Plywood hurricane shutters can be far more effective when they are installed inside window frames instead of nailed into walls, hurricane experts said.
The Correct Way
By cutting the plywood to fit snugly inside window frames, the wind is far less able to get underneath and tear it away. The wood should be attached to the inside of the window sill using barrel bolts (pictured at left). This style performed well even in 1992's devastating Hurricane Andrew. It should work on any window frame at least two inches deep.
The Good Alternative
For concrete block walls, use lead-sleeve anchors.
Use 2 1/2-inch long bolts and screws.
Use CDX plywood at least 5/8 inch thick.
Place plywood over window, allowing a 4-inch overlap on each side.
Space bolts or screws 12 to 18 inches apart.
The Wrong Way
Some people install homemade wood shutters by nailing plywood to the outside of window frames. This might survive weaker hurricanes, but strong winds can seep under and pull the plywood off, removing any protection.
Use exterior plywood and 3- or 4-inch heavy-duty barrel bolts.
Set plywood in 2 inches deep.
Have bolts in the center of each side of the frame to keep it secure. For larger windows, use one bolt every two feet.
The holes in the window frame should be just large enough for the bolt.
Measure every side of the window frame for a snug fit.
Use 2x4 lumber or full-length piano hinges to connect pieces of plywood for extremely large windows, such as sliding glass doors.
Waterproof with varnish or paint.