Tracer gas can be particularly useful when trying to find a water leak under a concrete floor or slab. The molecular size of the gas is far smaller than the water, the escaping gas will easily permeate through the concrete and emerge at the surface where it can be detected using the 'sniffer' air sampling equipment.
Step 1: Keep an eye out for signs of a concrete slab leak
Signs that you might have a leak under the concrete slab of your home include: A sudden decrease in water pressure. Water collecting in areas it shouldn't. Areas of carpet that stay damp.
Slab leaks are a common problem, but not one that many homeowners are aware of. Plenty of water lines, pipes, and drains run through the slab, and as your home ages, you could face damage from fractures, cracks, and splits that cause a leak.
Since water lines are laid down under the concrete slab, there can be minor damage such as small nicks when the concrete is poured. Although these occurrences may not cause immediate leaks, they can weaken the pipes and grow into a leak-causing crack later.
Water Leaks Under Concrete Can Cause Serious Foundation Damage. Given that concrete foundations are porous, water will fill any pores it can find, eventually causing the foundation to crack and shift, and leaving homes unsettled.
For the most precise leak detection, plumbers use video pipe inspection equipment. These are small cameras mounted on long flexible fiber optic cables. Plumbers can insert these in faucets and other plumbing outlets to detect leaks.
Specialist acoustic equipment is the most effective way of detecting water leaks underground. When water that's under pressure escapes from a leaking pipe it creates tiny vibrations. Using a highly sensitive microphone that's placed on the ground, these vibrations are amplified as sound.
The only way to stop water from coming up through your foundation slab is by installing a drain tile system, vapor barrier, and sump pump. Installing a vapor barrier will counter moisture seepage – A vapor barrier is a thin (10 to 20-mil thick) sheet of polyethylene that's placed along your foundation walls.
When it rains, water is absorbed into the ground until the earth is too saturated to soak up any more water. At this point, the water will begin to rise to the surface, causing hydrostatic pressure to build up against your foundation and basement floors, which leads directly to water seepage into your home.
Due to everyday wear and tear situation, concrete becomes prone to cracks and holes. Water can penetrate these spaces which could result in further leakage. In some less complicated cases, you can perform minor roof repairs. For this, you will need mortar or roof cement, roof primer, and an elastomeric sealant.
One method of fixing a leak under a slab is to run a new water line alongside the existing one to bypass the leaky section. Another method is to insert a new lining into the existing pipe to seal and strengthen the pipe.
Here are some slab leak symptoms to look out for: A raised “dome,” water stains, or warm spots on the floor. Foundation heaving caused by shifting or swelling soil. An increase in water or heating bills, as well as low water pressure.
In some cases, there may even be noticeable pooling of water from a slab leak inside or outside of your home. If you see water pooling around the outside of your home on an otherwise dry day, this should be investigated as a possible slab leak.
Locate your water meter and check the leak indicator to see if it is moving. Depending on the brand of your meter, the leak indicator could be a small triangular shaped dial or a small silver wheel that rotates when water is flowing through the meter. If the dial is moving, chances are, you have a leak.
If the water meter test indicates a leak inside your home, check the cabinets under the kitchen, laundry, and bathroom sinks to make sure they're dry. You'll also want to look for puddles around the bases of tubs, toilets, and showers and beneath the water heater, dishwasher, and clothes washer.
Cracked or warped flooring or spongy spots in the floor indicate the presence of moisture and a possible leak. Examine the walls and ceilings in rooms located directly beneath bathrooms as well. Stains on the ceiling or walls, and bubbling or peeling paint or wallpaper, indicate a leak somewhere in those pipes.
However, concrete is porous. 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.