Is this a roof leak, an air-handler leak or a plumbing leak?
Timing is the strongest clue. A roof leak follows rain, often wind-driven rain; an air-handler leak follows long hot afternoons when the system has been running for hours; a plumbing leak ignores the weather and comes with a meter that keeps moving. Where the stain sits and when it grows usually names the source before anyone opens the attic.
Keep a short log for a week or two: the date, the weather, whether the air conditioner ran for long stretches, and whether the stain moved. A stain that grows only after rain points up the slope. One that grows on dry, hot days, particularly near the attic hatch or under the air handler, points at a clogged condensate line, which is an air-conditioning contractor's repair. A stain under a bathroom or a water heater that grows whatever the weather is a plumber's question.
The meter settles the plumbing side fast. With every fixture and appliance closed, a dial that keeps turning means water is escaping somewhere in the supply, and no amount of roof work will touch it. If the dial is still, a supply line is not the source, which leaves the roof, the air handler and condensation.
From the attic hatch, a flashlight shows the rest: dark staining on the underside of the deck around a vent or chimney, damp insulation on one slope only, or a wet trail running down a rafter. Look from the opening rather than stepping in. Insulation hides the joists, and ceiling board will not carry a person.
Why does a roof leak show up so far from the hole?
Because water follows framing, not a straight line. It runs down the underside of the deck, along a rafter or across a duct, soaks the insulation and surfaces wherever the ceiling board gives way, which can be a room away. A stain marks where water arrived, not where it came in.
The route is set by gravity and by whatever is in the way. Water that gets past the shingles and the underlayment soaks the deck, slides down toward the eave, drops onto a joist or a ceiling-mounted fan housing, and spreads across the top of the drywall. Insulation absorbs the first of it and hands it on slowly, so the ceiling can stay unmarked for days while the attic is already wet.
In a two-story house the water does not stop at the top-floor ceiling. It can run down inside an exterior wall, along the top plate and out at a baseboard on the floor below, or soak the ceiling of the room under an upstairs bathroom. So the technician reads the walls and the room beneath as well as the stained board, and the wet area that gets measured usually turns out wider than the stain.
Big houses stretch the route. In Preston Hollow, Highland Park and University Park, where big roofs sit over finished upper floors, water entering one slope can cross an upstairs room and a hallway before it shows in a lower ceiling. The same logic applies to a modest bungalow, only with fewer places for the water to hide.
How much water can a roof put into a house, and when is a tarp worth it?
One inch of rain over one square foot of roof is about 0.62 gallons, so a 2,500-square-foot roof surface sheds about 1,550 gallons under a single inch. A leak admits a small share of that, but small shares add up, which is why a tarp is worth it whenever more rain is coming than a roofer can beat.
Take that 2,500-square-foot figure as an example, not a measurement of your house; a pitched roof has more surface than the footprint under it. At the 9.19 inches DFW Airport recorded in 24 hours on August 22, 2022, a roof standing under that gauge would have received roughly 5.7 gallons on every square foot. A roof is built to shed that water, but a fraction that finds a cracked shingle still soaks insulation and ceiling board quickly.
That arithmetic is why the second rain is the one to prevent. A small, localized leak with dry weather ahead can wait for a roofer's appointment, provided you have photographs, a bucket and an eye on the forecast. A larger opening, a storm in the forecast or a ceiling that has already sagged justifies a cover now, and the cost range for a tarp is in the table above.
Do not tarp it yourself. A wet slope is slick, and a fall from a one-story eave can still injure. Ask the roofer for a written scope of the permanent repair, and let the crew photograph the roof damage before covering it so the roofer and your insurer see the same record.
When do roof leaks start in Dallas, month by month?
They follow the weather calendar. Winter wear shows up as leaks from March, hail and tornado season peaks in April and May, flash floods follow in June, a second severe-weather season arrives in October, and a rare hard freeze can leave ice on roofs in January. September is the month for checking the roof.
A roof that took hail in April and leaks in a long rain in August is not unusual here, because bruised shingles often hold up through showers. The sequence below is a guide to when the questions tend to arise, not a forecast, and the National Weather Service Fort Worth office posts the actual warnings for Dallas County.
Use September as a working month. It sits between the two severe-weather seasons, and a check of the roof, the gutters and your shut-off valves then costs far less than the same check done after a leak has started.
- January and February: rare hard freezes can leave ice on roofs, and thaw water finds seams that were tight in dry weather
- March: severe-storm season begins, and wear from winter shows up as leaks
- April and May: peak hail and tornado season, with roof and ceiling leaks and flash flooding on saturated ground
- June to August: flash floods and heat; roofs that were bruised in spring can start leaking in the next hard rain
- September: the month for roof, gutter and shut-off checks
- October: a second severe-weather season arrives
Who handles what, and does insurance pay for a roof leak?
A roofer repairs the roof, the crew covers the opening and dries the inside, and your insurer decides coverage under your policy. Hail and wind claims may carry a separate deductible, shown on the declarations page. Whether a leak counts as sudden storm damage or as long-term wear is a question for your agent, not for the crew.
Texas Department of Insurance guidance draws the main line between sudden and accidental damage and slow seepage, and an insurer may weigh a storm-related leak differently from one that built up over years under an aging roof. Photographs with dates, the roofer's findings and the crew's moisture readings are what you hand over, and the Texas water damage insurance guide lists the usual exclusions.
A house in Winnetka Heights stands in a Dallas historic district whose exterior changes pass through the city's historic-preservation review, so ask the city whether roof work counts before the roofer orders materials. In every case, repair after drying may need a city permit, and Texas has no state general-contractor license, so the answer depends on which city you are in.
Roofs and mold meet in the attic. The EPA calls drying within 24 to 48 hours a guideline, not a deadline, and notes that mold may have grown even when materials were dried inside that time, so a clean reading and a clear smell both count. If growth appears, TDLR licenses mold assessors and remediators in Texas, and one license holder may not do both jobs on the same project, so testing and removal cannot lawfully be bought as one package at 25 contiguous square feet or more.