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Water damage concrete slab

Slab leak water damage happens more often than you might think. It's hard to imagine a concrete foundation developing leaks, but many factors can result in water under your home's slab. Pipes underneath slab foundations can crack in the wintertime and cause water damage In older houses, material age plays a big role Any water damage is often accompanied with a bad smell that cannot be located. The same is true when a concrete slab leak occurs. As moisture begins working its way up through the pores in a concrete slab, the water content can build up and allow mold and mildew to grow at the foundation of your house Concrete foundations are porous, and water fills in any pores it can find. Over time, the water can seep into the concrete foundation and ultimately break down the concrete. This break down will cause the foundation to crack, which will in turn cause foundations to shift and the home to become unsettled An issue you can run into with concrete floor water damage is that water-based adhesives will not cure properly. As water-based adhesives have become more popular, this has become a bigger issue when dealing with restoration. Since moisture evaporates from the concrete, the water-based adhesive absorbs it

Under Slab Vapor Barrier - Americover

Moisture and Water Seeping through a Concrete Slab Floor Water seeping through concrete floor is more common than you think. It's frustrating and annoying and that's the danger. It's not enough that you treat it as a frustration and annoyance The excess moisture can ruin a floor that uses a water-based adhesive to attach to the concrete, causing the floor to shift and slide around. And if your basement’s concrete isn’t restored promptly, it can become a hotbed for mold growth, which can pose a serious risk to your family’s health The primary source of moisture in a concrete slab is the proportion of water mixed with the cement. No water source has a greater impact on the time it will take concrete to dry. Yet you have other water sources to worry about. A variety of potential external water sources at a worksite can affect slab drying and curing Concrete can deteriorate for a variety of reasons, and concrete damage is often the result of a combination of factors

How To Prevent Foundation Damage To Your Home - YouTubePouring Placing and Finishing Concrete in Cold Weather

Slab Leak Water Damage: 6 Things You Need to Know

Slab foundations can crack and drop, causing damage to floors and interior walls. This damage occurs when a void develops under the floor, which can happen for one of 3 reasons: 1. Shrinking Soil - Much as a full-basement foundation can drop when soil dries out and shrinks, this is also a common affliction for slab foundations Pond curing is another great way to cure concrete, and the process is just as it sounds: You form temporary berms around a new concrete slab, and then flood the area inside them with one foot of.. Water damage to concrete has many causes. The most common culprit is flooding, although this flooding can be the result of anything from a natural disaster or broken pipe. Here are a few other common causes of water damaged concrete in today's households Water or water vapor rising out of a concrete slab on grade can cause flooring to lose adhesion, to warp, and to peel. Beneath continuous flooring, moisture can also cause ripped or separate seams, air bubble efflorescence deposits, and other deterioration When a concrete slab has been affected by water, foundation repair may be required. If you have concerns, be sure to deal with this type of problem in a timely manner. It pays to avoid foundation damage and costly repairs later

5 Symptoms Of Concrete Slab Failure - & When To Hire A

A damaged concrete surface will obviously also invite more water in and then comes the freeze-thaw cycles. In fact, freeze and thaw cycles aggravate the damage and lead to cracking. Thus, the Effect of Rain on Concrete will cause it to lose surface strength, giving rise to more issues in the future. #3. Concrete Scaling Water pooling on the surface around the perimeter of the house eventually degrades concrete and mortar foundations. The most frequent cause is landscaping that slopes toward the house, instead of away. This causes rainwater to pool close to the house where it seeps down into the foundation

How Standing Water Damages Cement Foundations - GGNC

  1. While concrete continues to cure and harden for weeks or months after it has been poured, the new pour is most vulnerable to rain, frost, or water damage when the pour is very new - from the time right after the pour has been completed, for perhaps 24 to 48 hours
  2. When exposed to rainfall, freshly-poured concrete may show delayed signs of damage overtime. The excess water in the slab creates a high water-cement ratio that reduces the concrete's durability. One case report revealed that degradation of reinforced concrete structures starts in rainy and winter seasons
  3. Drying Water-Damaged Concrete Slabs Should Be Easy, But It's Not When a broken water main flooded the strip mall, the property owners knew clean up and restoration would take time. And it did: six weeks of mopping up, refurbishing contents, removing soaked drywall and flooring, and replacing building materials
  4. Concrete degradation may have various causes.Concrete can be damaged by fire, aggregate expansion, sea water effects, bacterial corrosion, calcium leaching, physical damage and chemical damage (from carbonatation, chlorides, sulfates and non-distilled water).This process adversely affects concrete exposed to these damaging stimuli
  5. The Damaging Effects of Water. Another cause for sinking concrete is water intrusion. Water that is constantly intruding below the slab will overtime erode or wash away the soil or stone base. Clay rich soils will compound the effects of water intrusion and settling as the clay will freeze and expand during cold weather and shrink when it heats.
  6. No, water isn't going to soak up like a sponge, but concrete does allow water to seep through when there is enough. Concrete also cracks, and those cracks will be the first routes of seeping water as it leaks through the slab
  7. or, the concrete is still wet enough and the surface required is a brushed finish anyway it might be possible to brush in a bonding compound to consolidate the surface - obviously this will leave a brushed-finish to the slab so might not be ideal if you need a perfectly smooth surface

A slab leak happens when the concrete slab has cracked in places due to water damage. The blame can be placed on faulty plumbing below the slab. When this issue manifests itself, the water pressure may become unsatisfactory, and the flooring may turn soggy A slab is another name for the concrete foundation some homes are built upon. Water and sewer lines often run below the slab. A slab leak can result if those lines break or deteriorate and release water under your home's foundation. Are Repairs Covered By Homeowners Insurance When the ground freezes, so does the water trapped within your concrete slab. As this happens, it expands and puts pressure on the slab from within. This compromises the slab's structural integrity and leads to damage. Once the weather warms up and water in the slab begins to melt, the concrete can flake and crack Miami condo workers suspended repairs last fall due to concrete damage: report rebar under the pool as well as standing water in its slab thickness based on the core data seems to be at.

Concrete Floor Water Damage Repair: An Overview of the Proces

Water Seeping through a Concrete Slab Floor Contractor

Who is responsible for water damage and repair under concrete slab floor? Illinois. I live in a condo that is on a concrete slab floor. The water lines are underneath the floor. In case of a leak, in one of the lines who fixes it, me are the association. Illinois. Please drag open the comment box from right bottom corner to make it larger A concrete slab on grade is a flat area of concrete poured directly on the earth or water membrane. Broken leaky pipelines in your homes foundation or slab are nothing to sneeze at. New Concrete Foundation Or Slab Freeze Damage Oct 11 2013 by matthew stock. Water damage concrete slab. Before pouring the slab the homes sewer and drain lines are. What are the signs/causes for water seeping up through concrete slab? There are a number of signs or causes for water seeping up through concrete slabs. For example, you wet or damped carpets would reveal that there is some issue like this. Furthermore, your wet concrete slabs will indicate that there is some underground water issue

How to Restore Concrete Affected by Water Damag

Moisture Problems Between the Flooring and the Sla

In the Dallas, Fort Worth metroplex, wet slab foundation drainage issues and prevention is an important topic. If you're a homeowner, it's worth studying. That's because a moist concrete slab can indicate drainage problems. Excessive rainfall can ultimately cause slab foundations to become wet and heave. That may result in structural damage The colder the temperature, the deeper the soil will freeze. Frost forces can lift a foundation dramatically - sometimes by several inches - leading to serious heave damage. Plumbing leaks: Leaks or breaks in plumbing lines that run underneath a concrete slab or through a foundation wall can deposit moisture underneath the foundation and slab. Concrete slabs will expand when flooded. Unlike ceramic tile, concrete will shrink back to its original size as it dries. This means in a water damaged tile situation involving ceramic tile installed over a concrete slab, both the ceramic tile and the slab will expand There is retained water under my house slab foundation (no basement). The moisture from this water caused some damage to the hardwood floor that caused me to dig up and see what the issue was

Shell Busey shows you how to install a drain next to a driveway to allow water to drain away from the house and yard to prevent damage during heavy rainfall... Troweling or otherwise attempting to finish the water into the concrete results in a rough, powdery layer forming on top of the concrete that is more likely to crumble and crack than properly cured concrete. Most damage done to concrete by rain can be fixed by removing the affected layer with specialized tools Frozen moisture under the surface can also cause larger sections of a concrete slab to lift at the joints, allowing for even more water and debris to enter underneath and cause greater damage. Severely lifted pads deserve immediate attention as they can be considered a safety hazard for pedestrians and individuals in wheelchairs, and can.

Leaving this sign of a slab leak unchecked could lead to potentially irreversible water damage. The normal pH of water should be between 6.5 and 8.5. 4. Abrasion. Abrasion is another common cause of slab leaks. When pipes, during the regular course of their use, rub against concrete, gravel, other materials, or other nearby pipes, the constant. Reading time: 1 minuteDifferent types of defects in concrete structures can be cracking, crazing, blistering, delamination, dusting, curling, efflorescence, scaling and spalling. These defects can be due to various reasons or causes. Contents:Causes for Defects in Concrete StructuresStructural Defects due to Design and Detailing Structural Deficiency due to Construction Defects Other. Slab foundations. Concrete slab foundations usually suffer the least damage in floods, however, the structure sitting on top of them may suffer considerable damage. Erosion and under cutting (which is a form of erosion), can undermine the supporting soil of the slab

A slab leak is an industry term for a leak within the waterline piping below a home's concrete floor, and they can occur in homes and buildings of all ages. Broken water pipes under your home can cause irreparable damage to foundations and cost tens of thousands of dollars to repair Repairing rain damaged concrete. A concrete floor dusts under traffic because the wearing surface has been weakened, normally as a result of water damage whilst finishing. Depending on the severity of the damage, a surface densifier or concrete hardener can be used to harden or densify the surface After the water seeps into the concrete slab via tiny cracks, it freezes in the joints. After that happens, the moisture begins to expand at a rapid pace - by approximately 9%. Now what that does is exert a tremendous amount of pressure on the material leading to crack formation and rupture It's expensive to fix, and you can't simply repair damage that is this extensive - you need to replace the damaged reinforcement and concrete, she said. The report from October 2020 said repairs were not possible for multiple reasons. One was that the images suggested damage extended into the thickness of the wall around the pool Updated May 6, 2020. Cracks, settlement, and other types of damage to your concrete foundation are not only serious to the structural integrity of your home, they can also be very expensive to repair. Depending on the extent of the damage and the method of repair, you could be looking at a bill of up to $15,000 (See: Foundation Repair Cost )

Video: How Structural Damage Happens to Slab Foundations U

Foundation damage can spread quickly when structural components (or the soil holding them up) become compromised by accumulating water. How does the under-slab leak repair process work? Foundation repair specialists who are experienced with concrete slabs know how to search for and isolate the source of hidden water leaks Foundation damage is one of the most significant and costly mishaps that can happen to a home. A few cracks, an unsettled base, or weak concrete can add up to severe and expensive repairs. When you have a foundation problem, you'll know from the ensuing damage, but it's best to avoid the issue altogether by being familiar with the biggest threats to your home's foundation Efflorescence Damage Concrete - Not Usually a Problem. Efflorescence is a white powder created when saltwater evaporates from a masonry surface like concrete. It's a very common problem in cold climates on garage floors. Rarely will it cause a problem inside of your garage. The first thing to remember is cars carry in snow and ice slush on the.

Concrete slab foundations are more common in states with warm climates where the ground is less likely to freeze and cause the foundation to crack. There are good reasons for building or buying a. The structural survey report detailed damage to a concrete slab below the pool deck, cracks in the parking garage, 'major error' in waterproofing and other problems In lower temperatures, this extra water adds additional ice to the concrete upon refreezing, which adds hydraulic pressure to the concrete. However, good quality concrete is more resistant to salt damage. If further protected with an effective sealer like Saltguard, Saltguard WB, or Saltguard VOC you can easily prevent salt damage to concrete SURFSIDE, Fla. (AP) — The oceanfront condominium building that collapsed near Miami had major structural damage to a concrete structural slab below its pool deck that needed to be. Frost heaves or expansive soils damage to building floor slabs can range from minor to extensive in buildings depending on soil and weather conditions, site preparation, and slab construction details, as we elaborate here. The photograph above shows a rather straight crack across a garage slab near the garage entry door

Epoxy coating prevents slab leaks, pinhole leaks and pipe corrosion, helping you avoid costly water damage to your home's slab. Avoids Damage to Your Home's Walls, Floors, and Ceilings Not only is repiping a house built on a slab costly, it can result in ripping out a home's walls, floors, and ceiling A concrete slab that's damaged by corrosion can be prone to a type of failure called punching, in which the column punctures the slab and weakens the overall structure, Abieyuwa Aghayere. The slab repair specialists will use epoxy pipe liners to seal the broken pipe. They will do a camera inspection to see the extent of the damage. If trenchless repair is viable, they will clean the pipe, place the epoxy pipe liner and inflate it, and then let it cure. The entire process can be completed in a few hours

Slabjacking is a quick and simple fix for concrete damage. The repair involves drilling a few small holes in the damaged concrete, then pumping a cement slurry down into the ground underneath. The mixture fills air pockets within the soil, creating pressure and lifting the slab back into place. Once the cracks and drilled holes are caulked, the. When replacing the damaged concrete, it is wise to add steel rebar reinforcement and dowel it into the existing concrete for support. If there are large areas that are damaged and it appears that there is no reinforcement in the slab, then consideration should be given to replacing the entire garage floor A quick look at the lining process for rusted away slab ductwork. We coat the damaged areas from the registers through all the turns and into the plenum 1. Water from an appliance or plumbing link should not damage a concrete slab though trapped water will damage most laminate floors. 2. If you think you have an appliance problem you need to have that addressed or regardless of any repairs you make to the floor, the problem will continue It's also important to verify whether the basement is suffering from vapor emissions through the concrete slab. This occurs when water vapor moves up through the slab and into the room above. If the basement is carpeted, the moisture can become trapped and lead to mold growth. See our page on basement mold for more info

Slab leaks can cause water damage to a home or businesses structure and possessions. Slab leaks can also cause mold or mildew throughout the property, not only damage a home's foundation but cause health issues as well. Detecting a Slab Leak. The best way to deal with a slab leak is to recognize the signs of leak Putting rigid insulation under the concrete slab is a great way to ensure that your new space will be energy-efficient for as long as it stands! It's required for many new structures to meet code, and it can also protect the concrete from water damage. To ensure that the foundation of your home isn't a major source of heat loss, you should. Moisture in concrete can come from two main sources. The first is the volume of water used to mix the cement into concrete. Second, external sources of water may be an issue, such as water that can migrate from the ground to the concrete slab in the absence of a vapor retarder. Both evaporating water and pooled water can interfere with a stain.

Water Leaks Shreveport, LA | Mike Tilton Quality Plumbing

Waterproofing the concrete. When a leak is found in the basement, it often points to a waterproofing issue. Therefore, to prevent water from seeping into the concrete and causing irreversible damage, it will be necessary to determine the source of the problem before working on the foundation Answered by LCD: To pin down where this water is coming from, you would have to catch it early in a rain, or look for flowlines on the floor maybe showing where it is coming from. Possible sources: 1) leak in siding so water is running down in wall and out onto slab - solution is find and fix leak. 2) buildup of water from direct wall runoff or roof runoff or gutter downspouts which do not. Two days before condo collapse, a pool contractor photographed this damage in garage. There was standing water all over the parking garage, the contractor, who asked not to be named, told the Miami Herald. Cracks in concrete, exposed rebar and wet floor in the pool equipment room of Champlain Towers South, in photos taken just 36 hours. The structural engineer, Frank Morabito, detailed a litany of issues in his nine-page report, from water penetrating cracks in balcony tiles to major damage to concrete structural slabs below the.

1) Repour the slap with proper drainage. 2) Prevent water from getting onto the slab. 3) drill a 3/8 hole all the way through the slab in the lowest spot so the water will drain into the ground. into the hole to prevent ants from forming nests under the slab). A commercial pool contractor who inspected the pool area on June 22 noted cracking concrete and severely corroded rebar under the pool as well as standing water in the pool equipment room, the. Prevent excess water in concrete mixture since it leads to concrete spalling. Repairing Process of Spalling of Concrete Repair of concrete spalling vary based on severity of the damage, type and location of concrete structure. It should be performed based on recommendations of applicable codes such as ACI Code and BS EN 1504. 1 The mains water was disconnected and drained , the central heating and all other water devices stripped out /drained , no water to or in the property the whatsoever except what has been absorbed by the floor slab. No drying took place till the floors were re screeded and the plastering was done The problem is, most concrete reinforcing rods are made of bare steel that's prone to rust from water that sneaks into the concrete. When steel rusts, it expands, causing the concrete to flake off and come apart under internal pressure. This is why corrosion-proof reinforcing rod should be used for long-term reliability of concrete projects

A slab leak can eventually cause the foundation to move, rise in different areas of the house or crack. leak comes from the pipes under your yard, water can ruin your landscaping or grass. It may even flood your yard. If you have a pool, a water leak under slab can structurally damage it too. A slab leak is something to take seriously Concrete, or cement, can affect soil pH when acidic rain or irrigation water falls on a concrete sidewalk, driveway, or building foundation and sheds onto adjacent soil It has been established that rapid drying of concrete will cause cracks in floor slabs. Concrete curing is a process that allows water elimination in a controlled manner. If curing is improperly done, the water evaporation will leave hairline cracks in the concrete slab. 6 Types of Cracks in Concrete Slabs

Curing Concrete Dos and Don'ts - Bob Vil

Unpredictable summer thunderstorms can wreak havoc on a concrete pour.Rainwater can cause a new concrete surface to become soft, which in turn decreases the abrasion resistance and strength of the concrete, while increasing the tendency for dustin g and cracking to develop. The key to preventing damage to the concrete surface by a rainstorm is proper preparation and timing A slab leak is a break in a pipe that runs beneath the concrete foundation of your home. When the pipe breaks, water seeps into the ground and your home's foundation. Slab leaks can occur in either water or sewer lines. Slab leaks cause costly damage, so early detection is important In the case of concrete, slabs installed less than one year ago are more likely to be damaged than older slabs. This damage is often caused by choosing the wrong nozzle, using higher pressure than necessary, holding the wand too close to the surface of the hardscape or directing the spray at the same place for too long

The Effects of Fire on Concrete. As we discussed in our last blog, there are often multiple types of damage to the building materials.An understanding of the mechanical and physical properties of the building materials and the effects that heat has on those properties are important aspects of the damage assessment A top 10 percent slab leak can waste 90 gallons a day. A considerable jump in water bills is a sign that something is wrong. Cracks in the floor: If you notice the cracks appearing in the basement or slab, that could be a result of damage from a burst pipe in the slab. Noticeable moisture: With some slab leaks, there will be detectable moisture. Armorlon® Concrete Slab Floor Protection Temporarily protect concrete slabs from latent damage during construction and remediation projects with Transguard® concrete slab floor protection sheets. Damage to newly poured concrete or decorative colored floors caused by light construction traffic can be costly How to rapidly sd up concrete drying time 8 effective steps for repairing a water damaged subfloor how to dry a concrete floor after water damage 3 fast steps help with a water damaged subfloor networx water seeping through a concrete slab floor contractor quotes make your wet bat dry diy repair guide radonseal One warned of failed waterproofing causing major structural damage on a concrete slab over a garage and said Failure to replace the waterproofing in the near future will cause the extent of the.

How Moisture Affects Concrete Strength. Increased space between cement grains: Higher water-to-cement ratios result in greater spacing between the aggregates in cement, which affects compaction. Similarly, increased moisture levels reduce the concrete's compressive strength and durability. As concrete's surface area increases, particularly. Most modern homes have concrete slab foundations in which a layer of concrete is poured or placed onto a soil or gravel surface. The house is then built on this slab. Any damage to the slab undermines the structural integrity of the entire house. A slab leak is what happens when your plumbing system leaks under the concrete slab foundation

Waterproofing | Cantat Associates Inc

How to Dry a Concrete Floor After Water Damage: 3 Fast Step

This seal can get damaged and that's when problems arise. A broken seal is the most common cause of water leaking through the garage door. Take a look underneath the garage door. There should be a rubber gasket that runs through from one end to the other. Check to see if there are cracks and gaps Concrete - concrete is a porous material. It typically does not become damaged when exposed to water; however, adhesives, sealers, and other compounds will slow the drying of a wetted concrete slab. Moisture levels must be evaluated and properly addressed prior to installation of new flooring Seal the concrete. Another option is to seal up the porous surface of the concrete with a silicate-based sealant. Spread it over the concrete with a paint roller or a paintbrush and it will penetrate the holes through which water is oozing. The material will reach lime in the concrete, expand, and harden to fill in the surface entirely

The Water Below: Water Vapor and Concrete Slabs - Expert

As water levels and humidity change, ground moisture seeps up into the concrete slab. Vapor barriers, often installed under slabs-on-grade, are designed to block this moisture from entering the slab. However, in reality, breaches in the barrier or cracks in the slab can still permit water entry As the concrete hardens, water ensures it stays hydrated throughout the curing process. Once the hardening is complete, it will begin to dry out, and large amounts of water will evaporate into the air. The temperature conditions and the difference in the vapor pressure between the slab and the surrounding air both influence this drying process of liquid water to the outside through the relatively more porous concrete block and stucco than to the interior through the concrete of the slab. As the entire bottom of the wall can become wet due to this configuration, however, the concrete block and slab on the interior behind the drywal A slab leak is a leak that occurs in the water pipes under the foundation or in the concrete slab upon which your home rests. If left undetected, a slab leak can destroy the foundation of your home. In this article, we will discuss slab leaks, the ways in which it can be detected in South Carolina and the average costs of repairs Protecting Your Slab Foundation From Water Damage. A cracked slab foundation can result in compromised structural integrity of your home. There are many reasons why concrete cracks like; Water Wears Concrete - Continued water exposure and pooling of water on concrete leads to wearing of the concrete. Constant moisture buildup within the soil.

How Plumbing Leaks Damage Concrete Slab Foundation

As the water in the concrete freezes, it expands, which puts pressure on the concrete slab from within. This causes the structural integrity of the concrete to become compromise, which ends up leading to your concrete becoming damaged Much of the damage to the concrete slab is occurring because of water infiltration. It's causing corrosion of reinforcement bars and cracking as it freezes and thaws with the seasons. Concrete Slab Cost. A typical concrete slab costs $4 to $8 per square foot with most homeowners spending between $5.35 to $6.17 per square foot, or $113 to $126 per cubic yard for both materials and installation. Your final cost will depend on the slabs size, thickness, and if you any special reinforcement such as wire mesh or rebar

Warehouse Floor Cleaning | Concrete Floor Cleaner | Titus

Effects of Rain on Concrete and How to Prevent It

The ideal way to cure any concrete is to build up barriers around the slab and flood the surface with water and if possible leave the slab flooded for 7 days to ensure a really strong concrete slab. Wetting the Concrete and covering it with plastic or a tarp to slow down the evaporation works okay but the problem is that you will have to rewet. Concrete Crack Repair Methods Use this section as a guide to determine which product you should use. Applied Technologies has been supplying the waterproofing industry since 1998 with quality concrete crack repair materials and equipment. This includes concrete cracks in foundations, retaining walls and concrete slabs. Use this page as a guide to help you Concrete Crack Repair Methods Read. Instead of slab jacking, sectional slab repair involves repairing discrete sections of your damaged concrete slab. After identifying the void under your slab, the concrete over that area can be broken up to provide access to the void. The void is then filled with sand and sealed with a concrete mixture that is level with your slab The most compelling evidence of scaling and spalling damage to concrete is basic workmanship errors. Here are the most common mistakes made by contractors that cause damage to concrete: adding too much water to make the concrete; adding water to the concrete at the job site to make it easier to place the concrete

Types of Cracks & Damage in Block Foundation Walls

Slab-On-Grade Construction - Technical Guide Deciding to build your home with a slab-on-grade foundation instead of a conventional basement or raised crawlspace foundation can greatly reduce your environmental impact during construction, and has the potential to offer significant financial savings as well.. By replacing concrete with lower-impact and better performing building materials like. Concrete sealing and coating compounds are applied to cured, dry concrete as a maintenance and repair procedure to reduce or prevent penetration of water, aggressive solutions, or gaseous media. They help to reduce or prevent associated deterioration such as corrosion of rebar, freeze-thaw, carbonation, or sulfate damage Concrete settling and foundation damage. To be fair, tree roots themselves are not the direct cause of foundation damage, though many homeowners believe they are. Instead, the changes in the condition of the soil are what actually cause most of the damage to home foundations. This most often manifests itself in the form of concrete settling Allow new concrete to cure for at least a month before applying stain. Use a plastic airless sprayer for acid staining. Metal parts are prone to damage and corrosion. For water-based stains, spray the area in circular motions to avoid pooling on concrete flooring. Remove any existing concrete sealer before applying a new stain color Concrete is a mixture of stone and sand called 'aggregate' combined with water and cementing materials. As concrete is placed and finished, the aggregate settles into the paste, causing a thin layer of paste to rise above the aggregate. The paste layer can separate from the main body of the concrete Water under a concrete slab foundation is a bad situation because it can cause one or more problems including soil erosion under the slab, compaction of soil under the slab, swelling of the clay soils (uplift) under the slab, and other types of soil movement that can cause damage to drain lines and the slab foundation of the home. The first two problems mentioned above, soil erosion and.