Water Damage and Mold in Nevada Homes

Why Nevada Homes Get Wet Differently

Nevada is one of the driest states, yet water damage here is common. The difference is in where the water comes from. In Nevada, the water usually comes from inside the house or from a sudden storm.

• Hard water in the Las Vegas valley scales up and wears out water heaters, valves and supply lines faster than normal.
• Slab foundations are standard in most valley homes, so a leaking pipe can hide under the floor.
• Rooftop equipment such as evaporative coolers and AC units sits right above the ceilings it can leak into.
• The summer monsoon brings short, intense storms and flash floods to southern Nevada.
• Northern Nevada, including Reno, Carson City and the Tahoe side, gets hard freezes and snow that burst pipes and load roofs.

The dry air works both for you and against you. Wet surfaces in an open room dry fast, which helps after a small spill. But water trapped inside a wall, under a slab or under flooring can stay wet for weeks while everything around it looks fine.

Hard Water Wears Out Plumbing Fast

Most Las Vegas valley water comes from Lake Mead, and it is very hard, well above the level the USGS calls very hard. The minerals do not hurt your health, but they leave scale inside pipes, valves and appliances. That scale shortens part life and makes leaks more likely.

The white crust on fixtures is mineral scale, not mold. A vinegar soak removes it from showerheads and aerators.

Angle stops that seize are a real Las Vegas problem. If you cannot close the valve under your sink when a supply line bursts, you are running to the main shutoff instead. Exercise these valves twice a year so they work when you need them.

A water softener or scale reducing system can cut buildup if it is set up and maintained correctly.

Slab Leaks

In many valley homes, water lines run through or under the concrete slab. When a pipe wears through, the leak happens under your floor where you cannot see it. Hot water lines tend to fail more often because heat and expansion stress them.

Signs of a slab leak include these.

• A warm spot on a tile or wood floor, often in a line
• The sound of running water when every fixture is off
• A water bill that jumps with no change in use
• Damp carpet or tack strip, or flooring that lifts, with no leak above it
• New cracks in tile or a musty odor at floor level

To check, turn off every fixture and appliance that uses water, then watch the meter. If the leak indicator keeps moving, water is going somewhere. Then close the valve to the water heater and check again. If the meter stops, the leak is likely on the hot side.

A leak detection specialist can pinpoint a slab leak with acoustic and thermal tools. Repair options include opening the slab for a spot repair or rerouting the line through walls and the attic. Many homeowners policies cover the cost to access the pipe and the resulting damage but not the pipe itself, so read your policy and call your agent early.

Swamp Coolers, Rooftop AC and Drain Lines

Evaporative coolers, often called swamp coolers, are still common on older valley homes and on garages. Most sit on the roof and are fed by a small water line. When the float valve sticks, the pan rusts through or the bleed line clogs, water can pour into the duct and come through the ceiling below.

• Spring startup. Check the pan for rust, replace pads, test the float and look at the supply line for cracks before the first hot day.
• During the season. Look at the ceiling around the cooler vent for stains. Open a window or two while it runs, because a cooler needs exhaust air to work and adds moisture to the house.
• Fall shutdown. Turn off and drain the water line, empty the pan, close the damper and cover the unit. This matters even more in northern Nevada, where a filled line can freeze.

Central AC brings its own water. The indoor coil drips condensate into a pan and down a drain line. In many valley homes the air handler sits in the attic, so a clogged line spills into the ceiling. A secondary drain pan with a float switch that shuts the system off is your best protection. Pour a cup of white vinegar into the drain access fitting once or twice a summer, and check the pan when you change filters.

Water in the secondary pan means the main drain is failing, so call an HVAC tech.

Dry Air Hides Wet Walls

Low outdoor humidity is one of the best things about drying out after a spill here. The trap is assuming that dry looking means dry.

Water that runs into a wall cavity, under a cabinet, under tile or into a slab has almost no air to dry into. It can stay wet for weeks, feeding mold on the back of the drywall and the bottom plate while the room reads bone dry. Common spots are behind a dishwasher, under the kitchen sink base, behind toilets, at the base of showers, and under the ceiling below a leaking cooler or AC pan.

• Use a moisture meter on drywall and baseboards near any leak, and compare it with a dry wall in the same room.
• Pay attention to a musty smell in a closed cabinet or closet. In this climate, a musty odor is a strong clue.
• Check stucco walls near sprinkler heads and drip lines for dark stains or white deposits at the base.

If readings stay high after a few days of fans, the cavity likely needs to be opened to dry. That is a much smaller job at day three than at week six.

Monsoon Season and Flash Floods

Southern Nevada’s summer monsoon, roughly July to September, brings short, violent thunderstorms. A storm can drop a large share of a year’s rain on one neighborhood in under an hour while the next neighborhood stays dry. Desert soil and pavement shed that water fast, and it gathers in washes, channels and streets.

Never enter moving water on foot or in a car. Washes and dips that are dry most of the year can carry fast water, mud and debris within minutes. Water only a foot deep can float many cars.

For your home, the risks are roof leaks and water flowing in at ground level.

• Before July, check flat roof drains and scuppers and clear debris. Look at tile roofs for slipped or cracked tiles. The underlayment beneath tile ages in the sun and is often the real leak.
• Keep yard drains and the side yard path clear so water can leave the lot.
• If your home sits near a wash or low spot, keep sandbags or water barriers ready for door thresholds.

Standard homeowners policies do not cover flood water from outside. Flood insurance is a separate policy, and a new policy through the National Flood Insurance Program usually has a 30 day waiting period, so buy it before the season, not during a storm warning.

After a flash flood, treat the water as contaminated. Mud and floodwater carry sewage and debris, and wet drywall and carpet it touched usually must be removed.

Freezing Pipes in Northern Nevada

Reno, Sparks, Carson City and the rest of northern Nevada see real winter. Nights well below freezing are common, and the Tahoe side gets heavy snow.

• Hose bibs. Disconnect garden hoses before the first hard freeze. A hose left on traps water in the spigot. Use foam covers, or have a plumber install frost free hose bibs.
• Crawlspaces and garages. Insulate pipes that run through them and keep crawlspace vents closed in deep cold if your home allows it.
• Outside walls. On the coldest nights, open cabinet doors under sinks on outside walls and let a faucet drip.
• Thermostat. Keep the heat at 55 degrees Fahrenheit or higher, including when you travel.
• Coolers and irrigation. Drain swamp cooler lines and blow out or drain sprinkler lines in fall.

In mountain areas, snow can form ice dams at the roof edge that push meltwater under shingles. Good attic insulation and ventilation help prevent them.

The Truckee River has flooded parts of Reno and Sparks in very wet winters, including 1997 and early 2017. If you are near the river, check your flood zone and consider flood insurance.

Hiring Help in Nevada

In Nevada, most construction and repair work must be done by a contractor licensed through the Nevada State Contractors Board. You can look up any license by name or number on the board’s website. Check that the license is active, that the classification fits the work, and whether there are complaints or disciplinary actions.

• Nevada licenses carry a monetary limit. Make sure the contractor’s limit covers the size of your job.
• Be wary of anyone who asks for a large payment up front, shows up uninvited after a storm, or pushes you to sign today.
• The board runs a Residential Recovery Fund that can help owners of single family homes who are harmed by a licensed contractor. It does not protect you if you hire an unlicensed one.

Nevada does not have a separate state mold license like New York does. For mold work, ask about training and industry certification, ask whether the company will also do the rebuild, and consider an independent assessment for larger jobs so the person who tests is not the person who profits from the cleanup.

If you rent, tell your landlord about leaks and mold in writing and keep a copy. Nevada law requires landlords to keep rentals habitable and sets notice steps you should follow. Use the directory to find a specialist near you when a job is past DIY.

Step by Step

1. Exercise Every Angle Stop

   Turn each valve under sinks and behind toilets off and back on twice a year. Replace any that are stiff, crusted or drip at the stem.

2. Flush the Water Heater

   Turn off power or gas, attach a hose to the drain valve and run a few gallons into a bucket or drain until the water runs clear. Have the anode rod checked every few years.

3. Watch the Meter for a Slab Leak

   Turn off all water use and watch the meter’s leak indicator. If it moves, close the water heater inlet and check again to see if the leak is on the hot side.

4. Start Up or Shut Down the Cooler

   In spring, check the pan, pads, float and supply line. In fall, drain the line and pan, close the damper and cover the unit.

5. Clear the AC Drain

   Pour a cup of white vinegar into the condensate access fitting once or twice a summer. Check that the secondary pan is dry and the float switch works.

6. Prep for Monsoon

   Before July, clear roof drains, check tiles and flashing, and open the path for water to leave your lot. Decide whether you need flood insurance well before storms arrive.

Mistakes That Make It Worse

• Trusting the dry surface after a leak. Wall cavities and slabs can stay wet for weeks in a room that looks fine.
• Letting angle stops seize. In a burst, a valve that will not close sends you running to the main.
• Leaving a swamp cooler line full over winter. It can freeze, split and leak into the ceiling on the first warm day.

Where You Live Matters