Your Weather Shield

Watch as protective layers wrap around your building. Each layer works together to keep the Florida Keys weather outside where it belongs.

The building envelope is your first and last line of defense against 175 mph winds.

PROTECTION LEVEL
CURRENT LAYER
Structure
Wind
Rain
UV

The 5 Layers of Protection

Each layer plays a critical role in keeping your home safe

1

Structural Frame

The skeleton of your building. In the Keys, this means concrete block, reinforced poured concrete, or engineered wood frame with hurricane straps at every connection.

Wind Borne Debris Region 175 MPH Design
2

Sheathing & Substrate

Plywood or OSB panels that cover the frame. They must be nailed in a specific pattern - closer at edges, every 6 inches at panel perimeters in high-wind zones.

8d Ring-Shank Nails 4" Edge Spacing
3

Weather Barrier

House wrap, building paper, or fluid-applied membrane. This layer stops water but lets vapor escape. In salt air, fluid-applied barriers last longer than stapled wraps.

Secondary Water Barrier Self-Sealing
4

Exterior Cladding

Stucco, siding, or panels that you see from outside. Must be rated for 175 mph. Fiber cement outperforms vinyl in the Keys because it resists salt degradation.

Impact Resistant Corrosion Resistant
5

Openings Protection

Windows, doors, and garage doors are the weak points. Monroe County requires impact-rated glazing or approved shutters on all openings.

Large Missile Level D Miami-Dade NOA
R

Roof System

Your roof is under the most stress. It needs proper decking attachment, secondary water barrier, and rated covering - plus sealed edges and proper flashing.

FBC High-Velocity Zone Sealed Deck

What Happens When the Envelope Fails

Window Breach

A window breaks. Wind rushes in and pressurizes the interior, pushing up on the roof from inside.

Internal pressure: +35 psf

Door Failure

An entry door or garage door fails. Larger opening means faster pressurization and higher internal forces.

Internal pressure: +45 psf

Combined Failure

Multiple openings fail. The building becomes a balloon with holes. Roof uplift forces can double.

Internal pressure: +60 psf

Envelope Inspection Checklist

Check these before hurricane season

Windows sealed - no gaps in caulking
Door weather stripping intact
Garage door reinforcement installed
Shutters tested and operational
Roof shingles/tiles secure
Soffit vents rated for wind
Stucco cracks repaired
Flashing sealed at penetrations

0 of 8 items checked

Common Questions

What is a building envelope?

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The building envelope is everything that separates inside from outside: roof, walls, windows, doors, and foundation. In the Florida Keys, it must resist 175 mph winds, flying debris, heavy rain, and salt spray. Think of it as your home's protective skin.

Why do buildings fail at the envelope during hurricanes?

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Most hurricane failures start with an envelope breach. Once wind enters through a broken window or door, internal pressure builds up and can blow off the roof. This is why Florida Building Code requires impact-rated openings in hurricane zones.

What are the requirements for windows in Monroe County?

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Windows in Monroe County must be either impact-rated (Large Missile Level D) or protected by approved shutters. Impact glass must withstand a 9-pound 2x4 shot at 50 feet per second, plus cyclic pressure testing. All windows need Miami-Dade NOA approval.

How do I maintain my building envelope in the Keys?

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Inspect caulking and sealants annually - salt air degrades them faster. Check weather stripping on doors and windows. Look for cracks in stucco or siding. Clean weep holes in window frames. Test garage doors and shutters before hurricane season.
ENVELOPE FACTS
5
Protective Layers
175
MPH Wind Rating
2X
Uplift If Breached