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This Article Details 40+ Signs That You Have A Slab Leak.  Part 2 (link provided) describes how to Minimize The Risk Of Slab Leaks + Slab Damage With Slab Watering (to maintain consistent soil-moisture along the outside edges of the house). 

Al’s Plumbing, Heating, & A/C — in Plano, TX provides full-service plumbing; maintenance, repairs, and replacements for every plumbing component in your home.  Al’s sells and installs gas and electric water heaters.  Al’s is near your home in; Plano, TX; Allen, TX; Frisco, TX; and McKinney, Texas.  We service all homes in southern Collin County, TX, and northeastern Dallas County, TX with no additional travel charges.

Al’s also provides maintenance & repairs for all brands of Central A/C, Gas & Electric Furnace, and Heat Pumps.  Additionally, we sell and install new HVAC Systems from American Standard (same company as Trane), Ameristar, and Coleman HVAC (same company as York HVAC).

Call Al’s today to discuss any concerns or problems you have with your HVAC System or Plumbing. 

We will arrange an appointment at your convenience.

Al’s Plumbing, Heating & A/C Repairs Slab Leaks. 

40+ Signs That You Have A Slab Leak

-PLUS-


Minimize The Risk Of Slab Leaks + Slab Damage With Slab Watering & Rain Gutters

Click Here To Read Our Article:

AlsPlumbing.com Slab Watering & Moisture Management


A Slab Leak Is Caused By A Cracked & Leaking Water Pipe Under Your Home

photo of underground water leak

Image Source: Flikr  Photographer: Scott Durnell

Shown: Large Under Slab Water Pipe Leak


The Fastest & Easiest Way To Determine If You Have A Slab Leak

  • Turn Off Every Faucet Inside & Outside The Home.
  • Open the City’s water meter box.

Note: The City’s water meter box is near the curb in front of the house.

Note: You may need a special tool to open it.  In that case, call the City to open the box.

  • Nearly all water meters have a rotating gauge (it may look like a triangle or “gear”).
  • Unlike the others, that gauge won’t have numbers around it.
  • That gauge shows even the slightest water usage.
  • Watch for movement for 1 minute (in case an ice-maker filled).
  • If The Dial Moves — You Have A Slab Leak.

water meter

Photo Source: Dreamstime ID: 00126239

For This Meter, The Black “Gear” Will Turn With Even The Slightest Water Usage


Slab Leaks Must Be Repaired To Prevent Further Slab Damage 

Slab Leaks can’t be left unrepaired.  As more water accumulates under your home — expansive-clay soil under the house continues to increase in size.  As this occurs, there’s increasing upward pressure on the slab. Over time, increasing pressure may heave the slab upward — and the concrete will crack along the heaved area.   It’s common that one side of the heaved slab to be higher — as the higher side is where the soil expanded the most.

cracked and heaved concrete

Photo Source: Dreamstime ID 63049019

Shown: Heaved and Cracked Concrete At A Slab Leak


How & Why A Slab Leak Can Damage A DFW Home’s Foundation 

Although concrete does a good job of containing water — water vapor passes through it easily.  In order for concrete to “cure” (dry all the way through), water vapor must be able to escape.   There’s only one-way moisture leaves concrete — from its surface.

The soil under concrete slabs is damp — with a relative humidity nearing 100%.  Without a vapor-barrier in place — water vapor would continually enter the slab from underneath.  Then, the water-vapor would migrate to the surface.  This would destroy adhesives holding floor coverings in place.  For floor-coverings that don’t require adhesive (called “floating floors”) — the water vapor would cause them to warp.  With carpet & carpet pad — water-vapor would mix with soil within them,  and mold would grow.

Source: https://www.concretenetwork.com/vapor-barriers/moisture.html

With the Vapor-Barrier in place (just below the slab) — if a slab leak occurs, the leaking water has nowhere to go.   So, the water continues to soak into the ground below the house.  The expansive-clay in DFW soil increases in size until it cannot hold more water.   If the slab leak is near the center of the house, water will migrate, until all the soil near the leak is saturated, then continue to move outward.  Then, water may accumulate outdoors along an exterior wall.

Copy This Link Into Your Browser To See Water (visible outdoors) Due To A Slab Leak:

https://www.google.com/search?q=water+along+slab+foundation+slab+leak&sxsrf=APq-WBtXGr4auviXdMCUdp9m8I90hcN4hw:1646667974085&source=lnms&tbm=isch&sa=X&ved=2ahUKEwjDwqGdrLT2AhXykmoFHeeSANQQ_AUoAXoECAEQAw&biw=1097&bih=554&dpr=1.75#imgrc=WbFcgXBP32erGM

A Post-Tension Slab Foundation Ready For Cement  

Image Source: YouTube Embedded Video Link

Shown: Slab Foundation Ready For Concrete.  The Vapor Barrier is black.

Note: The Red Lines Are The Plastic Covers Surrounding The Post-Tension Cables.


Signs That You Have A Slab Leak

General Signs:

  • Water bill suddenly rises or spikes.
  • Water pressure has dropped.
  • You may be able to hear water movement sounds.
  • A puddle of water inside the home.
  • Water against an exterior wall outdoors.

If The Slab Leak Is On A Hot Water Line:

  • You’re suddenly running out of hot water.
  • The water heater is running more than usual, or always running.
  • Somewhat increased energy bills.
  • In winter, a cat or dog is spending time in a new location (they’ve found the warm spot).
  • Warm spot in the floor.  These can be spotted with a thermal-image device.

Click Here To See A Thermal-Image Device Locating A Hot Water Pipe Slab Leak: 

Thermal-Image Device Shows Location Of Hot Water Supply Line Slab Leak

Interior Signs Of A Slab Leak:

  • Damp or molded carpet.
  • Damp or molded walls near the floor.
  • A visibly damp area on the concrete floor.
  • Recent cracks in hard tile flooring — due to rising areas of the slab where the slab leak is located. 

Copy This Link Into Your Brower To See Ceramic Tile Cracking — Due To A Rising Slab (caused by a slab leak):

https://www.google.com/search?q=slab+leak+water+visisble+outside+an+exterior+wall&tbm=isch&ved=2ahUKEwiAmq6Kq7T2AhWogmoFHfukDsAQ2-cCegQIABAA&oq=slab+leak+water+visisble+outside+an+exterior+wall&gs_lcp=CgNpbWcQAzoHCCMQ7wMQJ1D0B1j6EmCkF2gAcAB4AIABXIgBogaSAQIxMJgBAKABAaoBC2d3cy13aXotaW1nwAEB&sclient=img&ei=kicmYoAJqIWq2w_7ybqADA&bih=554&biw=1097#imgrc=EULekYpQT9QLVM

  • Bucked or cupped laminate or hardwood floors — due to moisture rising from the slab into the wood. **

warped wood floor due to moisture

Photo Source: Dreamstime ID: 42657777

Shown:  Warped Wood Floor Due To Moisture Coming Up From A Slab Leak

** NOTE:  Though the term: “vapor barrier” is commonly used — a More Correct Term is: “vapor retarder”.  A vapor barrier/retarder is technically defined as: “A material that impedes the transmission of water vapor under specified conditions.”

“Specified Conditions” for a slab foundation vapor-barrier/retarder Does Not Include a slab leak.  With a slab leak — soil moisture will reach its saturation-point, then water will appear outdoors (along an exterior wall) — near where the slab leak’s located.  With a slab leak, the amount of moisture in the slab increases.  The water vapor will migrate toward the surface.  This causes wood floors to buckle or warp.

  • Diagonal cracks in drywall — typically near doors and windows.  Areas of rising slab — causing windows & doors to move out of alignment.

Click Here To See An Example: Diagonal Crack In Drywall

  • Horizontal drywall cracks — often near the ceiling.

Click Here To See An Example: Drywall Crack At Ceiling   A rising slab under the wall causes the drywall to crack where the wall meets the ceiling.

  • Gap(s) form between the ceiling and wall.  A rising slab under the wall causes the wall to raise and creates a gap.

Click Here To See An Example: Gap Between Ceiling & Wall

  • Nail pops in wall or ceiling (a nail’s head becomes visible).  A rising wall can put on the ceiling, causing nail-pops.

Click Here To See An Example: Nail Pop — nail coming through the drywall.

  • Cracks/damage in hard-surface floor covering (like ceramic or marble).  A rising slab is cracking under the hard-surface floor covering.

Click Here To See An Example: Damaged Ceramic Flooring


Exterior Slab Leak Signs:

  • Cracks or gaps within the slab — often at corners.   If the slab is moving, it’s much more likely to crack at the originating-point of the movement.

Click Here To See An Example: Cracked Slab Foundation

  • Cracks or gaps form in the mortar between bricks.

Click Here To See An Example: Gaps in mortar indicate slab movement.

  • Cracks or gaps between brick at windows & doors.

Click Here To See An Example: Gap between window & brick indicates slab movement.

Copy This Link Into Your Browser To See Water (visible outdoors) — Coming From A Slab Leak:

https://www.google.com/search?q=water+along+slab+foundation+slab+leak&sxsrf=APq-WBtXGr4auviXdMCUdp9m8I90hcN4hw:1646667974085&source=lnms&tbm=isch&sa=X&ved=2ahUKEwjDwqGdrLT2AhXykmoFHeeSANQQ_AUoAXoECAEQAw&biw=1097&bih=554&dpr=1.75#imgrc=WbFcgXBP32erGM


WHY Water (and Sewer) Pipes Crack Due To Slab Movement

During slab construction, rigid Water & Sewer Pipes are placed at ground level (below the slab).  When cement is poured for the foundation — cement sticks to water and sewer pipes where they’re rising through the slab.  A moving slab causes the pipes to move with it.

Image Source: ShutterStock

Shown: A Slab Foundation Ready For Cement.

You can See; Water Pipes (blue & red) And Sewer Pipes (white) — that will come upward through the concrete.

If the slab rises (due to increased soil-moisture under the slab) or lowers (due to decreased soil-moisture) — water & Sewer pipes must rise & lower too.  Rigid water pipes (and sewer pipes) are not designed to accommodate recurring movement and eventually crack.  It’s like bending a paper-clip back and forth until it breaks at the origination point of the movement.

Minimize Slab Movement By Keeping Soil-Moisture (Along Outside Walls) Consistent.

This Is Done With:

  • Slab Watering. 
  • Recurring watering with soaker-hoses 18 inches from the home’s outside walls.
  • Using moisture-meters to monitor soil-moisture.
  • Change watering quantity or frequency — with changing outdoor temperatures.
  • Rain Gutters & downspouts — to drain excess rainwater away from the edge of the home’s foundation. 

Click Here To Read Our Article:

AlsPlumbing.com Slab Watering & Moisture Management



NOTE: This Section Is About Various Types Of Slab Foundations Over The Decades

To Skip The Section — Scroll Down To Next Double Lines.

Where & Why Slab Foundation Homes Began 

At the end Of World War 2 in Sept. 1945 — The U.S. had more than 12 million men & women in the armed forces.  By June 30, 1947, the number of active-duty members had been reduced to 1,56 million.

Soldiers returned home, began to marry, started families, — and wanted to buy homes.  Because few new homes had been built since the late 1920s — a huge housing shortage was created.  In an effort to build inexpensive homes FAST — “tract” homes, built on slab foundations, were created. Tract homes became a symbol of Post-WWII housing.

Tract homes on slabs began with America’s first suburb — Levittown, on Long Island, New York.  During 1947-1951 — 17,447 new homes were built there.  There were 2 floorplans to choose from.  Every home had; 2 bedrooms, 1 bath + an unfinished attic area (with stairs already built up to the ceiling).  Finishing the attic created space for up to 2 more bedrooms and a 2nd bathroom (all without altering the home’s roof).   The homes included; Fireplace, Washer, Refrigerator, and electric Range — and some had a built-in TV.  Homes were equipped with; In-Floor (heating oil) heating, Insulated, double-pane windows (+ Venetian window blinds),

The homes were around 950 square feet and priced around $7,000.  Levittown, NY homes were available only to Veterans.  Vets could get a: “VA Home Loan Guaranty Program” (today known as VA Mortgage) with $0 down and monthly payments from $58.00.   At the peak of construction, Levitt & Sons Inc. was able to complete 30 new homes per day!  This building pace was largely accomplished due to identical homes being built on slab foundations.

levittown new york aerial photo

 Image Source: Shutterstock

Shown: Levittown, NY (on Long Island) — As It Neared Completion

levittown new york aerial photo  Image Source: Shutterstock

Shown: Levittown, NY

Early Slab Foundations Construction

Levittown Style Home

Image Source: Shutterstock

SHOWN: Levittown, NY Home — Cape Cod Model

How the first slab foundations were built:

  • Created as a single piece of concrete.
  • 4 inches thick.
  • Some slabs included wire-mesh reinforcement inside the concrete.
  • Exterior beam: along the outside edges of the slab (where exterior walls are) –were thicker than the rest of the slab.
  • Interior beams (located under load-bearing interior walls) — were uncommon. 
  • Water supply pipes and sewer pipes are embedded within the concrete.

DFW Homes’ Foundations Over The Years

Prior to the 1950s

  • Pier & Beam Foundation (not slab).
  • These homes have a crawl-space under them.
  • There is a concrete beam (1-3 feet into the ground) under the outside walls of a home.
  • The homes have floor joists (what the floors are attached to) — spanning the length or width of the home (which ever distance was shorter).
  • At specific locations, floor joists were supported with piers that typically sit directly on the ground.

Note: Pier & Beam foundations are still often used in more expensive homes.

During the 1960s

  • Pier & Beam gave way to slab foundations.
  • Early slabs had little or no reinforcing.
  • Some homes have slabs reinforced with welded wire-mesh.
  • Because wire-mesh is thin and can easily move — mesh reinforcement did little to add strength.

Slabs Were Upgraded To Be Reinforced With Steel Rebar (rods)

1970's built home

Image Source: Shutterstock

  • During the early 60’s — Fox & Jacobs Homes plus some smaller home builders, moved to steel rebar inside their slabs.
  • During that time, Fox & Jacobs Homes was the largest tract home builder in DFW’s suburbs.
  • Wire mesh was replaced with steel rods/bars that are welded together (known as rebar).
  • Slabs became thicker overall.
  • Exterior beams became thicker.
  • Some foundations had interior beams (supporting interior, load-bearing walls).
  • Typical steel rebar’s tensile-strength (ability to withstand damage due to slab bending) is 40,000-60,000 pounds per square inch.

Source: http://www.inspectionnews.net/home_inspection/sub-structure-home-inspection-and-commercial-inspection/6817-change-pier-beam-slab-dallas.html

Image Source: Shutterstock

Shown: A Steel Rebar Slab (not a Post-Tensioned slab) Ready For Cement.


Beginning In The Late 1960s — Post Tension Slabs

  • Fox & Jacobs Homes, and many other DFW home builders began switching (from steel-rebar slabs) TO Post-Tension Slabs.
  • Today 90%+ of new Texas homes are built on post-tension slabs.
  • Steel “tendons” (cables) replaced steel rebar.
  • Tendons run top to bottom + left to right throughout the slab.
  • A few days after the slab was poured, a machine pulls on each tendon — creating tremendous inward pressure from all four sides.
  • The inward pressure makes the slab stronger and less prone to cracking
  • The number of interior beams (under load-bearing interior walls) steadily increased.
  • Beams’ width and/or thickness increased.

Source: https://foundationrepairs.com/common-foundation-types-found-in-texas/

Source: http://www.inspectionnews.net/home_inspection/sub-structure-home-inspection-and-commercial-inspection/6817-change-pier-beam-slab-dallas.html

Today’s Post-Tensioned Slab Foundations

Image Source: YouTube Embedded Video

Shown: Post-Tension Slab (steel tendons inside red sleeves) Ready For Cement

  • Starting in the 1960’s — Post-Tensioned slabs became common in areas with expansive/compressive soil conditions.
  • This type of soil is prevalent in Texas, and some other areas of the U.S.
  • Post-Tensioned Slabs first began in these areas — due to the upward & downward movement of the slab (particularly at corners) caused by changing soil-moisture.
  • Today, post-tensioned slab foundations are being used in all types of soil.
  • Post-Tension slab’s tensile-strength (ability to withstand slab bending) = 270,000 pounds per square inch.

tendons for post tension slab

Image Source: ShutterStock

Shown: Braided Steel Tendons Used In Post-Tension Slab.  Typical tendons are 1/2″ diameter.

Source:  https://www.structuremag.org/wp-content/uploads/2014/08/C-BuildingBlocks-Allred-Jan101.pdf


  • As Compared: Typical Steel Rebars Tensile-Strength = 40,000-60,000 pounds per square inch.
  • Steel Rebar slabs are still used in some areas that don’t have Expansive-Soil.
  • Slab construction is much less common in the northern 1/3 of the U.S.
  • The primary reason is because foundations must be deep enough to go below the frost line — to prevent a building from shifting during freeze-thaw cycles.
  • Freezing soil increases in size (when the water within it freezes).  During thawing, the soil decreases in size.

Source: https://homesmsp.com/2016/04/slab-homes-dont-minnesota-homes-need-basements.html

steel rebar rods

Image Source: ShutterStock

Shown: Steel Rebar Rods Of Various Diameters.  Typical residential slab rebar is 1/2″ or 5/8″ diameter

How Today’s Post-Tensioned Slab Is Built

NOTE: Slab bending is particularly problematic on clay soils.

  • Unreinforced concrete can withstand only its own weight.
  • Concrete has little “tensile-strength” — meaning little ability to resist bending.
  • Once force is applied (like adding weight on top of the slab) — concrete bends easily.
  • Unreinforced concrete’s strength is only 10-15% of its strength when compressed — like a Post-Tension Slab.
  • Bending can cause the concrete slab to crack — at the origination point of the bending.
  • Because steel has a high capacity to resist bending, steel is embedded (as steel tendons or rebar) inside the concrete.
  • Traditional rebar provides “passive reinforcement”.
  • This means that rebar doesn’t bear any weight or load — until the concrete has cracked.
  • So, rebar provides reinforcement only after concrete bends & cracks.

Source: https://www.giatecscientific.com/education/post-tensioning-in-cold-weather-conditions/

  • Post-tensioning provides “active reinforcement”.
  • Post-tensioning places concrete under compression  — toward the center from all 4 sides.
  • Compressed concrete is stronger– and more resistant to bending & cracking.
  • Post-Tensioning occurs before weight/load is added.

Source: http://www.builderswebsource.com/_discBT/000002bf.htm

This YouTube Video Demonstrates How Reinforcing Concrete With Steel Makes It More Resistant To Bending & Cracking

Image Source: YouTube Embedded Video Link

Today’s Post-Tensioned Slabs Specifications

Concrete:

  • Typically 6-8 inches thick — and much thicker at beams.
  • Beams are 18 — 24 inches thick & 12 inches wide.
  • Beams are located under Exterior walls AND (load-bearing) Interior walls.
  • Beams can support 15,000–20,000 pounds.

Steel Tendons:

  • Tendons are made of 7 high tensile-strength steel wires — coiled together to form a ½-inch-diameter.
  • Tendons can be 15 — 200 feet long, in 1 continuous piece.
  • Tendons are placed left to right & top to bottom throughout the slab.
  • Tendons can be placed to avoid areas with penetrations (for things like water & sewer pipes).
  • Tendons are typically every 4 feet.
  • Tendons are covered with grease — and inserted into plastic sheathing.
  • Grease allows tendons to easily slide inside the sheathing.
  • The sheathing prevents concrete from attaching to the tendons.
  • Tendons are stretched with 33,000 pounds of pressure.

Post-Tensioning Of The Steel Tendons/cables:

  • After the cement is added — the slab is left to “cure” for 3 — 10 days.

Note: “Curing” is concrete drying continuously deeper below the surface.  After 28 days — concrete is fully cured/dried.

  • Next, the steel tendons are stretched to around 33,000 pounds of (inward) pressure.
  • Stretching is done by a machine that pulls on one end of the tendons/cables.
  • The stretched tendons create tremendous inward-compression — toward the center of the slab, from all four sides.
  • Stretched tendons’ tension-strength (ability to withstand slab bending) is 270,000 pounds per square inch.

Note: Typical Steel Rebars Tension-Strength is 40,000-60,000 pounds per square inch.

Sources:

  • https://www.hunker.com/12003167/tension-vs-compression-of-concrete
  • https://www.cement.org/designaids/posttensioned-concrete#:~:text=Walls%2C%20columns%2C%20and%20other%20vertical,a%20force%20of%2033%2C000%20pounds.
  • https://pdhonline.com/courses/s131/s131_new.htm#:~:text=Reinforcing%20steel%2C%20commonly%20called%20rebar,place%20the%20concrete%20in%20compression.

The Section For Various Styles Of Slab Foundations Ends Here



DFW Is Built Upon Expansive Clay Soil

photo of cracked clay soil

Image Source: Dreamstime

Shown: Very Dry Expansive Clay Soil — That Has Shruken So Much That Its Surface Cracked.

  • When the soil gets wet — it increases in size.
  • When the soil dries out — it decreases in size.
  • Soil expansion & shrinkage causes the slab to move up and down — particularly at corners of outside walls.

Copy The Link Below Into Your Browser — To See A Sample Of Expansive Clay Soil — With Ample Moisture & When Dry:

https://www.google.com/search?q=photo+of+wet+and+dry+expansive+clay+soil&sxsrf=APq-WBvi5eHw8PGlYBwnLcJg-M8J7DYz7w:1644948901717&source=lnms&tbm=isch&sa=X&ved=2ahUKEwjokteXqIL2AhWnk2oFHXBUALoQ_AUoAXoECAEQAw&biw=1280&bih=646&dpr=1.5#imgrc=StYZgAafcdglEM


DFW Homes Are Built Upon A “Floating Slab”

WHY? To Accomodate DFW’s Expansive Clay Soil.

  • This means the slab is simply sitting on top of compacted gravel or soil.  It’s not attached to the ground.
  • Not being attached — allows the floating slab to bend up & down with changing soil moisture.

BUT

  • Excessive slab movement often causes a slab to crack — because it’s bending more than designed to. 
  • Slab movement can be minimized by keeping consistent soil-moisture along the home’s outside edges & corners.

Where & Why Slab Movement/Bending Occurs

cracked slab foundation

Image Source: Shutterstock

SHOWN: Cracked Slab Foundation

The diagonal pattern of the crack is likely due to an outside corner’s movement.

As slab damage increases — more & more signs of damage to the home appear.

The closer to the center of the house — the more stable the soil’s moisture remains.  This creates a situation where the slab’s outside edges are rising & lowering (if soil-moisture isn’t kept consistent) — while the center of the slab moves very little.

The largest amount of slab bending/movement is along the outside walls — and even more so at corners.  This is because the edges are where the largest changes in soil-moisture recur.

Because the weight of the home’s roof is mostly on the outside walls (+ some load-bearing interior walls).  With mostly brick exteriors — the outside walls add tremendous weight on the outside edges of the slab.  This weight increases the slab’s downward bending potential.

Slab Bending Terms:

  • Doming (slab is lowest along the edges) — during DRY soil.
  • Dishing (slab is highest along the edges) — during WET soil.

Copy The Link Into Your Browser — For A Diagram Of Slab Movement/Bending. 

The Diagram Visually Depicts Slab Doming & Dishing (due to changes in soil-moisture along the edges).

https://www.google.com/search?q=slab+foundation+doming+and+dishing&tbm=isch&ved=2ahUKEwj3rPzdlZb2AhXelWoFHQm0AQoQ2-cCegQIABAA&oq=slab+foundation+doming+and+dishing&gs_lcp=CgNpbWcQAzoECAAQGDoGCAAQCBAeOgUIABCABDoGCAAQBRAeUABY9S9ghjJoAHAAeACAAXSIAZMQkgEEMTcuOJgBAKABAaoBC2d3cy13aXotaW1nwAEB&sclient=img&ei=p1YWYre9Jd6rqtsPieiGUA&bih=646&biw=1280#imgrc=9Oxgm_jP1PS5TM


Common Visual Issues NOT Related To Slab Movement:

Copy The Link Below Into Your Browser To Read The Full Article About Visual Signs Not Related To Slab Movement: 

https://slabperformance.com/distress-commonly-assumed-incorrectly-to-be-due-to-foundation-movement/

Spalled Concrete At Corners:

  • Spalled (comes loose) concrete at corners of slab foundations (supporting exterior bricked walls).
  • Spalling is the term to describe areas of concrete that cracked, come loose, and fell off.
Spalling Results From:
  • Normal shortening of the concrete slab — due to the concrete curing (drying all the way to the center).
  • Expansion of the exterior walls’ bricks is due to the absorption of moisture (during times of high outdoor humidity).

NOTE: Bricks are more porous than concrete — so they absorb & lose water vapor more quickly.

Click Here To See An Example: Spalled Concrete At Corner Of Slab Foundation

“Corner Pop” — A Corner Came Off The Slab. 

Image Source: YouTube Embedded Video

Shown: A “corner pop” — a corner came loose from the slab.

Corner pop is most often a symptom of different rates of expansion between concrete & brick.   A corner pop is more likely with less separation between brick and concrete exists.

Sags & Cracks In Ceiling Drywall. 

  • These are generally due to framing irregularities, or age.  It’s sometimes due to excess load at 1 specific location.
  • It’s unusual for cracks & sags in a ceiling to be due to foundation bending.

Horizontal or Vertical (not including diagonal) Cracks In Drywalled Walls.

Foundation movement/bending causes diagonal stress patterns/cracks in drywall.  It does not normally create horizontal or vertical cracks.

Doors That Don’t Latch, Won’t Open, And “Ghosting” doors (door swings open or closed by itself).

While foundation bending may be the cause.  It’s more likely due to; loose door hinges, misaligned door frame, the door assembly (door + trim around it — known as a “Pre-Hung Door”) isn’t tightly shimmed to the hole (created for the door).

Source: https://slabperformance.com/distress-commonly-assumed-incorrectly-to-be-due-to-foundation-movement/


The 2 Typical Cracks Seen In A Concrete Slab Foundation In Texas

Shrinkage Cracks:  These hairline cracks occur as moisture leaves the concrete while it “cures”.  Without the volume of the water (once present) all concrete shrinks a little as it cures.  This causes hairline cracks.  Shrinkage cracks are so common that they’re to be expected.  Shrinkage cracks seldom requires repairs.

Settlement Cracks:  These cracks were caused by areas of the slab moving — while other areas don’t move.  Settlement cracks undermine the integrity of the slab and must be repaired.  Repair includes raising the (settled) section of concrete back to its original position.  Then additional support is installed below the slab at that location.

NOTE: When foundation repairs are performed, the slab typically returns to the correct position.  And most of the gaps will close.

Slab Damage Requires Expensive Slab Repairs

  • A Recent Nationwide List Ranks DFW #3 For Home Foundation Problems.

  • Slab foundation repairs are big business in DFW.
  • A slab foundation can move a little without damage.  But, excessive movement creates damage.

  • Many slab repairs could have been minimized or eliminated — with proper slab moisture-management.

Source: https://www.groundworkscompanies.com/about/articles/top-us-cities-with-foundation-issues/



How Slab Leaks Are Located

Various methods to determine the presence and location of a slab leak:

  • Electrical equipment sends a small current through water pipes and a “listening” device can locate where water is leaking.
  • Force air into water pipes to remove remaining water.  Then only air is escaping through the crack in the pipe.
  • The location of the leaking pipe may be found by using a sensitive “listening” device.  It locates where air is flowing out of the break in the pipe.
  • Thermal-Imaging may be used to find a hot water slab leak.


There Are 2 Ways To Gain Access To Repair Slab Leaks

Slab Leak Repair Access Method #1:

Busting Through The Slab — From Inside The House

hole cut through slab foundation

Image Source: Dreamstime ID 7780291

Show: A Hole Cut Through The Slab To Gain Access To The Leaking Water Pipe.

(The “Grid” You See Is Either Steel Rebar Or Post-Tension Slab Tendons (cables) Inside The Concrete)

A hole is cut through the slab from inside the house.  Jack-hammers break away the concrete and soil is set aside.  Once the work is done, the soil is returned and a cement patch is poured to seal the opening.

Issues & Risks That Come With Busting Through A Slab

  • In most cases, residents must move out of the room, or the entire house.
  • There are times when many residents don’t want to be home — such as during jack-hammering.
  • The home may be exposed to mold spores or gasses trapped under the slab.
  • For a sewer pipe slab leak — the home is exposed to; gasses, bacteria & germs in sewage.
  • Glued down flooring is damaged or destroyed.

  • The Slab Was Designed & Built To Be 1 Piece. 
  • It Was Never Intended To Be Cut.
  • Most DFW homes, built since the early 1970’s, have Post-Tension slabs.

Click Here To See A Post-Tension Slab — before cables/tendons are tightened:  Post Tension Slab Before Tendons Are Tightened.

(If Link Doesn’t Work — Copy This Into Your Browser):

https://www.google.com/search?q=outer+edge+of+post+tension+slab+with+concrete+cover&tbm=isch&ved=2ahUKEwjxpO7YrZb2AhVftGoFHZd8A6YQ2-cCegQIABAA&oq=outer+edge+of+post+tension+slab+with+concrete+cover&gs_lcp=CgNpbWcQA1AAWABgngpoAHAAeACAAVyIAVySAQExmAEAqgELZ3dzLXdpei1pbWfAAQE&sclient=img&ei=x28WYrGlFd_oqtsPl_mNsAo#imgrc=eW4u6TYCul7a2M


Click On This YouTube Video To See A Machine Stretching The Steel Tendons Inside

A Post-Tension Slab (to about 33,000 pounds of pressure):

(At Time: 0:51 / 1:19)

 

Once the tendons (cables) are tightened — the excess is cut off.  Next, a grout patch covers where the end of the cable is located.

Click Here To See A  (cable) Grout Patch Over On The End Of Tendon/Cable: Patch On Edge Of Post-Tension Slab.

(If Link Doesn’t Work — Copy This Into Your Browser):

https://www.google.com/search?q=residential+post+tension+slab+edge&tbm=isch&ved=2ahUKEwi8loPdsJb2AhVHLs0KHb6EAJcQ2-cCegQIABAA&oq=residential+post+tension+slab+edge&gs_lcp=CgNpbWcQAzoFCAAQgARQpB1Y_zhg4zpoAnAAeAGAAegBiAHiCpIBBTYuNi4xmAEAoAEBqgELZ3dzLXdpei1pbWfAAQE&sclient=img&ei=9XIWYvzHF8fctAa-iYK4CQ&bih=403&biw=868&hl=en-US#imgrc=ai5UnirwHFoJGM

  • The tendons/cables inside a Post-Tension slab are under around 33,000 pounds of inward-pressure.
  • If a tendon gets cut — it will retract violently.
  • If a tendon gets cut — it can damage the slab as far as the other end.
  • If a tendon gets cut — they have been known to seriously injure, or kill a person near it.

Click Here To See Post-Tension Slab Damage Due To Cut/Broken Cable/Tendon: Cut Tendon Damage To Post-Tension Slab

(If Link Doesn’t Work — Copy This Into Your Browser):

https://www.google.com/search?q=damage+to+residential+post+tension+slab+due+to+cut+tendon&nfpr=1&source=lnms&tbm=isch&sa=X&ved=2ahUKEwi-6_GIspb2AhXXlGoFHSgQCaMQ_AUoAXoECAEQAw&biw=877&bih=412&dpr=2.19#imgrc=Bo8I7VBDQe4ezM


Click Here To See The Warning Not To Cut Or Core A Post-Tension Slab: Post-Tension Slab Warning

(If Link Doesn’t Work — Copy This Into Your Browser):

https://www.google.com/search?q=post+tension+slab+stamp&tbm=isch&hl=en-US&sa=X&ved=2ahUKEwjijYPBr5b2AhUQP80KHTwLDgcQrNwCKAB6BAgBEHU&biw=868&bih=403#imgrc=GCFbwwhPCdpDdM


  • The Western Group, a company that performs post-tension tendon & concrete repairs, said:  “When a post-tension cable is cut, it’s like a .44 (caliber) Magnum gun going off.”
  • Dick Bonin has seen the destruction in vivid detail. “I’ve looked at some pictures that would scare the hell out of you.” he says, “Where the cables have come up through the concrete and gone through walls and doors.”
  • Arnie Rodio, owner of Pacesetter Plumbing in Lancaster, Calif.  said: “There’s a story about a cable bursting out of slab and slicing a guy’s foot off.”
  • “Many plumbers don’t know it’s a post-tension slab, “says Tim Downs of American Leak Detection in Santa Ana, Calif. “They come in with their saws and start cutting.”

Slab Leak Repair Access Method #2:

Tunneling Under The Slab — From Outside The House

Click On This YouTube Vido To See A Man Tunnelling Under A Slab Foundation.

Tunneling Under A Slab — Eliminates All The Issues & Risks Associated With Busting Through A Slab.



Minimize Slab Leaks RiskWith Slab Watering & Rain Gutters

Click Here To Read Our Article:

AlsPlumbing.com Slab Watering & Moisture Management

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Al’s Plumbing, Heating & A/C Repairs Slab Leaks. 

This Article Detailed 40+ Signs That You Have A Slab Leak.  Part 2 (link provided) describes how to Minimize The Risk Of Slab Leaks & Slab Damage With Slab Watering (to keep consistent soil-moisture around the outside edges of the house). 

Al’s Plumbing, Heating, & A/C — in Plano, TX provides full-service plumbing; maintenance, repairs, and replacements for every plumbing component in your home.  Al’s sells and installs gas and electric water heaters.  Al’s is near your home in; Plano, TX; Allen, TX; Frisco, TX; and McKinney, Texas.  We service all homes in southern Collin County, TX, and northeastern Dallas County, TX with no additional travel charges.

Al’s also provides maintenance & repairs for all brands of Central A/C, Gas & Electric Furnace, and Heat Pumps.  Additionally, we sell and install new HVAC Systems from American Standard (same company as Trane), Ameristar, and Coleman HVAC (same company as York HVAC).

Call Al’s today to discuss any concerns or problems you have with your HVAC System or Plumbing. 

We will arrange an appointment at your convenience.