PROTECT YOUR BUILDINGS

Windows

Windows can be broken at even fairly low wind speed by flying debris. Hurricane shutters or pieces of ply over the outside of the window frame will be good enough for the low wind speeds of maybe a direct hit by a category 1 hurricane.

However, as wind speeds increase the loosly help pieces of ply will fly off, and hurricane shutters may be good to mid-category 2.

For the best protection the widows or shutters when closed should be 2 " inside the frame. Window frames can be increased in depth by simply adding timber around the frame.

Hurricane board

 

The 2 " inset gives room for the placement of a piece of 1/2" plywood for small windows, and 5/8" plywood for larger windows, inside the window frame.

An alternative is to use sliding bolts to secure the plywood. See PDF from "A Short Lesson in Building Effective Shutters" presented at the Impact of Climatic Variations on the Caribbean region Hurricanes Meeting, July 20-21, 1999.

 

 Hurricane board
An alternative means to securerly fix hurricane boards is the use of bolts. We found these were more expensive and difficult to make than using a wood stip to hold the plywood. The bolt fixed plywood is slightly more easy to secure and much easier to take down than wood strip fixed plywood.

Roofs

Roofs are mainly lifted by wind through the same effect that lifts planes with thier wings. So roofs that are fairly flat produce the greatest lift. So one way to reduce wind damage on roofs is to make them about 30-35%.

Four-sloped hip roofs perform better under wind forces than the gable roofs with two slopes. Gable roofs with two slopes will be better than single slope roofs. Research and testing demonstrate that a 30-degree roof slope will have the best result

Roof overhangs are subject to wind uplift forces which could trigger a roof failure. In the design of the hurricane-resistant home, the length of these overhangs should be limited to about 20 inches.

The effect of wind on roofs can be reduced and their structral strength can be increased by:

1. Simply breaking the wind flow across the roof (and strenghening roof structure) by placing 3 x 2 inch timber along nail lines at least every 2.5 feet.

2. Tying the timber into the buidling wall structure.

3. Increasing the strength of the roof timber and joins. The joists can be the most important thing.

4. Nailing or screwing the roof iron on more securely.

5. Have overhangs at the roof edge less than 20 inches accross or make a side roof seperate from main roof.