Hurricane Shutter Designs Refer to Form No. T460 for design considerations for Florida

Hurricane Shutter Designs Refer to Form No. T460 for design considerations for Florida One of the best ways to protect a home from damage in windstorms is to install shutters over all large windows and glass doors. Shutters protect windows from windborne objects. They also prevent structural damage caused by sudden pressure changes when a window is broken. Figure 1 High Wind Zones of the Contiguous United States VASD mph 85 90 100 110 120 130 140 150 Notes: 1. Values are nominal design 3-second gust wind speeds, Vasd, in miles per hour at 33 ft above ground for Exposure C category. 2. Linear interpolation between contours is permitted. 3. Islands and coastal areas outside the last contour shall use the last wind speed contour of the coastal area. 4. Mountainous terrain, gorges, ocean promontories, and special wind regions shall be examined for unusual wind conditions. Source: Figure R301.2(4)A, 2012 International Residential Code

2 The following designs are presented as two basic alternatives: The first is to present the code minimum opening protection when such shutters are required. The requirements of the 2012 International Residential Code (IRC) and the 2012 International Building Code (IBC) are presented. They permit the use of minimum 7/16 Performance Category Rated Sheathing as opening protection against the impact of windborne debris. Check with local building departments for verification or clarification of requirements. The second approach provides some design details for stronger and stiffer shutters than provided for by the codeminimum requirements. It should be noted that these designs were developed prior to the adoption of specific standards for shutter designs by any U.S. codes. The supports detailed for these shutters meet code requirements when mounted according to the specifications in Table R301.2.1.2. The mounting brackets for the masonry block structures have been tested for design wind loads but have not been impact or cyclic tested because they were developed as design guides before these standards were developed. 1. Code-Minimum Shutter Design IRC Section R301.2.1.2 Protection of openings. Exterior glazing in buildings located in windborne debris regions shall be protected from windborne debris. Glazed openings protected from windborne debris shall meet the requirements of the Large Missile Test of ASTM E1996 and astm E1886 referenced therein. The applicable wind zones for establishing missile types in ASTM E1996 are shown on Figure R301.2(4)C. Garage door glazed opening protection for windborne debris shall meet the requirements of an approved impact-resistant standard... Exception: Wood structural panels with a minimum thickness of 7/16 inch and a maximum span of 8 feet shall be permitted for opening protection in one- and two-story buildings. Panels shall be precut and attached to the framing surrounding the opening containing the product with the glazed opening. Panels shall be predrilled as required for the anchorage method and shall be secured with the attachment hardware provided. Attachments shall be designed to resist the components and cladding loads determined in accordance with either Table R301.2(2) or ASCE 7, with the permanent corrosion-resistant attachment hardware provided and anchors permanently installed on the building. Attachment in accordance with Table R301.2.1.2 is permitted for buildings with a mean roof height of 33 feet or less where located in Wind Zones 1 and 2 in accordance with Figure R301.2(4)C. TABLE R301.2.1.2 WindBORNE debris PROTECtion fastening SCHeduLE for Wood structural panels (a)(b)(c)(d) Fastener Type No. 8 wood screw based anchor with 2-inch embedment length No. 10 wood screw based anchor with 2-inch embedment length 1/4-inch lag screw based anchor with 2-inch embedment length Fastener Spacing (inches) (a)(b) Panel Span 4 ft 4 ft < Panel Span 6 ft 6 ft < Panel Span 8 ft 16 10 8 16 12 9 16 16 16 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound = 4.448 N, 1 mile per hour = 0.447 m/s. (a) This table is based on 130 mph (V asd ) wind speeds and a 33-foot mean roof height. (b) Fasteners shall be installed at opposing ends of the wood structural panel. Fasteners shall be located a minimum of 1 inch from the edge of the panel. (c) Anchors shall penetrate through the exterior wall covering with an embedment length of 2 inches minimum into the building frame. Fasteners shall be located a minimum of 2-1/2 inches from the edge of concrete block or concrete. (d) Where panels are attached to masonry or masonry/stucco, they shall be attached using vibration-resistant anchors having a minimum ultimate withdrawal capacity of 1500 pounds.

3 Hurricane Shutter Designs Figure 2 Wind Borne Debris Regions of the United States Wind Zone 1 (1 mile from the Coastal Mean High Water Line) Wind Zone 2 Wind Zone 3 Notes: 1. Wind Zone 3 applies in Wind Zone 2 areas that are within a mile of the Coastal Mean High Water Line. 2. Wind Zone 1 applies in Hawaii Special Wind Regions. 3. See Section 1609.1.2.2 of 2012 International Building Code for definitions of wind zones. Source: Figure R301.2(4)C, 2012 International Residential Code Section R202 defines Windborne Debris Regions as areas within hurricane-prone regions as designated in accordance with Figure R301.2(4)C. This figure is reproduced in Figure 2 of this publication. This figure is based on the following criteria: 1) within one mile of the coastal mean high water line where the basic wind speed is 110 mph or greater; or 2) where the basic wind speed is equal to or greater than 120 mph; or 3) Hawaii. For Florida provisions, see Hurricane Shutters: Design Considerations for Florida, Form T460. Form No. T450G 2013 APA The Engineered Wood Association www.apawood.org

4 Alternatively, Section 1609.1.2 of the 2012 International Building Code: In windborne debris regions, glazing in buildings shall be impact-resistant or protected with an impact-resistant covering meeting the requirements of an approved impact-resisting standard or astm E1996 and astm E1886 referenced therein as follows: 1. Glazed openings located within 30 feet of grade shall meet the requirements of the Large Missile Test of astm E1996. 2. Glazed openings located more than 30 feet above grade shall meet the provisions of the Small Missile Test of ASTM E1996. ExCEPtions: 1. Wood structural panels with a minimum thickness of 7/16 inch and maximum panel span of 8 feet shall be permitted for opening protection in one- and two-story buildings classified as Group R-3 or R-4 occupancy. Panels shall be precut so that they shall be attached to the framing surrounding the opening containing the product with the glazed opening. Panels shall be predrilled as required for the anchorage method and shall be secured with the attachment hardware provided. Attachments shall be designed to resist the components and cladding loads determined in accordance with the provisions of ASCE 7, with corrosion-resistant attachment hardware provided and anchors permanently installed on the building. Attachment in accordance with Table 1609.1.2 with corrosion-resistant attachment hardware provided and anchors permanently installed on the building is permitted for buildings with a mean roof height of 45 feet or less where V asd determined in accordance with Section 1609.3.1 does not exceed 140 mph. (Figure 3 is provided for determining the V asd wind speed measured at 33 feet above ground for Risk Category II Buildings (Group R-3 or R-4 occupancy). This figure is based on the wind contours for Risk Category II Buildings from 2012 IBC Figure 1609A. 2. Glazing in Risk Category I buildings as defined in Section 1604.5, including greenhouses that are occupied for growing plants on a production or research basis, without public access shall be permitted to be unprotected. TABLE 1609.2.1.2 WindBORNE debris PROTECtion fastening SCHeduLE for Wood structural panels (a)(b)(c)(d) Fastener Type No. 8 wood screw based anchor with 2-inch embedment length No. 10 wood screw based anchor with 2-inch embedment length 1/4-inch lag screw based anchor with 2-inch embedment length Fastener Spacing (inches) (a)(b) Panel Span 4 ft 4 ft < Panel Span 6 ft 6 ft < Panel Span 8 ft 16 10 8 16 12 9 16 16 16 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound = 4.448 N, 1 mile per hour = 0.447 m/s. (a) This table is based on 140 mph, V ULT (110 mph, V asd ) wind speeds and a 45-foot mean roof height. (b) Fasteners shall be installed at opposing ends of the wood structural panel. Fasteners shall be located a minimum of 1 inch from the edge of the panel. (c) Anchors shall penetrate through the exterior wall covering with an embedment length of 2 inches minimum into the building frame. Fasteners shall be located a minimum of 2-1/2 inches from the edge of concrete block or concrete. (d) Where panels are attached to masonry or masonry/stucco, they shall be attached using vibration-resistant anchors having a minimum ultimate withdrawal capacity of 1,500 pounds.

5 Hurricane Shutter Designs Figure 3 Vasd Contours for determining suitability of Wood Structural Panel Glazing Protection Devices for Risk Category II Structures 85 90 95 100 110 120 125 132 140 150 Notes: 1. Values are nominal design 3-second gust Vasd wind speeds in miles per hour at 33 ft above ground for Exposure C category. 2. Linear interpolation between contours is permitted. 3. Islands and coastal areas outside the last contour shall use the last wind speed contour of the coastal area. 4. Mountainous terrain, gorges, ocean promontories, and special wind regions shall be examined for unusual wind conditions. 5. Wind speeds correspond to approximately a 7% probability of exceedance in 50 years (Annual Exceedance Probability = 0.00143, MRI = 700 years). Source: Derived from 2012 IBC Figure 1609A and Equation 16-33. 3. Glazing in Risk Category II, III or IV buildings located over 60 feet above the ground and over 30 feet above aggregate surface roofs located within 1,500 feet of the building shall be permitted to be unprotected. Section 202 defines a Windborne Debris Region as: Areas within hurricane-prone regions located: 1. Within 1 mile of the coastal mean high water line where the ultimate design wind speed, Vult, is 130 mph (100 mph VASD ) or greater; or 2. In areas where the ultimate design wind speed, Vult, is 140 mph (110 mph VASD ) or greater; or Hawaii. Based on Equation 16-33, Vasd = 0.6 x Vult maps for Risk Category II and Category III and IV are found in the 2012 IBC in Figures 1609A and B, respectively, and not provided herein. Form No. T450G 2013 APA The Engineered Wood Association www.apawood.org

6 Section 202 defines Hurricane-Prone Regions as: 1. The U.S. Atlantic Ocean and Gulf of Mexico coast where the ultimate design wind speed, V ult, for Risk Category buildings is greater than 115 mph (90 mph V asd ); and 2. Hawaii, Puerto Rico, Guam, Virgin Islands and American Somoa. 2. Considerations for Stronger, Stiffer Designs The following design pages describe how to construct stronger, stiffer shutters for attachment to wood and masonry walls. The masonry attachments were designed prior to the adoption of specific test standards for shutter designs by U.S. codes. The shutters have been tested to resist the design wind loads and impacts, but the attachments to masonry have not been impact or cyclic-load tested. The masonry attachment details are therefore supplied as guides in developing individual designs. The easiest designs are those that simply cover the opening with a wood structural panel. In wood-frame construction, panels can be nailed over the openings when a hurricane approaches. Buildings made with concrete blocks, however, require advance preparation. In some cases, stiffeners may be necessary to limit deflection of the shutter with respect to the glass. Stiffeners function best if they are on the outside of the shutter and oriented with the narrow edge against the shutter. Tables 1 and 2 and Figures 4 and 5 on the following pages apply to most of the designs, and are referenced accordingly.

7 TABLE 1 Maximum Span without Stiffeners Strength axis perpendicular to fastener rows (see figure 2) APA Panel Span Rating Approximate Weight (psf) Maximum Shutter Span (in.) Approximate Deflection at V asd 150 mph Design Wind Speed at 45-ft Height, Exp. C, Wet Panels (in.) 32/16 1.5 22 0.22 40/20 2.1 30 0.38 48/24 2.4 34 0.35 48 oc 3.6 50 0.58 Table 2 Weights and Deflections of shutters with Stiffeners (a) (See Figure 3) Maximum Span Approximate Weight (Stiffener Bending) APA Panel Span Rating Minimum Panel Specification 32/16, 15/32 Perf. Cat. 5-ply plywood or OSB 40/20, 19/32 Perf. Cat. 4-ply plywood or OSB 48/24, 23/32 Perf. Cat. Plywood or OSB 48 o.c., 1-1/8 Perf. Cat. Plywood or OSB With 2x4 Stiffeners (psf) With 2x6 Stiffeners (psf) With 2x4 Stiffeners (b) at 16" o.c. (in.) With 2x6 Stiffeners (b) at 16" o.c. (in.) Total Deflection (Stiffener Plus Panel) 66" Span with 2x4 Stiffeners (in.) 96" Span with 2x6 Stiffeners (in.) 2.4 2.9 66 96 0.87 0.97 2.8 3.3 66 96 0.75 0.86 3.2 3.7 66 96 0.66 0.79 4.3 4.8 66 96 0.49 0.67 (a) Panels with 2x4 S-P-F (South) No. 2 stiffeners spaced 16 inches o.c., Exposure C, 3-second gust, Wall Zone 5, mean roof height = 45 ft, V ASD 150 mph, 2012 IBC. (b) Maximum span governed by stiffener bending strength, wet stresses, duration of load factor = 1.6.

8 Figure 4 Shutter installation example showing orientation of panel strength axis Orientation is based on Figure A1 Panel strength axis (perpendicular to the fastener rows) Panel shutter Shutter span Rows of fasteners Figure 5 Shutter Stiffener Attachment If Required APA structural panel No. 2 2x4 or No. 2 2x6 Cut if desired Panel strength axis 3/16" x 3" lag screws with fender washers Min. 16d box nails (0.135" x 3-1/2") @ 6" o.c.

9 Hurricane shutter Designs index

10 Design a Shutters for Wood-Frame Buildings This design from APA describes how to construct structural panel shutters for attachment to wood-frame buildings. Steps to Constructing Shutters 1. Review Tables 1 and 2 to determine if stiffeners are needed. Attach stiffeners, if needed, as shown in Figures 5 and A1. 2. Cut APA wood structural panels with adequate edge overlap to receive nails. Orient long panel axis (strength axis) of the panel as shown in Figures 5 and A1. 3. Use a long brad, finishing or casing nails 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. 4. Nail shims to the framing with 12d nails (0.135- x 3-1/4-inch). Use 16d nails (0.135- x 3-1/2-inch) for shims over 3/4 inch thick. For spans up to 5 feet, space the nails 6 (4) inches o.c. at each shim. For spans over 5 feet, space nails 4 (3) inches o.c. at each shim. Stagger nails as shown in Figure A2. Refer to Figures A2 and A3. Shim attachment schedules are based on a mean roof height of 33 feet. Corresponding schedules for a mean roof height of 45 feet are shown in parenthesis, e.g., 12 (8). 5. Attach the shutters with double-headed nails as shown in Figures A2 and A3 for ease of later removal. Use 16d (0.135- x 3-1/2-inch). For nail spacing at each end of the shutter panel, see Tables A1 and A2. Stagger nails spaced 3 inches on center. Nailing the panel on all four sides instead of just the two ends will further limit deflection and maximize strength. Table A1 Minimum Nail Spacing along Each End of the shutter Panel (Span Ratings 32/16, 40/20, 48/24 plywood or OSB) Shutter Mean Roof Height (ft) Height (ft) 33 45 5 6" o.c. 4" o.c. 8 3" o.c. 3" o.c. Table A2 Minimum Nail Spacing along Each End of the shutter Panel (Span Rating 48 oc, 1-1/8" plywood or OSB) Shutter Mean Roof Height (ft) Height (ft) 33 45 5 4" o.c. 4" o.c. 8 3" o.c. 3" o.c. 6. Any permanently installed hardware, shims or fastening devices must be installed using standard/acceptable methods of waterproofing. All abandoned holes must be sealed. 7. After fabrication, each shutter should be marked for orientation and location to speed installation. 8. If shims are left in place, use galvanized nails and finish like siding or exterior trim.

11 Figure A1 Shutter Attachment View from Outside Cut if desired APA structural panel No. 2 2x4s or No. 2 2x6s (if needed) Panel strength axis Span 16d (0.135" x 3-1/2") double-headed nails in accordance with Tables A1 and A2 Figure A2 Shutter Attachment Top Siding Shim Maintain a minimum panel edge distance of 1/2" 1" 16d (0.135" x 3-1/2") double-headed nails per Table A1 or A2 16d (0.135" x 3-1/2") nails holding shims per Step 4 Header Finish wall Flashing and caulk Shutter Interior casing Glass

12 Figure A3 Shutter Attachment Bottom Glass Finish sill Shutter Sill 16d (0.135" x 3-1/2") double-headed nails per Table A1 or A2 Maintain a minimum panel edge distance of 1/2" 1" Shim Siding Interior casing Caulk (prior to installing shim) Finish wall 16d (0.135" x 3-1/2") nails holding shims per Step 4

13 Design B Shutters for Masonry Block Structures Barrel-Bolt Latch supports This design from APA describes how to construct structural panel shutters for attachment to masonry block buildings using barrel-bolt latch supports. The unique features of this design are the barrel bolt latches that support the shutter at either end. Once made, the shutters can be mounted or removed without any additional hardware or tools. The barrel-bolt latches should be mounted to the panel with bolts rather than the screws that usually come with them. Use a washer under the nuts and heads of the bolts. Place the nut-end of the bolts to the outside (latch side) of the shutter to allow for final adjustment of the latches. Steps to Constructing Shutters 1. Use Tables 1 and 2 to determine if stiffeners are needed. Attach stiffeners, if needed, as shown in Figure 5. 2. Cut the panel 1/8 inch less than the window opening. The long-panel axis (strength axis) must be oriented perpendicular to the supported ends (sides of the shutter with the barrel bolts), regardless of which shutter dimension is longer. 3. Make two templates that will help in mounting the latches and drilling the barrel-bolt latch holes in the concrete blocks one for each side of the window. The maximum distance between the top of the shutter panel and the first barrel bolt, and the maximum distance between barrel bolts shall be in accordance with Table B1 and should miss the mortar joints between the blocks by 1-1/2 inches or more. See Figure B1. 4. Mount 4-inch barrel bolts. The nuts go on the latch side (outside) of the shutter. Make the nuts only finger tight because the latches will be adjusted in the final fitting. 5. Drill latch-bolt holes in blocks. See Figure B2. Table B1 Barrel Bolt Attachment schedule Mean Roof Height (ft) Shutter Width 33 45 (ft) Distance to First Barrel Bolt (in.) 5 6 5 8 4 3 Barrel Bolt Spacing (in.) 5 12 10 8 8 6 6. Mount the shutter in the window frame, and insert the barrelbolt latches into the holes in the concrete blocks. Tighten bolts holding barrel bolts in place. 7. The barrel-bolt holes in the concrete blocks may be filled with a removable plug when not in use as shown in Figure B3. 8. Any permanently installed hardware, shims or fastening devices must be installed using standard/acceptable methods of waterproofing. All abandoned holes must be sealed. 9. After fabrication, each shutter should be marked for orientation and location to speed installation. 10. To prevent the bottom 2x4 anchor holes in the concrete block from becoming clogged with dirt between shutter uses, insert 1/2-inch No. 14 pan- or flat-head screws into the anchor holes. Remove these screws prior to reattaching the 2x4s.

14 Figure B1 Latch Bolt placement Details Note: Be sure to mark the location and orientation of each shutter after fabrication TOP NORTH SIDE CENTER Distance to first barrel bolt per Table B1 Barrel bolt spacing per Table B1 Panel strength axis 4" barrel bolt Front view 1-1/2" Hole for latch bolt 4'' Barrel bolt 1-1/2" Wall end view Masonry joints Outside face of wall APA structural panel 3/8" cut washers No. 8 machine screws Section view of barrel bolt Figure B2 LATCH-Bolt HOLE in Side of Window Opening Figure B3 Temporary plug FOR LATCH-Bolt HOLE Block 1" Stucco Holes for latch bolts not greater than 16" o.c. Hole for latch bolt Cork Plug for latch-bolt hole Screw handle 1-1/2" minimum Block Stucco

15 Design C Shutters for Masonry Block Structures Steel or Aluminum Angle and Screw supports This design from APA describes how to construct structural panel shutters for attachment to masonry block buildings, using steel or aluminum angle and screw supports. The design is less costly to build than shutters with permanent hardware for attachment and removal. Anchorage to Masonry Block The plastic anchors* referenced in this plan have sufficient lateral and withdrawal capacity to handle the expected forces and are recommended because they are rated as being vibration resistant a characteristic that may be of some value under buffeting wind loads. (Standard lead anchors are not usually rated as vibration resistant.) Keep masonry anchors at least 1-1/2 inches from the block edges, joints and corners to minimize the danger of cracking the concrete blocks. Steps to Constructing Shutters 1. Use Tables 1 and 2 to determine if stiffeners are needed. Attach stiffeners, if needed, as shown in Figure 5. 2. In the dimension from support to support, cut the panel 3/8 inch less than the measurement of the window opening (side to side in Figure C1). In the dimension from unsupported edge to unsupported edge, cut the panel 1/8 inch less than the measurement of the opening. The long-panel axis (strength axis) must be oriented perpendicular to the supported sides (side to side in Figure C1), regardless of which shutter dimension is longer. 3. Cut 1-1/2 x 1-1/2 x 1/8-inch steel or aluminum angles to the same length as the width of the shutter ends to be supported. 4. Drill 1/4-inch diameter holes per Table C1 in one side of the angle. These holes are for bolts that hold the angle to the panel and may be centered between the corner and the edge of the angle. 5. Drill 3/16-inch diameter holes per Table C2 in the remaining leg of the angle, offset 1 inch from the panel bolt holes. Make the centerline of the holes 1/4 inch from edge of the angle. These holes are to receive No. 10 screws that will go through the holes into masonry anchors in the concrete blocks. Refer to Figure C2. Table C1 Hole Locations in Angle for Attachment of shutter Panel Mean Roof Height (ft) Shutter Width 33 45 (ft) Machine Bolt Spacing (in.) 5 12 12 8 12 12 Distance to First Machine Bolt (in.) 5 6 6 8 6 6 Table C2 Hole Locations in Angle for Attachment to Wall Mean Roof Height (ft) Shutter Width 33 45 (ft) Concrete Anchor Spacing (in.) 5 8 8 8 6 4 Distance to First Concrete Anchor (in.) 5 4 4 8 3 2 *Lateral ultimate value 350 lbs or greater in 4,000 psi concrete, with screws specified (1-1/2 inches with stucco).

16 6. Drill holes in blocks for the plastic anchors. Refer to Figure C3. 7. Mount the shutter, with angles mounted, to the window frame using No. 10 x 1-1/2" screws with washers. See Figure C1. 8. Any permanently installed hardware, shims or fastening devices must be installed using standard/acceptable methods of waterproofing. All abandoned holes must be sealed. 9. After fabrication, each shutter should be marked for orientation and location to speed installation. 10. To prevent the bottom 2x4 anchor holes in the concrete block from becoming clogged with dirt between shutter uses, insert 1/2-inch No. 14 pan- or flat-head screws into the anchor holes. Remove these screws prior to reattaching the 2x4s.

17 Figure C1 Shutter Attachment Detail Note: Be sure to mark the location and orientation of each shutter after fabrication TOP NORTH SIDE CENTER Panel strength axis Block wall Outside view of wall 1/4" Dia. hole Block wall 1-1/2" x 1-1/2" x 1/8" Aluminum or steel angle 1/4" x 1" screw-in anchor (1-1/2" screw-in anchor for stucco) per Table C2 Front or outside 3/32" Dia. hole APA structural panel No. 8 machine screw with 1/4" x 1-1/4" fender washers per Table C1 1-1/2" minimum No. 10 wood or sheet metal screw 3/16" Dia. hole Block wall top view Figure C2 Angle-to-ShuTTER ATTACHMEnt Detail 1-1/2" x 1-1/2" x 1/8" Aluminum or steel angle APA structural panel Figure C3 SCREW-In AnCHOR HOLE in Side OF WinDOW Opening 1" Stucco 1/4" Dia. hole per Table C1 3/32" Dia. hole 3/16" Dia. hole per Table C2 Hole for 1'' screw-in anchor (1-1/2" screw-in anchor for stucco) per Table C2 Block 1-1/2" minimum

18 Design D Shutters for Masonry Block Structures Shutters Attached to Outside Wall with Permanently Mounted Brackets This design from APA describes how to construct structural panel shutters for attachment to masonry block buildings, using permanently mounted brackets on the outside wall. Two layers of APA Exterior plywood are attached to the outside of the concrete block wall with No. 10 flat-head screws in masonry anchors. Once the brackets are installed, no tools are required to install or remove the shutters unless stiffeners are required. It has the advantage of moving the shutter almost 2 inches farther away from the glass than shutters mounted to the interior of the window frame and is therefore less likely to require stiffeners. Fasteners Screws or bolts that will be permanently exposed to the weather should be made of stainless steel. Anchorage to Masonry Block The plastic anchors* referenced in this plan have sufficient lateral and withdrawal capacity to handle the expected forces and are recommended because they are rated as being vibration resistant a characteristic that may be of some value under buffeting wind loads. (Standard lead anchors are not usually rated as vibration resistant.) Keep masonry anchors at least 1-1/2 inches from the block edges, joints and corners to minimize the danger of cracking the concrete blocks. Steps to Constructing Shutters 1. Use Tables 1 and 2 to determine if stiffeners are needed. Attach stiffeners, if needed, as shown in Figure 5. 2. Cut APA Exterior plywood for the shutter support/spacer and for the trim that holds shutter against the supports (see Figure D1). Make the thickness of the inner spacer slightly greater than that of the shutter to allow the shutters to slide without binding. (The inner trim spacer of plywood is left out of one side of the window framing to allow for the insertion of the shutters.) Orient the plywood face grain of the trim as indicated in the diagram. (Plywood with four or more plies may be oriented either direction.) Lap the corners to allow the outer trim to be attached to the inner spacer at the corners. Refer to Figure D1. 3. Drill 1/2-inch diameter vertical drain holes in bottom inner spacer to allow rain water to escape out the bottom. Table D1 Trim-to-ConCRETE Anchor SPACing Mean Roof Height (ft) Shutter Height 33 45 (ft) Concrete Anchor Spacing (in.) 5 12 12 8 9 6 Distance to First Concrete Anchor (in.) 5 6 6 8 4 3 4. Cut the shutter to be 1/4 inch less than the distance from the bottom of the bottom slot to the top of the top slot, and about 2 inches wider than the window opening width (assuming that the panels are supported top and bottom). Orient the long-panel axis (strength axis) as shown in Figure D1. Slide the shutter into place. 5. Drill hole halfway down the trim and diagonally downward (at about 30 degrees from the surface) in the trim board covering the shutter-entrance opening. The hole should be about 1/8 inch outside the edge of the installed shutter. This hole will receive a 12d box (0.128 x 3-1/4-inch) nail to prevent the shutter panel or panels from getting blown back out the entrance slot. *Withdrawal ultimate value 490 lbs or greater in 4,000 psi concrete, with screws specified (1-1/2 inches with stucco).

19 Figure D1 Shutter frame and Attachment Structural Panel Option Lap trim at corners Shutter location marked on shutter Shutter slot (3 sides) Strength axis Drain hole Panel strength axis TOP NORTH SIDE CENTER Face trim Not required for reinforced shutters Hole for shutter stop Detail of locking device APA structural panel shutter 1/4" x 1" Screw-in anchor (1/4" x 1-1/2" for stucco) in accordance with Table D1 No. 10 screw Inner spacer 3" 4" 1-1/2" Minimum 1/2" Plywood face trim Block Side view Thickness of shutter plus 1/8" Note: Using sawn lumber instead of plywood for the outer layer of trim may result in the failure of the trim when suction loads are applied to the shutter. 6. Any permanently installed hardware, shims or fastening devices must be installed using standard/acceptable methods of waterproofing. All abandoned holes must be sealed. 7. After fabrication, each shutter should be marked for orientation and location to speed installation. 8. To prevent the bottom 2x4 anchor holes in the concrete block from becoming clogged with dirt between shutter uses, insert 1/2-inch No. 14 pan- or flat-head screws into the anchor holes. Remove these screws prior to reattaching the 2x4s. Design Alternative As an alternative to Design D, the wood trim can be replaced with 1 x 1 x 1-inch (outside measurements) x 1/8-inch aluminum channels (channel outside dimensions may be changed to better accommodate panels thicker than 5/8 inch i.e., 1-1/8-inch-thick shutters will require a channel slot opening of about 1-1/4 inches) mounted approximately the same way as the wood trim. See Figure D2. Make holes at both ends to hold a latching device to prevent shutters from being blown out.

20 Figure D2 Shutter frame and Attachment aluminum Channel Option Stucco Block 1/4" x 1" screw-in anchor (1/4" x 1-1/2" for stucco) in accordance with Table D1 1-1/2" Minimum 1/2" Aluminum channel 1" x 1" x 1" x 1/8" No. 10 screw

21 Design E Shutters for Masonry Block Structures For Openings Wider Than 8 Feet This design from APA describes how to construct structural panel shutters for attachment to masonry block buildings, where glass windows and doors are wider than 8 feet. The shutters run from top to bottom and are attached to a temporary 2x4 lumber strip at the top and bottom of the opening. Anchorage to Masonry Block The plastic anchors* referenced in this plan have sufficient lateral and withdrawal capacity to handle the expected forces and are recommended because they are rated as being vibration resistant a characteristic that may be of some value under buffeting wind loads. (Standard lead anchors are not usually rated as vibration resistant.) Keep masonry anchors at least 1-1/2 inches from the block edges, joints and corners to minimize the danger of cracking the concrete blocks. Steps to Constructing Shutters 1. Use Table 2 to determine which panel to use. 2. Cut two 2x4s to a length that is 1 inch less than the width of the door opening to be covered. Rip the 2x4s lengthwise, if necessary, to the width of the distance of the door frame to the front of the wall. The outside edge of the 2x4 should be flush with the outside surface of the wall. (Note: If holes or hole plugs on the front of the building are not a concern, the top 2x4 may be eliminated by extending the shutter above the opening and attaching the top of the shutter directly to the front of the header.) Refer to Figure E1. 3. Predrill 1/4-inch diameter holes in the 2x4s in accordance with Table E1 and at least 1-1/2 inches from the front edge of the 2x4s (outside surface of the wall). 4. Drill holes in the concrete blocks. 5. Tap vibration-resistant anchors into the holes in the concrete. 6. Attach the 2x4s to top and bottom of the opening using 2-1/2-inch No. 14 round or pan-head wood or sheetmetal screws with washers. Refer to Figure E1. 7. Cut the shutter to span the opening (plus the width of the supports, 3 inches for two 2x4s). Orient the long-panel axis (strength axis) as shown in Figure 5. 8. Drill holes at 16 inches o.c. along the supported panel edges and in the 2x4s. 9. Attach the shutter to the 2x4s with 2-inch No. 10 wood or sheetmetal screws in accordance with Table E2. 10. To prevent the bottom 2x4 anchor holes in the concrete block from becoming clogged with dirt between shutter uses, insert 1/2-inch No. 14 pan- or flat-head screws into the anchor holes. Remove these screws prior to reattaching the 2x4s. 11. Any permanently installed hardware, shims or fastening devices must be installed using standard/acceptable methods of waterproofing. All abandoned holes must be sealed. 12. After fabrication, each shutter should be marked for orientation and location to speed installation. * Withdrawal ultimate value 490 lbs or greater in 4,000 psi concrete, with screws specified (1-1/2 inches with stucco).

22 Figure E1 Shutter Attachment to Header and slab floor Header Header reinforcing Anchor 2x4 No. 14 x 2-1/2" screw with washer in accordance with Table E1 TOP WEST SLIDER LEFT SIDE Outside surface of wall Alternate means of attatchment No. 14 x 2-1/2" screw with washer and anchor in accordance with Table E3 Anchor No. 10 x 2" screw with washer in accordance with Table E2 Shutter location and orientation 3/16" x 3" lag screw with fender washer 16d nails 6" o.c. APA structural panel No. 14 x 2-1/2" screw with washer in accordance with Table E1 Min. 1-1/2" Min. 1-1/2" No. 2 2x4 16" o.c. or No. 2 2x6 16" o.c. Outside of shutter No. 10 x 2" screw with washer in accordance with with Table E2 2x4 (if required) 2x4 Concrete floor Alternate means of attachment No. 14 x 2-1/2" screw with washer and anchor through 2x4 in accordance with Table E3 Anchor Patio slab Table E1 Temporary 2x4 to ConCRETE Shutter Width (ft) Mean Roof Height (ft) 33 45 No. 14 Screw Spacing (in.) 5 12 12 8 8 6 Distance to First No. 14 Screw Anchor (in.) 5 6 6 8 4 3 Table e2 Shutter to Temporary 2x4 Shutter Width (ft) Mean Roof Height (ft) 33 45 No. 10 Screw Spacing (in.) 5 8 8 8 4 4 Distance to First No. 10 Screw (in.) 5 4 4 8 2 2 Table e3 Top Of shutter TO Header (Alternate Means) Shutter Width (ft) Mean Roof Height (ft) 33 45 Concrete Anchor Spacing (in.) 5 6 6 8 4 4 Distance to First Concrete Anchor (in.) 5 3 3 8 2 2

Hurricane Shutter Design We have field representatives in many major U.S. cities and in Canada who can help answer questions involving APA trademarked products. For additional assistance in specifying engineered wood products, contact us: APA Headquarters 7011 So. 19th St. Tacoma, Washington 98466 (253) 565-6600 Fax: (253) 565-7265 Product Support HELP Desk (253) 620-7400 E-mail Address: help@apawood.org Disclaimer The information contained herein is based on APA The Engineered Wood Association s continuing programs of laboratory testing, product research, and comprehensive field experience. Neither APA, nor its members make any warranty, expressed or implied, or assume any legal liability or responsibility for the use, application of, and/or reference to opinions, findings, conclusions, or recommendations included in this publication. Consult your local jurisdiction or design professional to assure compliance with code, construction, and performance requirements. Because APA has no control over quality of workmanship or the conditions under which engineered wood products are used, it cannot accept responsibility of product performance or designs as actually constructed. Form No. T450G/Revised September 2013