Second Homes and Vacant Houses: How to Catch a Slab Leak While You're Away

A slab leak in a home you live in is caught eventually, by a warm floor, a sound or a high bill. A slab leak in a home that sits empty can run for weeks before anyone notices. Lake houses, Hill Country weekend places, homes between tenants, homes on the market and houses left empty during a long trip all face the same risk. This guide explains how to protect a vacant or part-time home from a long-running slab leak, with options from free to high-tech.

Why vacant homes are at higher risk

When nobody is home, nobody notices the early signs. There is no one to feel a warm spot, hear a hiss or see damp carpet. Water bills may arrive after the damage is done, especially if they are mailed to another address or paid automatically. Meanwhile, a hidden leak keeps soaking the soil under the slab and wicking moisture into flooring and walls. In humid parts of Texas, mold can follow.

Vacant homes also face freeze risk in winter, and power outages that leave pipes unprotected.

Option 1: Shut off the water when you leave

The simplest, cheapest protection is to close the main shut-off valve when the house will be empty. With the main closed, a leak downstream cannot run for more than whatever was already in the pipes.

Before you rely on this:

• Find the main shut-off and make sure it closes fully and opens again. Old valves can stick or leak.
• Decide about the water heater. Many manufacturers recommend turning a tank heater to vacation or pilot mode when water is off, rather than leaving it heating with no supply. Follow your heater's manual.
• Check irrigation. If your irrigation is fed from the house line after the shut-off, it will be off too; if it has a separate connection, plan accordingly.
• Consider fire sprinklers, if your home has them; do not shut off water that feeds a fire system.

Option 2: Drain the lines in winter

For extended winter absences, especially in North Texas, the Panhandle and the Hill Country, consider shutting off the main and draining the lines by opening the lowest faucets and hose bibs. Some owners have a plumber winterize the home. Check your insurance policy, since some policies limit freeze coverage for vacant homes unless specific precautions are taken.

Option 3: Use your utility's online portal

Many Texas utilities and MUDs offer online portals with daily or hourly usage, and some send alerts for continuous usage or spikes. If the house is empty, usage should be near zero. Any steady usage means something is running. Set up alerts if available and check the portal regularly while you are away.

Option 4: Smart leak sensors

Battery-powered leak sensors placed near the water heater, under sinks, behind toilets and in the laundry area alert your phone when they detect water. They will not detect a slab leak directly, since that water goes into the soil, but they catch many other leaks that can do serious damage in an empty house, and some can detect temperature drops that signal freeze risk.

Option 5: Smart shut-off valves

Smart water shut-off valves installed on the main line monitor flow and can close automatically if they detect a leak pattern, such as continuous flow for too long. Many also let you close the valve from your phone. Some can detect small, continuous flows typical of a hidden slab leak. They require professional installation and power or a network connection. For second homes and frequently vacant properties, they offer strong protection.

Option 6: A neighbor or property manager routine

A trusted neighbor or property manager can:

• Read the meter on a schedule and compare it with the last reading.
• Walk through the house looking for damp spots or smells.
• Check that the heat or AC is running.
• Make sure the main shut-off is still closed if that was the plan.

A simple written checklist makes this easy.

When you return

Each time you return to a part-time home, do a quick check:

1. Open the main slowly and listen for unusual sounds.
2. Do a meter test: with everything off, read the meter, wait an hour, and read it again. If it moves, investigate.
3. Walk the floors for warm or damp spots.
4. Check under sinks, around toilets and at the water heater.
5. Smell for mustiness.

Our water meter leak test guide explains how to read the meter.

If you find a leak from afar

If an alert, a neighbor or your usage data suggests a leak while you are away:

1. Have the water shut off at the main as soon as possible.
2. Arrange for someone to check for visible water damage and start drying if needed.
3. Schedule slab leak detection. It can often be arranged with someone present to provide access. Our slab leak detection overview explains what happens.
4. Notify your insurer if there is damage.
5. Call your water utility about a possible leak adjustment.

Homes for sale and between tenants

Vacant homes on the market are a special case: realtors and buyers walk through, but no one lives there. Ask your agent to check the meter periodically, or install a smart shut-off. Between tenants, do a meter test during turnover and consider shutting off the main until the next move-in, if practical.

A sample checklist for a house sitter or neighbor

Give whoever checks on the house a short written list. On each visit: note the date and time; read the water meter and write down the number; compare it with the last reading; walk through every room looking for damp carpet, stains or puddles; check under the kitchen and bathroom sinks and around the water heater; sniff for musty smells; confirm the thermostat is set where you left it; and text you a photo of the meter. If the meter number changed while the house was empty, or anything looks wet, they should close the main shut-off and call you. A list like this takes ten minutes per visit and catches problems while they are still small.

Insurance considerations for vacant homes

Many homeowners policies include vacancy provisions that limit coverage if a home is unoccupied for an extended period, such as 30 or 60 consecutive days, particularly for water damage and freeze damage. Policies for second homes or vacation homes may have their own terms. Ask your agent how your policy treats vacancy, what precautions it requires, and whether a vacancy endorsement is available.

Choosing the right level of protection

Not every vacant home needs every tool. A good approach is to match protection to risk. For a weekend house you visit every few weeks, closing the main when you leave and checking the meter when you arrive may be enough. For a home that sits empty for months, especially in winter, adding a smart shut-off valve and a neighbor's monthly check makes sense. For a rental between tenants, a turnover meter test and a closed main until move-in is simple and effective. For a high-value property or one in a humid area where mold is a concern, combining sensors, a smart valve and usage alerts gives the best coverage. Whatever you choose, write it down so everyone who visits the house follows the same routine.

Owners who travel or keep second homes, from Sun City in Georgetown to river cabins in New Braunfels and lake houses near Conroe, benefit most from these habits.

The bottom line

A slab leak in a vacant or part-time home can run unnoticed for weeks. Shutting off the main when you leave is the simplest protection. Add usage alerts, leak sensors or a smart shut-off valve for more peace of mind, and set up a routine for a neighbor or manager. Every time you return, do a meter test and walk the floors. When you need a leak located, find your city to book a licensed Texas plumber, or see our slab leak FAQs.