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How To Prevent Concrete Patio From Cracking

How To Fix Cracks In Concrete

How to repair cracks in concrete patio and deck.

Small holes and cracks in a concrete can be repaired by yourself or a professional. Cracks can exist in varied diameters and depth. The type of patch compound to use will depend on the size of the crack.

Wider cracks are best sealed with a concrete patching compound such as mortar mix while smaller ones with a liquid concrete filler.

In your preparation for fixing a cracked concrete, you will need to have tools like hammer, chisel, wire brush, putty knife or trowel and a protective gear. Proceed to repair the crack in concrete as follows:

  • Using a hammer and a chisel, dislodge any loose material from the crack as you undercut the sides of the crack to widen its base. This will make the patch material to bond well with the old concrete.
  • Clean the crack first by using a wire brush and follow with a pressure washer or garden horse. This is to remove all the dirt, stains or any contamination that may affect adherence of a patch compound.
  • Drive all pooling water from the crack either by a wet/dry vacuum or brush. The crack has to remain relatively wet and not completely dry for perfect patching.
  • Mix the patch compound as directed by the manufacturer and get ready to apply.
  • Trowel the patch into the crack until it looks tight without air spaces. Fill the compound into the crack and smooth its surface to the level of the surrounding concrete.
  • Let the compound to cure as directed by the manufacturer before you paint or seal the area to match the rest of the concrete.
  • How To Tell If A Pool Is Out Of Level

    If an in-ground pool is out of level, then the movement of the pool may have caused the concrete decking around the pool to crack. In-ground pools have considerable weight and when these heavy pools shift or move, it is common to have damaged coping and cracking of the concrete deck.

    Checking to see if the pool is level will help determine if this has contributed to the concrete deck cracking. One of the easiest ways to tell if a pool is out level is to look at the water level in relation to the horizontal grout line around the pools edge. If the water level is down one inch from the grout line at point X, it should be the same one inch all away around the pool. If its 2 ½; inches low at the opposite side or end, then the pool would be a I ½ inches out of level. The tile is generally installed level all the way around the pool when it is first built, so it makes a good way to gauge if there has been movement and how much.

    How Polyurethane Lifting Foam Works: A Simple Process

    This innovative and effective fix to your driveway or walkways can be installed without interrupting your daily life or disrupting your property.

    A truck or trailer that contains the foam can be parked wherever its most convenient for you and your neighbors. An extremely long hose can be set up to transfer the foam to your property, so theres no risk of heavy trucks sitting on your driveway or blocking the road.

    Our well-trained installation will pull the hose to the area of concrete that needs to be repaired, setting it carefully in place. Well then inject the polyurethane foam through drilled holes that reach under the slab, filling any areas below, thereby raising it to appropriate levels and creating a lovely, smooth, even surface.

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    Additional Details To Avoid Cracked Tile

    As with wood floors, the best way to avoid cracks is to install an anti-fracture membrane. Isolation and uncoupling membranes work, as do liquid-applied coatings or synthetic fabrics for use over concrete. Some additional details to consider:

    Before using a liquid-applied or peel-and-stick membrane, let relative humidity drop below the required percentage as specified by the manufacturer, typically around 80 to 90 percent. This usually takes about 28 days and can be confirmed by drilling a hole in the slab and inserting a moisture probe per ASTM F2170.;

    With a liquid-applied membrane, thickness correlates directly to quality, so its a good idea to have quality assurance procedures in place that ensure that the membrane is applied at the recommended thickness.;

    Dead spots under tile sound hollow when walked on and could signal that moisture coming up from the slab is causing the thinset mortar to release. An under-slab vapor barrier and a membrane between the slab and tile should prevent this.

    When installing anti-fracture membrane over a slab, use a continuous membrane instead of just treating control joints in the slab.;

    Where tile meets a wall or other floor material, leave space for expansion and finish it with a shoe mold or baseboard.;

    Richard Baker is program manager of the Builder Solutions Team at IBACOS.

    Question: What Does Blk Mean When Marked On Concrete Flooring By A Crack

    How to Prevent Cracking in a Stamped Concrete Patio ...

    Carol said:New home construction – pulled up cracked tiles – large crack in concrete flooring with inspector markings of “blk” in two areas around crack. What does “blk” stand for?



    “blk” is not a standard building inspection abbreviation that I’ve seen. Sorry I don’t know. Perhaps you could ask your local building inspector and let me know what she or he says.

    Don’t just put down more tile without a better evaluation of the cause of the cracking and its impact.

    Continue reading at CONTROL JOINT CRACKS in CONCRETE or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

    Or see CONCRETE SLAB CRACK FAQs – questions and answers posted originally on this page.

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  • Suggested citation for this web page

    CONCRETE SLAB CRACK EVALUATION at – online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

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    Permanent Fire Pits And Concrete Cracking

    Permanent fire pits generally will cause concrete to crack over time. This means that every few years the concrete will need to be replaced in that area. There are specific additives that can be incorporated into your concrete to help prevent premature cracking. You can also add some fire resistant rock as a barrier between your concrete and pit. You will want to consult with a concrete professional before installing your fire pit to find out all of your options when it comes to installation.

    Do Fire Pits Cause Concrete Damage

    Fire pits provide a great social space to any outdoor area. They are aesthetically pleasing and come in a wide variety of styles and sizes; there are even videos showing homeowners how to build their own fire pits. With this growing popularity comes the question of how a fire pit will affect the concrete it is installed on top of.

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    What Else Will Cause Cracks In Concrete

    You know the old saying build your house on stone and not on sand or less cryptically the better the site is prepared and compacted the less likely your slab will crack, if the ground has been disturbed in any way or if you have to level the site then good preparation.

    So what is good preparation? That will depend on the ground if it is a natural state and the topsoil and grass and any weeds or old tree stumps have been removed then a layer on road-building gravel with a thin layer of sand would do the job as long as the road base material is compacted there is no need to compact the sand or fine crusher dust.

    Another thing to be mindful of is the correct placement and the use of a vibration tool to settle the concrete and leave no voids or hollows in the concrete the aim is to have a uniform thickness over the whole slab area.

    Steel reinforcement can prevent concrete cracks if the right size is used for the expected load on the concrete. A footpath or sidewalk will carry pedestrian traffic but I wouldnt want to drive a truckload of concrete over it. Sizing of the reinforcement is critical to the life and therefore the structural integrity of the concrete.

    Concrete Cracks Caused By Overloading The Slab

    How to Repair Driveway, Patio & Pool Deck Cracks Before Applying Concrete Overlay

    Although concrete is a very strong building material, it does have its limits. Placing excessive amounts of weight on top of a concrete slab can cause cracking. When you hear a concrete mix has a strength of 2000, 3000, 4000, or 5000+ PSI, it is referring to the pounds per square inch it would take to crush that concrete slab.

    When it comes to residential concrete slabs, overload of the actual slab isnt all that common. Instead, what is more likely to occur is excess overload on the ground below the slab.

    After a heavy rain or snowmelt when the ground below is soft and wet, excessive weight on the slab can press the concrete down and result in cracks. Residential homeowners who place large recreational vehicles or dumpsters on their driveways are more likely to see this type of cracking.

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    Why Does Concrete Crack

    There are several reasons why concrete cracks, with the most common being drying shrinkage. Concrete, when placed in the plastic state, is at its largest volume. As the concrete sets and hardens, it begins to shrink. On average, concrete shrinks 1/8 inch in twenty feet.

    Concrete is typically designed for compressive strength and has significantly lower tensile strength. If the internal tensile stresses are greater than the tensile strength of the concrete, a crack can develop.

    Winters And Summers Create Additional Problems

    Rain water and melting snow is a problem, especially when it runs into the concrete cracks and freezes. When water freezes, it expands, and this expansion creates tremendous pressure on the concrete resulting in damage and cracking. Over and over this process occurs in the winter and season after season it goes on, continually making things worse.

    As the summer rolls around the concrete goes from cool to hot, sometimes so hot that you cant walk barefooted across the deck. This constant expansion and contraction of the concrete takes its toll and more damage occurs. If there are not proper control joints and expansion joints in the concrete deck, then the damage becomes more server.

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    Four Types Of Cracks In Concrete Slabs & Floors

    Types of foundation cracks, crack patterns, differences in the meaning of cracks in different foundation materials, site conditions, building history,and other evidence of building movement and damage are described toassist in recognizing foundation defects and to help the inspector separate cosmetic or low-risk conditions fromthose likely to be important and potentially costly to repair.

  • Shrinkage cracks in a slab are unlikely to be of any structural concern but can be a source of water entry or radon entry in buildings and may form a tripping hazard.
  • Each type of concrete foundation, wall, basement slab, floor slab, or slab on grade crack is discussed and described with photographs below.

    Other types of concrete cracking such as due to impact or loading are discussed in other articles at this website.

    Cracks come to the job along with the concrete, riding in the same truck! At a Journal of Light Construction conference a lecturer informed us that “Every concrete truck that comes to your job to pour a slab has at least four cracks in it.

    It’s up to you to either provide control joints, or not. If you leave out control joints the cracks will occur in a messier pattern at natural stress points in the slab.”

    Can Cracks Be Stopped

    How to fix a crack in your concrete patio

    There are a few ways to stop or limit cracks. One is to place rebar into the concrete. Like most builders, we do this. Granted, it doesnt prevent all cracks. We place rebar in several strategic locations to keep the concrete from settling and pulling away from places it needs to be. It also helps lend strength to the slab.

    Also, concrete poured in the middle of the summer is going to have more cracks than concrete poured when it is colder. Why? Well, lets think about it. What does the hot Sun usually do to water? It evaporates it quickly. So during the Summer, your concrete dries out faster, producing more cracks. So if concrete is poured in the cooler months, assuming its placed on a good base, it will have fewer and smaller cracks.

    There are other ways of avoiding cracks or keeping them to a minimum, but they start getting very pricy. The cheapest of these pricy options is to fill the whole slab with steal mesh. This will still allow cracks to occur, because the concrete is shrinking around all this mesh, and the mesh might not be shrinking with it. The idea though, is that the mesh will keep the concrete from settling or from separating too badly. We do not install mesh, because its a high cost additive that doesnt fully stop cracks from occurring. And since we pour your floor on compacted fill, were not worried about settling issues.

    Naturally, this is overkill for most homes.

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    Insert Foam Tubing Into Large Cracks

    The crack I had to repair was about 1/2 inch wide.

    Although Sakrete crack filler can be used for cracks up to this size its best to fill in large gaps with the foam tubing.

    The foam tubing should be slightly wider than the crack to create a tight fit. I used a 5/8 inch wide variety.

    Place the tubing in the crack and push it down. There should be a 1/4 inch space between the top of the foam tubing and the top of the concrete crack.

    This 1/4 inch space is where the concrete crack filler will be poured.

    Click on this link for more details on the polyfoam caulk saver.

    Its made by Frost King who also has a ton of other great weatherizing products.

    Check out their website because youll get a lot of great ideas of how to keep the cold weather from increasing your heating bill.

    Some Other Preventive Control Measures For Cracks In Concrete:

    • Applying good acrylic silicone sealer yearly to concrete works
    • Avoid calcium chloride admixtures
    • Prevent extreme changes in temperature.
    • Consider using a shrinkage-reducing admixture
    • Warm the subgrade before placing concrete on it during cold weather
    • Consider using synthetic fibers to help control plastic shrinkage cracks.

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    Add Solid Crack Filler

    Assess the depth of the crack. If the crack is partially or completely deeper than 1/4-inch, fill in the necessary sections to bring it up to that height. It is not desirable to use the liquid crack filler for deep areas as this extends curing time, can result in sinking filler, and adds to the overall cost of the project.

    One way to add solid filler is to dispense clean sand by hand through a funnel. One hand holds the funnel, while the other hand holds a small amount of sand and slowly drops it into the funnel. This method has the advantage of being very inexpensive and allowing you to vary the height of the crack filler as you go.

    Another option is to force a closed-cell backer rod into the crack. Three-quarter-inch backer rod is designed to fit into 1/2-inch cracks. Force the backer rod into the crack as much as you can with your fingers. Cut off the backer rod when you reach higher areas that do not need filler. If you reach sections where it is difficult to press the rod with your fingers, use a blunt tool such as a paint stirring stick, since sharper tools like screwdrivers may pierce the rod. Make sure that the backer rod is firmly in place before proceeding to the next step.

    Why Does Concrete Buckle In Heat


    Concrete expands when it gets hot, and when the concrete has nowhere to go, it buckles. The technical term is called thermal expansion. You may have heard the term expansion and contraction before. Almost all building materials will expand when they get hot and contract as they cool. Simply put, this means they grow a bit in heat and shrink when they cool. And concrete is no different. Heat causes concrete to expand as the material heats up and this expansion has to be accounted for during construction.

    Concrete buckling can be caused by a difference in temperature throughout a concrete structure or by a rapid temperature change. Heat will expand concrete while an uneven temperature will create tension. But both warm temperature and variances in temperature can result in buckling.

    Concrete is one of the most commonly used building materials in the world for both commercial and residential projects. One of the biggest issues when working with concrete is buckling, but why doesnt all concrete buckle in the heat. Its mainly due to relief cuts being used which allow for some expansion and the aggregate thats been used. Some aggregates expand a lot more than others so this should be accounted for in your design.

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    Preventing Tripping Hazards: The Solution

    High density polyurethane concrete lifting foam helps fix sinking, moving and cracking concretemaking it an ideal way to repair uneven surfaces and eliminate tripping hazards.

    This specialty foam gently elevates concrete slabs or other damaged surfaces, restores its stability and structural integrity, and provides a moisture barrier between the soil and the concrete. Steps, sidewalks, residential driveways, slab floors, pool decks, and other concrete with cracks and uneven areas are all capable of receiving this easy, quick treatment.


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