Hurricanes can cause considerable damage, with wind speeds topping 150 mph. Worse than that, everything that the wind tears off of homes and other buildings becomes a ballistic object, increasing the amount of damage caused downstream. Protecting one’s home from this onslaught can be a challenge, especially protecting the windows, which are the most vulnerable part of any home.
A simple DIY plywood window protection system can make a huge difference in keeping your home and possessions safe during hurricanes. There are several ways of doing this, depending on your home’s construction, especially the type of siding and window casings you have.
Plywood is the material of choice for this, as it is the least expensive option that is still effective. Polycarbonate and metal window covering is more expensive than plywood. But it is important to pick the right kind of plywood, along with sturdy barrel bolts, specially designed clips, or other approved fasteners so that you can save money while preventing damage and aggravation.
Pre-cut plywood window covers are available in some locations. But as with any factory made part, they are made to standard sizes. This makes them much less effective than custom cut covers such as barrel-bolt plywood shutters, especially since window sizes may vary from the nominal size considerably, depending on the home builder, style of construction and materials used.
What Not To Do
We’ll talk about using plywood for hurricane protection momentarily, but first, here’s what not to do. Some unprepared home and business owners have resorted to nailing plywood sheets over windows and doors when a hurricane is approaching. Don’t do it! This can lead to more damage, as poorly attached boards are ripped off by even moderate hurricane-force winds. This makes holes in window and door frames. The plywood panels also become flying missiles, leaving your property unprotected, smashing into things, and causing worse damage.
Nails are ineffective fasteners for use in this application, as they are only held in place by compression. As the wind vibrates the plywood window covers, it would pull on the nails, loosening them. The now looser nails would allow for greater vibration in the panels, continuing to pull the nails out farther. In this manner, the wind could actually pull the nails right out of the wall.
Never use MDF, OSB or particle board for these covers, as these materials are much too susceptible to absorbing moisture. Even if you treat the wood to protect it from moisture, the relentless rain associated with a hurricane could strip the finish and be soaked into the panels, destroying them and leaving your windows without the necessary protection.
How to Make Barrel-Bolt Plywood Shutters
Barrel-bolt plywood shutters are a good option for people who want to make window covers that can be reused over and over again. They are suitable for use on homes and other buildings fitted with windows that are inset by at least two inches and made from a wide variety of materials; but they are best for home built from concrete block. According to the National Oceanic and Atmospheric Administration (NOAA), barrel-bolt plywood shutters performed extremely well even during Hurricane Andrew.
- Exterior grade plywood sheets to cover all windows and doors. When using plywood for hurricane protection, the sheets need to be 7/16 inches thick or better. Some areas have even stricter requirements.
- Be sure to check local codes to ensure that the barrel-bolt shutters you build will be in compliance.
- Take measurements before purchasing your plywood. It’s a good idea to buy a little extra in case you made a measurement error or in the event a cutting mistake happens.
- 3 to 4 inch long heavy-duty barrel bolts: NOAA recommends placing bolts at an interval of every two-feet. Other sources recommend placing bolts at six- to twelve-inch intervals.
- Electric drill – if you are going to be drilling into a concrete block, you’ll need a hammer drill with a masonry drill bit.
- Circular saw for cutting the plywood
Note: any sheet of plywood is strongest in the direction of its face grain. This is because there is one more layer of wood in that direction, than in the other direction. You always want to use the stronger direction spanning the window horizontally, if at all possible.
- The first step in making barrel-bolt plywood shutters is to prepare the plywood and the building. Be sure that you measure carefully to ensure the shutters fit perfectly. Poorly fitted shutters will not perform well.
- Carefully take the vertical and horizontal measurements inside each window casing and subtract ¼ inch. Cut the plywood to fit. If a window is not exactly square, make the panel match the actual shape of the window opening, without any gaps. A good fit is vital.
- As you fabricate each panel, use a permanent ink marker to note which side is the top and which window or door it’s meant for. This will help you to install your shutter quickly when a hurricane is approaching.
- Screw the barrel bolts to each edge of the panel. You need a minimum of one barrel bolt every two feet, along both sides. But the more barrel bolts you use, the better protected your property will be.
- Set the panel into place in the window or door frame. Mark the spot where each barrel bolt slides against the wall.
- Once you’ve made your marks, remove the panel and drill the bolt holes into the window or door recess. Use a masonry or carbide-tipped bit for concrete or stucco walls, and ensure that the drill bit makes a hole that’s large enough and deep enough to barely accommodate the bolt. You want a fit so tight that you’ll need to tap the bolts lightly with a hammer when installing the shutters.
- If you need larger panels to cover picture windows or sliding glass doors, make larger panels by connecting pieces of plywood with 2x4s. Secure the 2x4s to the plywood panels with screws at four-inch intervals.
- When the panels are finished, extend their lifespan by waterproofing them with a waterproof wood treatment or paint. Re-write your markings over the finish, if needed, and store them in a dry place, up off the floor, to prevent warping.
Using Window Tension Clips
Temporary window tension clips can be used to secure plywood to the inside face of window casings without the need for screws or nails. They attach to brick, wood, and stucco, however they do not work on vinyl siding. These clips are designed to work with only ½ inch thick plywood.
- Start by measuring your window openings and then subtract ¼ inch in both directions. Always remember that it’s better to measure twice and cut once. In this case, you’re best off running the grain of the wood horizontally in all cases, as you will only be putting the clips on the two vertical sides of the board.
- Cut the plywood to your dimensions and clean up the edges. This would be a good time to apply a waterproof sealer to the wood, in order to protect it. Oil-based wood finishes are ideal for this application, as they are easy to apply, can even be applied sloppily and will provide adequate protection for the wood.
- Mount the clips to the two vertical sides of the board, putting clips every two feet. The longer leg of the clip, with the serrated edge needs to be mounted towards the outside. These clips fit tight onto the plywood, so you’ll need to use a hammer to install them.
- To install the window covers, place the panel in place inside the window opening and push it in towards the window. In the case of a wide window, you may need to press near the sides, in order to get the clips to engage. However, you don’t want to have the plywood so tight up against the window, that there isn’t any room for it to move.
When the storm is over and you want to remove the plywood covers, press in on the plywood at one end and pull up on the toothed part of the clip. With one side of the panel loose, the panel can be lifted out and stored for the next time.
Using Screws to Mount Your Plywood Shutters
In the event your windows are not recessed far enough to accommodate either the barrel-bolt shutters or the window tension clips, you’re going to have to use screws to install the shutters. There are a large variety of different screw styles you can use for this purpose, including flush-mount anchors and hangar bolts. There are a large variety of these sorts of connectors available, each of which comes with its own installation particularities. Be sure to read the instructions before using any of them.
Rather than either of these fasteners, you’re more likely to find that screws work for your installation. The question then becomes, what type of screws? That depends on the type of material your home is made of and that those screws have to go into.
Measuring and Cutting Your Shutters
With this sort of mounting, your shutters need to be larger than the window, rather than being ¼” smaller than the window frame opening. Ideally, they should overhang onto the wall five inches all the way around. So, when you measure your window opening, add 10 inches in height and 10 inches in length to the measurement. However, if your window opening has a sill that sits out from the wall, you won’t be able to run the shutter five inches over that edge. Therefore, make the shutter only five inches taller than the window opening.
You’ll want to pre-drill the screw holes through the plywood, before using it as a template for drilling the holes into the side of your home. Always keep these screw holes 1 1/2 inches from the edges of the shutter. Start measuring at the top corners, putting the holes there 1 ½ inches from both edges, and then add holes every foot, down all edges.
Mounting in Concrete Block
If your home is made of concrete block or brick, you’ll want to either use concrete screws or screws with a metal anchor. The advantage of the metal anchor is that it can stay in your home’s wall, as a permanent mount for the shutters, should you ever need to install them again. Never use a plastic anchor for hurricane shutters, as it is not strong enough to withstand the force of the wind.
In any case, you’ll need to drill the holes for the concrete screws or the anchors with a hammer drill and a masonry bit. The right size bit will often come in the package, with the anchors or concrete screws.
With a masonry construction there is no worry that your screws or anchors are going to go into an area which will not give them the necessary structural support. The whole wall will provide the support needed so that your screws won’t pull out.
Mounting to a Wood Frame Home
If you have a wood frame home, even if it is covered with stucco, you’ll need to locate the studs inside the wall and make sure you drill your screw holes from the outside of the wall so that the screws will go through the siding and into the 2×4 studs within the wall. The siding alone isn’t strong enough to hold the screws, so they will pull out.
It’s hard to locate these from the outside of the house, so go inside and locate the studs. This should be easy, as the window casing will have a half inch thick piece of drywall, which will be mounted directly to a double stud. So, 1/2” to 3 1/2” from the edge of the window opening is all structural wood. The same can be said for the area under the window and you will have at least this much above the window.
With these dimensions located, find or make a reference point on the window that you can measure from, to find the same points from the outside of the home. a short piece of masking tape on the inside of the window should serve for this.
Select hardened screws which are at least 3 inches long for your mounting screws. It would be a good idea to put a washer under the screw head as well, even if you don’t have the right type of screws for use with a washer. The washer will help keep the screw from pulling through the plywood.
Storing Your Shutters
Once you’ve gone through the trouble of making hurricane shutters for your home, you’ll want to save them, in case there’s another hurricane. Care must be taken in the selection of a location, to protect your shutters from moisture. You’ll also want to either have them laying flat or standing on edge, upright. Never store them in such a way that the shutters are laying at an angle, as this will put a permanent curve in the wood. Then, the next time you go to use them, they won’t fit properly.
You also want to keep them off the floor, if you are storing them in your garage. There are many times when the floor of a garage might get wet, like when cleaning the garage. Setting the shutters on some scrap pieces of 2x4s will keep them off the floor, so that they don’t absorb any of this water through the vulnerable edge.
One Last Word of Advice
If you plan to make barrel-bolt plywood shutters or use a clip style system to install plywood for hurricane protection, purchase your supplies well in advance of hurricane season and build your shutters while the weather is good. Hardware stores always see a last-minute run on supplies when hurricanes are approaching. Be prepared and your home will have a better chance of surviving the next hurricane.