Preventing mold in Dallas homes: a seasonal guide

April through September is when most Dallas mold problems start. The combination of storms, heat, and humidity creates ideal conditions.

After every major storm: • Walk the perimeter of your house and check for standing water near the foundation. Water should drain away from the house, not toward it. • Check the attic for leaks. Look for daylight through the roof, water stains on sheathing, and wet insulation. Catch a roof leak in April and you prevent a mold problem in June. • Clear gutters and downspouts. A clogged gutter overflows directly against the fascia and soffit, which are perfect mold food. • Inspect windows and doors for water intrusion. Look for wet sills, stained frames, or condensation between panes.

Humidity control (ongoing May-September): • Keep indoor humidity between 45% and 55%. Buy a hygrometer for $10-15 at any hardware store and check it weekly. If you're consistently above 60%, your HVAC may be oversized (cools the air without running long enough to dehumidify) or your ductwork may be leaking. • Run bathroom exhaust fans during showers and for 30 minutes after. If you don't have an exhaust fan, crack a window. Bathroom humidity is the most common cause of residential mold in Dallas. • Run the kitchen exhaust fan while cooking, especially when boiling water or using the dishwasher. • Make sure your dryer vents outside. A dryer vented into a garage or attic pushes warm, moist air into spaces where mold thrives.

HVAC maintenance: • Check and clean the condensate drain line monthly during summer. A clogged condensate line backs up into the drip pan, overflows, and wets the area around your air handler. This is the source of a surprising number of attic and closet mold problems. • Change your air filter monthly during heavy-use months. A dirty filter restricts airflow, which causes the evaporator coil to freeze and then thaw, dripping water in places it shouldn't. • Have your system serviced annually. A technician can check refrigerant levels, clean the coil, and inspect ductwork for condensation issues.

Dallas winters are mild compared to most of the country, but they bring their own mold risks.

Fall checklist (October-November): • Clean gutters before leaf drop fills them. A gutter clogged with leaves in November causes roof-edge water damage during winter rains. • Inspect roof flashing, especially around chimneys, vent pipes, and dormers. Dallas roofs take a beating from summer storms and hail. Damaged flashing lets winter rain into your attic. • Check crawl spaces for moisture. Fall is a good time to inspect because ground moisture is usually at its lowest. If you see standing water, condensation on surfaces, or musty smell, address it before winter rains start. • Test your sump pump if you have one. Pour a bucket of water into the pit and make sure the pump activates and drains properly.

Winter maintenance (December-February): • Insulate exposed pipes, especially in the attic, garage, and exterior walls. Dallas gets a hard freeze event roughly once per winter. A burst pipe during a freeze is the number-one cause of the major mold events we respond to. The 2021 winter storm caused more mold remediation work in Dallas than anything we'd seen in a decade. • Keep some heat running in unused rooms. Closing off rooms to save energy drops the temperature, which raises the relative humidity in that space. A cold, humid room grows mold. • Check attic ventilation. Proper ridge and soffit ventilation prevents warm, moist air from collecting in the attic and condensing on cold surfaces. If you see frost on the underside of your roof sheathing on a cold morning, your ventilation is inadequate.

These aren't seasonal. Do them all the time:

• •Fix leaks within 24 hours. This is the single most effective mold prevention measure. A dripping faucet, a running toilet, a slow pipe leak under a cabinet, these feed mold. Fix them immediately.
• •Check under sinks monthly. Open every cabinet under a sink in your house, look for drips, feel for dampness, check for musty smell. Kitchen and bathroom supply line failures are quiet and go unnoticed for weeks.
• •Keep furniture off exterior walls. Leave 2-3 inches of space between furniture and exterior walls for air circulation. Warm, stagnant air against a cold wall creates condensation.
• •Don't store cardboard boxes on concrete floors. Cardboard absorbs moisture from concrete, especially in garages and storage rooms. Use plastic bins or put boxes on shelving.
• •Monitor your water bill. A sudden unexplained increase in water usage often means a hidden leak. Many water companies will flag unusual usage for you.
• •Clean AC condensate drain lines quarterly with a cup of white vinegar. This prevents algae buildup that clogs the line.

Mold prevention is mostly about paying attention to moisture. Most of the mold problems we remediate in Dallas could have been prevented with a leak repair that would have cost a fraction of the remediation bill.

If you're not sure whether your home has a moisture problem, we offer free visual inspections across the Dallas metro. Call (214) 432-6986.