What is slab leak?
It happens when a water pipe or connection to the wastewater system has failed under a foundation slab. The occurrence of a slab leak is usually accompanied by bad news, mainly when it is not detected on time since it can generate multiple problems, such as weakening the foundation of your home.
That is the point where you will face a full-blown catastrophe. Therefore, it is important to know how to identify a slab leak in your home.
Most slab leaks cause symptoms to be aware of as they may be occurring under your feet or above your head. For example, if you begin to notice warmer floors or moisture building up over your head on the upstairs floor, then the alarms should start ringing in your mind.
Most of the time, when we find out about slab on grade leak, they have already caused significant damage. They tend to become very difficult to detect and repair. In this blog, we will tell you:
- What can cause slab leaks?
- How to identify the slab leak?
- How to repair the slab leak?
What Can Cause Slab Leak?
A leak is a sign of deterioration in the water supply system, poor connection in the sewage system, or loss of impermeability in the lining/cladding of the walls and floors around showers.
Deterioration in the water supply system
Under-slab leaks occur when a water pipe under a foundation slab fails. The failure can be caused by:
1. The environment in which the pipes are located, such as:
- The incompatibility between the copper pipe and the type of soil (its resistivity, its pH, and its sulfur content), since this may contain something that causes a negative chemical reaction when it comes into contact with the copper pipes. This reaction is known as electrolysis, and it will happen at any time, even years after installation.
- Longitudinal stresses produced by thermal contractions and stresses caused by frost (low temperatures).
- Differential movements of the ground.
2. To the characteristics of the pipeline itself, such as:
- The mechanical properties of the materials.
- Dielectric permittivity.
- The geometry of the pipes.
- Material defect due to manufacturing.
- Thickness and diameter.
- Amount of material lost due to corrosion, and
- size and distribution of corrosion marks.
The failure modes for these characterizations are usually longitudinal perforations and cracks.
3. To operational factors such as:
- Bending stresses on the pipes due to faulty installation (trench and support bed) and other interferences such as accidental breaks.
- The water pressure inside the pipe.
- Loads of the ground, traffic, and compression force exerted by frozen water of the ground on the pipe.
Explosive breaks are generally the product of internal pressure and corrosion, while holes in pipes tend to be caused by corrosion.
In PVC plastic pipes (polyvinyl chloride), they tend to have joint failures due to the loss of property of the glue in pipes that conduct hot water.
Connection defect in the wastewater system
In the bathrooms, there is usually permanent humidity. Underwater leaks occur when the sewage pipe under a foundation slab has a connection defect in the toilets/drains, particularly in WC.
This failure is usually caused by the waterproofing seal’s loss or property loss of the waterproofing material. These faults are difficult to detect, mainly if they occur at the ground/ground level in a home or property built on a foundation.
In properties with two levels or more, this defect is usually visible on the lower level when moisture is observed on the walls and ceiling.
Loss of waterproofing in the lining/cladding
The third cause of leakage usually occurs, as in the case described above, in the bathrooms. Many believe that ceramic tiles are waterproof. This is only partially true since moisture can penetrate the substrate through the joints.
The loss of impermeability in the ceramic or similar lining/coating results in moisture damage to the structure that can be solved by placing adequate waterproofing.
How To Identify The Slab Leak?
Any leakage causes signals that appear depending on how and where they occur, some more quickly than others.
1. What should you do? Look for the following signs:
- Check the taps and appliances that use water on your property for leaks.
- Look for some mold/mildew accompanied by its characteristic odor.
- Check if there is a considerable increase in your water bill.
- Look for puddles of water, damp carpets, or warped wooden floors.
- Check if the water installations become less potent.
- Touch the ground for hot spots.
- Check if the water heater is always on.
- Look for cracks in the foundation that indicate a sewer leak.
We suggest you always stay alert. Try to keep your appliances airtight, and don’t stop paying attention to your water bill. Only then, in case of an unexpected increase, will you be able to realize it immediately and will pause to identify the source of the problem in time.
Include your cat on your alert radar; check the areas where he usually sleeps. Cats look for warm places to snuggle, and their favorite place may be directly over a hot water leak, touch the ground to look for hot spots.
2. How to check for a water leak?
Generally, the water that reaches your property goes through a meter and a set of faucets.
2.1. Find the house’s water meter. This is usually located on the sidewalk or within the garden that surrounds the house. If the meter cannot be found, call your local public facilities office for information on where to locate the meter in your area.
2.2. Find the main water shutoff valve. In cold climate regions, the valve is usually located inside the house in places like the basement or garage. In hot climate regions, the valve can be on the pipe near the water meter or on the same pipe next to the house.
2.3. Turn off the taps and turn off any appliances that use water. Previously, make sure that appliances that use water, such as the washing machine and dishwasher, are not on because if one remains on, cutting off the water flow may damage it. Turn off all the taps in the house so that you can detect signs of a water leak in the water meter.
2.4. Check for activity on the water meter. Using safety gloves, remove the cap from the water meter. Depending on the make and model, each has a method for monitoring water use. Can be:
- Clock-like hands covering the meter.
- A leak gauge such as a small triangle, steering wheel, or another object.
- An odometer, a row of numbers.
With taps closed and appliances turned off, check for plumbing leaks by looking at the meter:
- Considerable movement in hand over several minutes.
- A leak indicator that will not stop rotating.
- An odometer whose numbers keep increasing.
2.5. Certify, Close the water flow to the house. If there are two valves, close the one closest to the house and don’t move the connected valve on the street side.
- Open a faucet away from the water valve to make sure the water flow is closed.
- Repeat the previous step. The meter should show the same behavior.
How To Repair The Slab Leak?
Although some plumbers offer free screening services, others can charge up to $ 400. If you suspect that you may have a leak in your home or property, we suggest you do one of the following as soon as possible:
Call a local water leak detection company online immediately before it is too late; make sure he’s a pipe repair specialist.
We suggest that before committing to a plumbing company:
- Call other plumbing companies and ask for repair estimates.
- Simply discuss the problem as it was described to you.
- Once you have several written estimates, choose a plumbing company that seems reliable and offers its services at a reasonable price.
- Verify that they have certified, legally operating plumbers with good online user reviews and that you mention leak detection or repair directly on your website, indicating that you have experience.
- Verify that they offer a guarantee of its work and have immediate attention.
- Expect to pay about $ 65 per hour or a fixed price based on the specific job.
- Keep in mind that contractors who charge by the hour may be cheaper for minor repairs but can cost significantly more if the plumber encounters unexpected problems.
- If you can’t find good plumbers online, ask friends, family, and neighbors for personal recommendations.
Additionally, check your homeowner’s insurance policy; some cover the cost of essential plumbing repairs.
Keep in mind that plumbers using special equipment can confirm that there is actually a leak and can isolate any problems to a specific area.
Remember that most slab leaks can only be repaired by breaking the concrete, so look for general contractors, pipe repair specialists, and have most of the suggested features.
Now that you know how to detect water leaks under slabs, invest in an excellent plumber to save money on their repair.