Put Cloudbreak on your portfolio.

Leave your email and we’ll reach out within one business day.

Prefer to talk? Call 940-391-3558.

Hail vs your roof

Count how often hail near a building has reached the published damage size for its roof.

Published damage size

1 to 2 in.

TPO, PVC or other plastic single-ply

Weather history and published rules of thumb, not a damage assessment. Only an inspection can show a roof's condition.

What a hail damage threshold is

A hail damage threshold is the smallest hail that might cause functional damage to a type of roofing.1 It is a rule of thumb, not proof that hail of that size did or did not damage a roof. This tool counts how often hail has reached that size near a building.1

How to read the results

  • Radar at this address: the largest hail radar estimated over the point, day by day, since October 2020.2
  • Ground reports within 5 miles: days with hail reported near the building, since 2010.3
  • Two counts for one roof: where the published size is a range, the tool counts days at each end of it.
  • Never added together: radar and ground reports measure different things and can disagree about the same storm.

Reports come from trained spotters and the public, so they cluster near towns and roads. A low count does not show that a roof was untouched.

Where the numbers come from

Haag's published hail damage thresholds1
RoofingThreshold
Lightweight asphalt shingles1 in.
Heavyweight asphalt shingles1.25 in.
Clay tile1.5 in.
Concrete tile1.75 in.
Built-up roofing, smooth2 in.
Modified bitumen1.5 to 2 in.
EPDM, smooth2 in.
Other plastic single-ply, smooth1 to 2 in.
Membranes ballasted with gravel2.5 in.
Galvanized steel panels2.5 in.

Haag sets these from lab impact tests with ice balls at free-fall speeds, checked against field inspections.1

What moves a roof's real threshold

  • What is under the membrane: a firm cover board can make a roof far more resistant than one over a soft substrate.4
  • Age and condition: a threshold is a rule of thumb for a roofing type, and it does not know how this roof has aged.1
  • The storm itself: size is one factor among several in whether hail causes damage.1

Questions

Does this tool say my roof is damaged?
No. It counts weather history against a published rule of thumb. Only an inspection can show a roof's condition.
What does a count of zero mean?
That nothing in this data reached that size. It does not show the building was untouched: hail can fall where no one reports it, and a threshold is only a rule of thumb.1
Why are radar and ground reports shown separately?
They measure different things. Radar estimates hail over a point from the sky, while reports record what people saw nearby. They can disagree about the same storm, so the tool never adds them.
Why does a TPO roof show two counts?
Haag gives plastic single-ply membranes a range of 1 to 2 inches rather than one size, so the tool counts days at each end of the range.1

Terms used here

Sources

The address goes to Cloudbreak's app, which finds its map point with Geocodio, a geocoding service. The app keeps the matched address and point for 30 days, filed under a one-way hash of what was typed, so a repeat lookup skips the geocode. The address is never sent to analytics. The published sizes are from the sources below.

  1. 1. Haag Engineering: Hail Damage Thresholds: What do they really mean?
  2. 2. NOAA NWS Warning Decision Training Division: Maximum Estimated Size of Hail (MESH)
  3. 3. NOAA Storm Prediction Center: Storm Prediction Center Severe Weather Summaries
  4. 4. IIBEC Interface: Impact Resistance of Roof Coverings

All free tools