Most of the time, it’s not immediately apparent whether or not a slab leak is present. That’s when we turn to other tests and observations designed to rule out other issues. In order to do that, various water supply shut-off valves need to be accessible and in proper working order: -Main Water Shut-Off Valve: Every single home in Texas has a main water shut-off valve, though you may not know where it is. If you didn’t know you had one, it could be in a state of disrepair, especially if your home was built before 2012. To avoid making any potential leaks worse, have this valve inspected before you use it. -Irrigation Double Check Valve: Look for a rectangular box with a green lid near the street or your main water meter. Inside, you’ll find the irrigation double check valve. Having this valve in good condition is important so that we can isolate the irrigation system from your main water supply, ensuring the leak isn’t on the irrigation side. -Water Heater Shut-Off Valve: We also need to isolate the water heater when we perform slab leak testing. A properly functioning valve on your water heater will help us completely shut off the water that goes to your water heater. -Toilet Supply Shut-Off Valves: Also known as an angle stop, this valve is critical for times when toilets are leaking, overflowing, or constantly running. A poor quality or builder-grade angle stop could be behind a leak situation. We always recommend (though we don’t require) that our customers upgrade any plastic angle stops to metal, corrosion-resistant, quarter-turn type valves. -Hose Spigot or Bib: The valve outside your home where you connect your hose needs to be leak- and drip-free while we’re testing for slab leaks. We’ll use one of your hose spigots to attach our pressure gauges to the water supply system, so we need at least one to be in good working order.