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Coastal climate and exposure detailing · Lesson 1 of 4

Coastal climate and exposure detailing: principles and terminology

Where coastal salt comes from and how far it matters, why the side facing the sea and the sheltered undersides behave as they do, the Texas windstorm inspection frame, and the safety boundary for roof and edge inspection.

You will be able to: Explain how salt spray reaches and corrodes metal near a coast, which building surfaces suffer most, how the Texas windstorm program frames coastal work, and who decides what on a coastal project.

11 min · 12 slides · 7 questions

All lessons in this module
Slide 1 of 12

Where the salt comes from

Breaking waves turn salt water into spray, and the wind carries that spray inland.

FEMA's TB 8 says the amount of salt spray is greatest near breaking waves and declines rapidly in the first 300 to 3,000 feet landward of the shoreline.

TB 8 adds that onshore winds carry both salt and moisture inland, so corrosion rates are higher along shorelines with mostly onshore winds.

Salt spray thins with distance from the shorelineSide view: sea on the left, breaking waves, an onshore wind arrow, a building with its ocean-facing wall marked, and dots that thin out inland. Brackets below mark 300 ft, 300 to 3,000 ft, and 5 to 10 miles landward of the shoreline.Salt spray thins with distanceABCD300 ft300 to3,000 ft5 to 10 miDistances landward of the shoreline,from FEMA TB 8. Dots thin out inland.Not to scale.

Side view: sea on the left with breaking waves, an onshore wind arrow, a building with its ocean-facing wall marked in amber, and teal dots that are dense near the shore and thin out inland. Brackets below mark 300 ft, 300 to 3,000 ft and 5 to 10 miles landward of the shoreline.

A
Breaking waves turn salt water into spray
B
Onshore wind carries salt and moisture inland
C
Ocean-facing side of a building, which TB 8 reports corrodes much faster
D
Salt spray: greatest near breaking waves, declining rapidly in the first 300 to 3,000 feet
Distances from FEMA TB 8, drawn to show the idea, not to scale.

Sources

Videos for this lesson

What this video shows: TDI explains TWIA, and that a newly built home or home repairs need an inspection and a certificate of compliance (called a WPI-8) to get a TWIA policy.

Video: Windstorm insurance in Texas by Texas Department of Insurance (TDI), on YouTube. Chosen from the video's published description.

Glossary

Salt spray
Salt water turned into airborne spray by breaking waves and carried inland by the wind. FEMA TB 8 says it is greatest near breaking waves and declines rapidly in the first 300 to 3,000 feet landward.
Exposure class (FEMA TB 8)
TB 8's term for the kind of location a metal connector or fastener sits in, such as partially sheltered exterior or open exposed exterior. It is different from the wind-load term "Exposure Category".
Designated catastrophe area
The area where the Texas Department of Insurance windstorm program applies: 14 coastal counties and parts of Harris County east of Highway 146.
WPI-8 and WPI-8-E
TDI certificates of compliance: a WPI-8 is issued for ongoing construction and a WPI-8-E for completed construction. A WPI-8-E inspection can be done by a Texas-licensed professional engineer.
Sheltered exposure
A surface rain does not reach, such as an underside or soffit. TB 8 reports that such areas do not get rain's occasional rinsing, accumulate more salt and can corrode faster than open ones.