HomeProPlumber 

This article details 18 Signs Of A Slab Leak.  HomeProPlumber provides full service plumbing maintenance, repairs and replacements for every plumbing component in your home. We sell and install Rheem Professional Series gas & electric water heaters, and tankless water heaters.  We are near your home in Plano, Allen, Frisco, and McKinney.  We service all homes in southern Collin and Denton Counties with no additional travel-charges.

HomeProPlumber in Plano, Texas 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 (same company as American Standard) and Coleman HVAC (same company as York HVAC).

Call us today to discuss any concerns or problems you have with your HVAC System or Plumbing.  We will arrange an appointment at your convenience and offer 24/7 Emergency Service

18 Signs Of A Slab Leak

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How To Minimize The Risk Of Slab Leaks With Slab Watering (at the end of article)

Image Source: Flikr  Photographer: Scott Durnell

SHOWN: Large Under Slab Water Pipe Leak

Your DFW Slab Home’s Water Pipes Are In The Soil Under The Home. 

A Slab Leak Is Typically Due To A Leaking Water Supply Pipe Under Your Home.

 

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

• Be Sure Every Water Outlet In The Home + Outside Faucets Are Turned Off.
• Watch Water Meter To See If It’s Recording Water Usage.
• Nearly All Water Meters Have A Rotating Gauge (may be an arrow or “gear”).  It Shows Even The Slightest Water Usage (see “gear” below).
• If you see movement, watch to see if it continues for 1 minute. You could have a ice-maker filling with water.
• If dial is moving (and all water sources are off) you have a slab leak.

Photo Source: Dreamstime ID: 00126239

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

The Term Slab Leak Is Commonly Heard In DFW.   It can be caused by either a leaking Water-Supply Pipe, or a leaking Sewer Pipe under the home’s slab foundation.  This article addresses only leaking Water Supply pipes.

Slab Leaks in DFW are common.  They are caused by the home’s slab foundation moving up & down with changes in soil moisture. DFW is built upon Expansive Clay Soil. When the clay gets wet, it expands in size.  When the clay dries out, it shrinks.  The clay can dry out to the point it becomes dust.  The home’s slab foundation depends on support from the ground underneath it.  It order to ensure the soil provides consistent support, the moisture level in the soil must be kept stable. 

This Movement Is Also What Causes Foundation Damage.  The edges of the slab move up & down (more than nearer the center) due to changes in soil moisture.  The most movement is at the corners of the foundation.  The moisture level become more consistent the closer it gets to the center of the slab.  With movement on the edges and at the corners, and no movement at the center, the slab will eventually crack due to recurring movement.  This damage can largely be avoided if a Slab Watering program is in place (details at the end of this article).

 

Click Below To See What Happens With Expansive-Clay Soil With Changes In Soil Moisture:  

Expansive Clay Soil — Wet & Dry

The soil moisture becomes more stable the closer you get to the center of the slab.  Along the edges and corners, the clay soil dries out easily, then rewets when it rains.  This causes the edges and corners of the slab to rise and fall.  Over time, this will likely damage the foundation and crack water supply pipes.   This problem can be minimized with Rain Gutters + “Slab Watering”.  

Many homes with automatic lawn-sprinkling systems also provide slab watering.   The only way to know if yours does is to talk with the company who installed it, or have an inspection done by a service that installs and repairs automatic lawn watering systems.

For Homes without an automatic lawn watering system, the home must be surrounded with “Soakers Hoses” operated by timers (more on this later within this article).  The frequency and length of time slab watering must be done depends on the time of the year.  During the coldest part of winter, slab watering  is not likely needed.  During the hottest period of summer, it’s needed frequently.  Soil Moisture-Meters will advise the current level of soil moisture so the home owner can adjust the recurring watering schedule as needed.  Soil Moisture-Meters will give you immediate information on soil moisture level (more later within this article).

An Active Slab Leak Can Generate Enormous Water Bills

And May Damage The Foundation As Soil Moisture Continues To Rise

The most common type of slab leak is due a cracked or damaged Water-Supply Pipe.  As with most components within a home, Water-Supply Lines are subject to deterioration due to aging and can wear out or fail.   Often though, Water-Supply Line Slab Leaks are caused by a cracked water pipe due to Slab Movement.

Most DFW homes have a concrete slab foundation.  However, some homes are “Pier & Beam” which means the house sits upon piers driven into the ground deeply enough that they won’t rise or fall with changes in soil-moisture.   However, with Pier & Beam the soil can get so dry that the piers may shift (side to side) at the top.  Pier & Beam homes may require less watering, but they must be watered too.

What Exactly Is A Water Pipe Slab-Leak & Why They Occur

Most water pipes are near the edges of the home.  As shown above, the concrete is tight to the pipes where they rise through the slab.  If the slab is allowed to rise and fall, the the water pipes move up & down too.  If the water pipes are metal, this movement may eventually cause a “stress-crack”.  It’s much like bending a paper clip back & forth — eventually the metal will fail.

NOTE:

• Most newer homes have flexible Water Lines.  These lines are able to move (to some extent) with slab movement.
• However, these homes’ have rigid plastic (PVC) Sewer Pipes that will crack if enough slab movement continues to occur.

Shown: PEX Flexible Water Tubing

Shown: PVC Rigid Sewer Pipe

 Signs You May Have a Water-Supply Pipe Slab Leak

• Water bill will suddenly rises or spikes.
• Water pressure appears to have dropped.
• Damp or molded carpet.
• Recent cracking in hard tile flooring.
• Bucked or cupped laminate or hardwood floors.

Photo Source: Dreamstime ID: 42657777

Shown:  Warped Wood Floor Due To Moisture Coming Through Slab from Slab Leak

• Drywall Cracks caused by slab movement.

Click Here To See An Extreme Example Of Drywall Cracks:  Drywall Cracks

• Interior doors that stop closing right, stick or bind.
• A musty odor (it’s likely mold or mildew caused by excessive moisture).
• There is a visibly damp area in the concrete floor.

Photo Source: Dreamstime ID 1130844

Shown: Damp Concrete Floor And Molded Drywall Due To Slab Leak

• A puddle of water on the floor inside the home.
• Water against an exterior wall outdoors

Click Here To See Water Outside A Home That Is Evidence Of  A Slab Leak:  Water Outside Home From Slab Leak

• You might be able to hear water movement sounds or hissing.

If The Slab Leak Is On A Hot Water Line:

• You suddenly start running out of hot water when consumption has not changed.
• Water heater is running more than usual or always running.
• Somewhat increased energy bills.
• Warm spots 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

• In winter, a cat or dog is spending time in a new location — they found the warm spot where a hot water pipe is leaking.

 

Slab Leaks Must Be Repaired Promptly To Prevent Slab Damage 

Water Pipe Slab Leaks are not something to be ignored, or left until a later time.  The water added under your DFW home (from the leak) will cause the expansive-clay soil under the house to increase in size.  As this occurs, the soil below your home will exert increasing upward pressure on the slab. Over time, the increasing upward pressure can heave the slab upward which will result in a crack.

The concrete is likely to crack along the heaved area.   It’s common that one side of the cracked slab will be higher than the other side.  The higher side is where the soil has expanded due to the slab leak.

Photo Source: Dreamstime ID 63049019

Shown: Heaved and Cracked Concrete At The Location Of A Slab Leak

 

How Water-Supply Pipe Slab Leaks Are Repaired

Find The Leaking Water-Supply Pipe

Different plumbers will use difference 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 your water-supply pipe to remove any 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.

There Are 2 Ways To Gain Access Under The Slab Foundation 

1. Bursting Through The Slab From Inside The House

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 The Steel Reinforcement 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.

Problems With Bursting Through A Slab

• In most cases, residents must move out of the room, or the entire house.
• If the work can be contained to one room, there are still times when a resident likely won’t want to be there, such as when jack-hammers are operating.
• Glued down floor coverings are damaged or destroyed.
• The home is exposed to any mold spores or gasses trapped under the slab.  For a sewer pipe slab leak, the home is exposed to bacteria and germs in sewage.
• The Slab Was Designed & Built To Be 1 Piece.  It Was Never Intended To Be Cut.

Newer DFW Homes Have Post-Tension Cable Slabs.  Cutting Through A

Post-Tension Cable Can Cause Injuries & Require Expensive Repairs

Image Source: Dreamstime 17314786

Shown:  This Post-Tension Slab (see criss-crossed cables) Is Ready For Cement To Be Poured

Post-Tension Slab Homes Have A Warning (often stamped into concrete) Never To Cut Or Drill

Click Here To See A Sample Warning Not To Cut A Post-Tension Slab: Post-Tension Slab Warning

 

2. Tunneling Under The Slab From Outside The House

Image Source: Dreamstime 80454143-1

Shown:  Tunnels Dug Under The Home For Water & Sewer Pipe Repair Or Replacement

Benefits Of Tunneling Under The Slab

• No Risk Of Cutting A Post-Tension Cable
• Residents can typically live in the house while the work is being done.  All the work is outdoors and under the home.
• No floor-coverings are destroyed.
• The home is not exposed to anything toxic under the slab (such as mold or gasses).
• The slab is never cut.  It remains in one piece, just as it was: designed, built, and intended to always be.

 

Slab Watering To Minimize Your Home’s Slab Foundation Movement

In Many Cases, A Slab Leak (Or Foundation Crack) Could Have Been Avoided If  The Soil Moisture-Level Around The Edges Of Home Had Been Kept Stable  Slab Watering Also Reduces The Risk Of Needing Foundation Repairs.

Click Below To See Images Of What Occurs With A Concrete Slab When Soil Moisture Is Not Maintained

Slab Bending Due To Drying & Wetting Of Expansive Soil

This occurs when the soil around the home becomes too wet and expands -or- becomes too dry and becomes smaller.  The closer to the center of the slab, the less the soil moisture-level varies.  Since the majority of the changes in moisture-level occur at the corners and outside edges of the slab, the slab’s movement is greater at the edges and corners.

Why slab movement can break water supply-lines or waste lines.The horizontal waste pipes are under the slab and run through the soil under the house.  The vertical pipes go up through the slab where they are connected to plumbing fixtures above the slab.  If the slab bends, it puts upward or downward pressure on the water & & sewer pipes.  Over time, they may crack and a slab leak occurs.

When the slab moves up or down (due to soil moisture-level changes):

• The vertical pipes (attached to plumbing fixtures inside the home) move up and down with the slab.
• The horizontal pipes don’t move (because they are located within soil).
• If the slab movement is enough, the pipes can crack due to the upward or downward pressure the slab-movement creates on the pipes.  The older the pipes become, the more likely they are to fail under slab-movement pressure
• NOTE: This same movement is also what creates the need for many foundation repairs in DFW..

How To Minimize Slab Movement / Bending

Due to Soil Moisture-Level Changes

1. Install Gutters To Eliminate Water  Near The Edges Of The Foundation (minimizes large increases in soil moisture).

• This is accomplished with Rain Gutters to catch and move the water away from the foundation.  Allowing rainwater to fall right at the foundation causes tremendous changes in soil moisture-level. The more the moisture-level changes, the more the slab moves.

Shown: A Home With Rain Gutters Installed.   You can see a gutter downspout (white vertical pipe left of garage door).

• It’s equally important to install Gutter Downspout-Extensions to carry the water at least 3 feet away from the foundation.

Shown: Slip-On Gutter Downspout Extension

Click On Image To: View Product, See Details, or Purchase From Amazon.com

2. Provide “Foundation Watering” During Periods Of Hot & Dry Weather (to reduce large decreases in soil moisture-level). 

It’s important to “water” your DFW home’s foundation when the soil around the home is too dry (this is mostly during summer).   This reduces the chances of damage to the foundation and water supply lines & waste lines due to slab-movement caused by low soil-moisture around the edges of your home.   Many automatic irrigation (lawn sprinkling) systems are designed to water the foundation (if it was part of the original installation).

 

For Those Without An Automatic Lawn-Watering System

These 4 Items Can Create A Foundation-Watering System

    

SOAKER HOSE 

Click On Image To: View Product, See Details, or Purchase From Amazon.com

 

Note: Timers For Multiple Hoses Are Also Available

 

SOIL MOISTURE METER

These can be purchased at Amazon and many retailers with lawn & garden departments.   Most don’t require a battery, and all you do is push them into the ground.

 

PLANTING BEDS WITH MULCH or LANDSCAPE ROCK

Planting beds running down all sides of the home are perfect for minimizing evaporation of the water you add for slab watering.  This can also be done on grass, with the soaker hose 18″ away from the house.  The water will evaporate much more quickly however.  With a Moisture Meter, you will always know how often the slab needs water.  The hotter the temps the more watering needed.  In Nov-March, it’s less likely slab watering will be necessary if your lawn is flat.  The Moisture Meters will let you know if / when the slab needs watered during winter. 

• If you have planting beds with rock, that’s all you need. 
• If you have mulched planting beds, fill them as full as possible to minimize evaporation of the water around your home’s foundation. 
• If you don’t have planting beds, you can create them with edging, weed-barrier, and rock or mulch.

Green metal planting bed edging is common in DFW.  The problems with metal are that the paint flakes off and eventually they rust and must be replaced.  That said, they are a good option to create planting If you don’t have planting beds, they can be created by installing edging 2 feet from the edge of the house. 

 

Click On Image To: See Product, View Details, or Purchase From Amazon.com  (a 48″ tree-ring is shown)

 

There are many vinyl planting bed edging products available.  This eliminates the issues common with metal.   Spikes that are hammered into the soil to hold the edging are sold separately.

Click On Image To: See Product, View Details, or Purchase From Amazon.com (this is one of many types of vinyl planting bed edging)

Other Important Things To Know About Slab Watering

• Most (if not all) municipalities allow foundation-watering at any time on any day.  Check your City’s website to ensure you are in compliance if foundation-watering restrictions apply.
• The best time to water is at night as there is no sun, and cooler temps reduce the amount of evaporation.
• Place soaker-hoses 18 inches away from the foundation.
• Start by setting the water-timer for 2 hours each day.
• Monitor the Soil Moisture Meters to determine if 2 hours is enough.
• As the weather gets hotter & drier during the summer, you will need to increase the frequency and length of time that you water.

 

HomeProPlumber 

This article details 18 Signs Of A Slab Leak.  HomeProPlumber provides full service plumbing maintenance, repairs and replacements for every plumbing component in your home. We sell and install Rheem Professional Series gas & electric water heaters, and tankless water heaters.  We are near your home in Richardson, Garland, and northeast Dallas, Texas.  We service all homes in southern Collin and Denton Counties with no additional travel-charges.

HomeProPlumber in Plano, Texas 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 (same company as American Standard) and Coleman HVAC (same company as York HVAC).

Call us today to discuss any concerns or problems you have with your HVAC System or Plumbing.  We will arrange an appointment at your convenience and offer 24/7 Emergency Service