reasons you may find the concrete around your pool has cracked. From weather to soil to improper installation, there is not always one single cause for cracks in concrete. It’s often a combination of reasons that have caused cracks in your concrete. These common causes of concrete damage are the likely culprit for your pool decking problems.
In the Cold?
Weather can have a tremendous impact on concrete. For example, if rainwater and melted snow seep into small cracks, they can freeze. The repetitive freezing and thawing cycle of water molecules can cause them to expand, which leads to cracking and damage to the concrete.
What About When it’s Hot Out?
Summer is no relief to the concrete, either. When the temperatures start to rise, there is expansion and contraction beneath the surface. The effects of thermal expansion will vary depending on the aggregate type.
Do you have trees or large shrubbery near your pool deck? Tree roots can be a danger to concrete. From sidewalks to patios to your pool deck slabs, any concrete surface can be susceptible to root damage. A good contractor will discuss existing landscaping with you when installing a pool, but if a tree was planted or started growing spontaneously after the concrete decking was installed, it could be a problem if it’s too close.
If the concrete was not mixed correctly (for instance, with too much water), or a low-strength concrete was used, it could be weaker than normal. Weak concrete is more prone to damage.
In-Ground Pools Can Actually Shift
It is entirely possible that your pool could shift, or even float upwards due to hydrostatic pressure, which is the pressure of underground water. This can happen after flooding, in areas with high water-table levels, or from various other causes. As your pool shifts, the concrete can be affected.
You can often tell if your in-ground pool is not level by checking the water level against the horizontal grout line. Look at the water level around the pool’s edge – the water level should be the same distance below the grout line all the way around the pool. For instance, if the water level is two inches below the grout line on one end of the pool, but only one inch below at the other end, it is not level. The tile should have been installed level around the pool, which means this is a simple way to determine how much, if any, shifting your pool has undergone.
Unfortunately, when a contractor installs a pool, the soil around the pool does not always get compacted well. When the earth underneath shifts naturally or slope creep occurs, the ground underneath the concrete slabs may move. When a slab moves, there is likely to be cracking. Of course, the more movement that occurs, the more cracking or damage is likely to happen.
Many soils, such as those with higher clay content, tend to expand when they get wet. Similar to expansion from temperature fluctuations, soil expansion, even if it was compacted correctly, can lead to cracks in the concrete. Once there are cracks, more moisture can enter the soil, creating the possibility of more damage.
Improper Control or Expansion Joints
Contractors are fully aware that concrete is prone to cracking, which is why control and expansion joints are placed when the concrete is poured initially. When set correctly, the joints will help reduce cracking. However, if the contractor spaces the joints too far apart, cracks in the concrete decking may appear. It is recommended not to space the joints more than 10-12 feet apart to prevent cracking.
Failure to Seal Small Cracks When They First Appear
Just like routine pool maintenance can help prevent costly problems down the road, the same goes for maintaining your pool deck. Neglecting to seal minor, seemingly insignificant cracks when they first appear can lead to larger, more costly damage down the road.
Tools You’ll Need on Hand to DIY Repair Concrete
The tools you will need to repair the concrete cracks around your pool will depend on your chosen method. However, there are a few standard tools that you will need in order to do the job yourself.
A garden hose will help you wash the entire area and the crack(s) of dirt and debris.
You can use a wire brush to sound the concrete and clean additional debris from the crack(s) as you work.
Clearing the hollow concrete with a chisel helps reduce the chance of needing to make multiple repairs.
You will need to use a trowel to mix your chosen filler, fill the crack, and smooth the surfaces.
Paint thinner can be used to clean your tools as it is good at breaking down the mortar and epoxy residue that can be left by the concrete filler.
Repairing Deck Cracks
There are different methods for repairing concrete damage or cracks, so evaluating the various ways will help you make an informed decision on how to proceed.
If a pool deck has dropped or is sinking, slab jacking is a good alternative for lifting the concrete when it does not have many cracks. It is a minimally invasive, long-term solution to the problem and is cost-efficient in the long run. You will need a rock drill, grout mixer, and grout pump. Slab jacking, also called mudjacking, is best left to the professionals. However, if you happen to be a professional or have experience with slab jacking tools, you may be able to tackle this project yourself.
1. Drill Holes
Smaller slabs that have sunk may only need one or two holes. However, more significantly sized slabs, such as those more than four feet on a given side, may require three holes to be drilled in a triangular pattern. Generally, holes should be drilled three to eight feet apart while not less than one foot from the edge of the concrete slab. You should drill each hole an equal distance apart. The holes typically range between 1-2 inches in diameter.
2. Pump the Grout
At the lowest point of the slab, begin pumping the grout into the holes. As the slab rises, move from hole to hole. You will repeat this process while the concrete slab rises inch by inch.
3. Patch the Holes
Finally, remove any grout that remains in the holes. Then, fill it with the mortar mix and even out the surface.
Concrete Crack Filling
The method and material you use to fill the cracks in the concrete will depend mainly on the size of the gap. Therefore, choosing the correct filler is essential to ensuring it works properly.
- Concrete patch mix – Best suited for cracks that are wider than 1/4 inch, you can use concrete patch mix to match the texture of your concrete decking, but it is more challenging to match the color.
- Epoxy – for concrete cracks less than 1/4 inch wide, you can use resin-based epoxy fillers; they are a little stronger than polymer.
- Polymer-based filler – Also resin-based, you can use polymer filler for small and narrow cracks; it works similarly to epoxy fillers.
- Vinyl – Works well for cracks of all sizes, from more minor hairline cracks to wider cracks. Vinyl is a good choice if you have multiple cracks of varied sizes.
- Grout or Cement – These do not form a structural bond with concrete, but can be a good option for wider cracks.
- Mortar – Dry mortar is durable and less likely to incur shrinkage when packed into concrete cracks, but is best suited for deep cracks.
1. Clean the Deck
Thoroughly clean the concrete pool deck by spraying the area with your garden hose. Before you begin, clean out the crack, so it’s free of dirt and debris.
2. Remove the Hollow Concrete
Sounding the concrete is a non-destructive method of assessing the concrete. Tap the edges of the concrete with the end of your wire brush and listen for the differentiation in sound. A ringing sound will indicate solid concrete, while a flat or hollow sound will indicate the hollow area of the concrete that you will need to remove. Carefully chisel the hollow space away until you reach the solid concrete. Use your wire brush to clear away debris as you work.
3. Prepare Your Concrete Filler
Once the concrete is dry, you can use your chosen concrete filler. Make sure you read the manufacturer’s instructions carefully and have all tools ready. Do not begin mixing/preparing until you are sure you can fill the cracks because it can dry very quickly.
4. Fill the Cracks
Use your trowel to fill in the crack so it’s free of all air pockets. Failure to do so could mean more damage down the road, so it’s better to get it right the first time. Once you’re confident you’ve filled the crack completely, finish by smoothing out the surface.
5. Clean your work area
Clean your tools immediately using the paint thinner or other preferred cleaning method, and rinse thoroughly with water.
6. Wait 24 hours
It is essential to wait at least 24 hours for the repaired concrete to completely dry before you walk or place anything on it.
Mending larger cracks
Larger cracks can be more complex and time-consuming to repair. If you are unsure of which method or filler you should use, it may be in your best interest to consult with a contractor first. Not only will they assess the cracks and damage, they may need to staple or stitch more extensive cracks, which can help prevent them from reopening. If the cracks or shifting of your pool’s concrete decking was caused by bigger issues like your pool floating upwards, an earthquake, or other events that might have caused structural damage to your pool, having your pool and decking assessed by a professional before you begin working in the area yourself is always a smart choice.
Preventing Future Concrete Cracking
Hopefully, if there is anything you have learned from our pool maintenance guide, it is that pool ownership requires a good deal of preventative maintenance. Staying one step ahead helps you foresee potential issues and avoid costly problems in the future. This goes not just for managing your pool water’s chemistry and taking care of the pump and filtration system, but also for caring for your pool deck. Investing the time and effort for thorough maintenance and minor repairs is almost always more cost-effective and efficient than waiting for them to turn into severe problems before taking action.
One of the best ways to prevent the concrete around your pool from cracking is to keep it clean and routinely monitor for issues. When your pool deck is dirty, it becomes an ideal spot for algae, fungus, or weeds to grow between sections. These problems not only ruin the overall look of your pool area, they also make it slippery and dangerous. If the area is so dirty and grimy that you can’t see small cracks, you won’t be able to treat them, leaving you susceptible to more issues. Therefore, keeping the deck clean is not just for visual appeal; it is a preventative measure for keeping your pool decking safe and in good shape.
Pressure washing is the most efficient way to clean your concrete pool deck regularly. If you do not own a pressure washer and are not ready to invest in one, consider borrowing one from a friend or family member. Otherwise, you can often rent one from the local hardware store. You will also need a 15- or 25-degree spray tip and muriatic acid, which many pool owners keep on hand.
1. Clear the Clutter
Make sure to clear your deck of furniture, toys, plants, and other items. Ensure that pets and children do not get in the way while you work as well.
2. Rinse the Deck
Hook up the pressure water to your water source. Then, thoroughly rinse your deck to clean it of leaves, dirt, and other debris. Ensure that you spray well between the slabs to remove soil that could swell and cause cracking.
3. Apply Muriatic Acid
Always follow the manufacturer’s instructions to apply muriatic acid. You may wish to work in small sections if you are cleaning a large deck. This will help you break up the job and ensure each section gets applied thoroughly.
4. Rinse the Deck
Hold the pressure washer’s wand at a 90-degree angle with the spray tip attached, and spray the deck clean. Then, rinse the deck a second time. You want to ensure that the muriatic acid gets washed away and no residue is left behind.
5. Repeat as Needed
If necessary, you may need to repeat the cleaning process. If you have particularly difficult stains, you may need to try firmly scrubbing the area or allowing the acid to sit longer before rinsing.
Full Deck Resurfacing
If you really want to transform your pool area, you may be interested in a complete deck resurfacing. This process involves applying a thin layer of concrete around the perimeter of your pool. This is when you or the contractor will repair cracked concrete areas at this time. In addition, resurfacing allows you to change the color or pattern of your concrete deck, which means you can update your pool area to match your style preferences.
One easy way to prevent damage from tree roots or wayward seeds from dropping into tiny cracks is to plan your landscaping carefully. A landscape architect provides many benefits, from designing a visually appealing outdoor living space to making sure you place your plants far enough away from your concrete decking or other sensitive areas.
Common Concrete Deck Repair Problems To Be Aware Of
Unfortunately, there’s no way to totally prevent cracks and damage to concrete, so you should be prepared to face certain challenges when it’s time to repair. Common problems when repairing concrete include matching texture and color.
Depending on the type of filler you choose, you may be able to match the texture fairly closely. However, the more intricate the patterns and texture of your concrete are, the more difficult it will be to match. Even if you cannot get an exact match, a filled crack that’s slightly off aesthetically is much less of an issue or an eyesore than an open crack.
It is often more difficult to match the color of your concrete than the texture. However, the desired result is to fill in any cracks and reduce the risk of injury or further damage to your pool area. Again, a repaired crack that is only visible because of slight discoloration is preferable to an untended crack.
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Disclaimer: Pool ownership and maintenance is very complicated, and we know every situation is unique. While we’ve done our best to cover the best practices here, we encourage you to reach out to ProTuff directly at email@example.com with any specific questions you may have.