Roof Runoff & Gutter Calculator
See how much water your roof sheds in a DFW storm and whether your downspouts keep up.
Estimates use typical industry ranges and published methods. They are not a quote. An on-site moisture inspection sets the actual scope.
How storm water gets inside
- Hail damage that cracks shingles and knocks off granules, letting water reach the decking.
- Wind damage that lifts or tears off shingles and ridge caps.
- Failed flashing around chimneys, vents, skylights and wall intersections.
- Wind-driven rain forced through soffit vents, windows and door thresholds.
- Overflowing gutters that back water up under the roof edge or dump it against the foundation.
After a storm: protect the inside
- Get a tarp on any opening as soon as it's safe. Most policies require you to prevent further damage.
- Check the attic with a flashlight for wet insulation, dripping decking and stained rafters.
- Put buckets under drips, and relieve any bulging ceiling with a small hole at its low point.
- Photograph the roof damage (from the ground or a safe vantage), the attic, and every interior stain.
- Get interior drying started. Wet attic insulation loses its value and holds moisture against the ceiling drywall.
Drainage around the house matters too
A 2,000 sq ft roof sheds over 1,200 gallons in a one-inch rain. During a severe storm, that water arrives in a rush, and undersized gutters or short downspouts dump it right at the slab. On DFW's expansive clay, repeated soaking and drying next to the foundation can contribute to foundation movement, and water pooling at the slab edge can get inside. The calculator above checks whether your gutters can keep up.
Insurance for storm and roof leaks
Rain that enters through storm damage (hail or wind creating an opening) is typically covered by homeowners insurance, subject to your deductible. Many Texas policies have a separate wind/hail deductible, often a percentage of the dwelling coverage, which can be much larger than the standard deductible. Leaks from an old, worn-out roof are usually treated as maintenance. Rising floodwater needs a flood policy.