Hurricane Shutters - Design 1
Shutters for:
Wood-Frame Buildings
One of the best ways to protect a home from damage in wind storms is to install shutters over all large windows and glass doors. Shutters protect doors and windows from wind-borne objects. They also prevent damage caused by sudden pressure changes when a window or door is broken.
This design guide from APA - The Engineered Wood Association describes how to construct structural panel shutters for attachment to wood-frame buildings. It also includes basic design considerations for all structural panel shutters. Additional designs from APA provide details for shutters that can be attached to masonry or concrete block buildings.
Design Considerations
General
Most building codes don't include provisions for storm shutters. Those few that do have design requirements only if shutters are provided. According to these codes, shutters should deflect less than the shutter span (in inches) divided by 30 (for instance, a 40-inch span should not bend more than 40/30 = 1.33 inches when the wind blows). They also should bend less than 2 inches maximum and should remain at least one inch away from the window when under full wind force.
The easiest designs are those that simply cover the opening with a structural panel. In wood-frame construction, panels can be nailed over the openings when a hurricane approaches. Buildings made with concrete blocks require advance preparation.
In some cases, stiffeners may be necessary to limit deflection of the shutter against the glass. Stiffeners function best if the 2 x 4s are on the outside of the shutter and oriented with the narrow edge against the shutter.
Note: The shutter design shown herein will provide significant protection from hurricane-force winds. This publication contains recommendations to serve as a guide only. It does not include all possible shutter, anchor and fastening systems, and the installer must adjust all dimensions to compensate for particular installations and hardware used. These shutter designs by no means represent all possible workable designs and can always be upgraded to provide even greater margins of safety and protection. All shutter designs herein are intended to be temporary, and mounted and removed from outside the building. All designs are based on wind pressure capacities only.
While the design wind pressures used are based on ASCE 7-95, the building owner/installer must still carefully evaluate each system and then, if necessary, make any modifications consistent with good design and building practices. Steps to Constructing Shutters
This APA hurricane shutter design is based on pressures associated with a design wind speed of 120 mph. Building codes are currently being reviewed for possible changes. Before constructing shutters, therefore, it is important to check with your local building department for an update on current code requirements.
|
|
|||
|---|---|---|---|
| APA Panel Span Rating |
Approximate Weight (lb./ft.2) |
Maximum Shutter Span |
Approximate Deflection (in.) at 120 mph Design Wind Speed at 15-ft. Height |
| 32/16 | 1.5 | 30 | 0.5 |
| 40/20 | 2 | 36 | 0.5 |
| 48/24 | 2.4 | 48 | 0.9 |
| 48 oc | 3.6 | 72 | 1.5 |
| TABLE 2 Estimated Deflection at 120 mph Design Wind Speed at 15-ft. Height for Shutters with 2 x 4s at 16 inches o.c. |
||||||||
|---|---|---|---|---|---|---|---|---|
| APA Panel Span Rating |
Approx. Weight (lb./ft.2) |
Shutter Span (in.) | ||||||
| 24 | 36 | 48 | 60 | 72 | 84 | 96 | ||
| 32/16 | 2.5 | 0.2 | 0.2 | 0.3 | 0.4 | 0.5 | 0.8 | - |
| 40/20 | 2.9 | 0.1 | 0.1 | 0.2 | 0.2 | 0.4 | 0.7 | 1.1 |
| 48/24 | 2.9 | - | - | 0.1 | 0.2 | 0.3 | 0.6 | 1.0 |
| 48 oc | 4.6 | - | - | 0.1 | 0.1 | 0.3 | 0.5 | 0.9 |
Steps to Constructing Shutters
- Review Tables 1 and 2 in the Design Considerations section to determine if stiffeners are needed.
- Cut APA wood structural panels with adequate edge overlap to receive nails.
- Use a long brad or finishing nail to locate the framing behind the wood siding. The nails used to attach the shims and the shutters must hit the framing to be fully effective.
-
FIGURE 1 Shutter Stiffner Attachment - If Required
FIGURE 2 Shutter Attachment
View from Outside
- Nail shims to the framing with 12d nails. Use 16d nails for shims over 3/4 inch thick. Space the shim nails 6 inches o.c. (Figures 3a and 3b)
- Attach the shutters with double-headed nails for ease of later removal. (Figures 3a and 3b) Use 12d nails for shutters up to 3/4 inch thick and 16d nails for shutters over 3/4 inch thick. For spans up to 5 feet, space the nails 6 inches o.c. at each end of the shutter panel. For spans over 5 feet, space nails 4 inches o.c. at each end of the shutter panel. Nailing the panel on all four sides, instead of just the two ends, will further limit deflection and maximize strength.
APA offers a series of Hurricane Shutter Designs. They include:
Design 1: Shutters for Wood-Frame Buildings
Design 2: Shutters for Masonry Block Structures, Barrel Bolt Latch Supports
Design 3: Shutters for Masonry Block Structures, Steel or Aluminum Angle and Screw Supports
Design 4: Shutters for Masonry Block Structures, Shutters Attached to Outside Wall with Permanently Mounted Brackets
Design 5: Shutters for Masonry Block Structures, For Openings Wider than 8 Feet
Each design is available from APA - The Engineered Wood Association for $1. Designs may also be ordered as a complete set for $5. To order, contact APA - The Engineered Wood Association, P.O. Box 11700, Tacoma, Washington 98411-0700. Phone: (253) 565-6600. FAX: (253) 565-7265.
© 1998 APA -- The Engineered Wood Association
