Frequently Asked Questions
1. What are Storm Clamps?
Storm Clamps are mounting hardware for protective storm covers. The hardware is permanently attached to a structure and is used to secure plywood over window and door openings. They are ideal for residential or commercial use.
2. What are Storm Clamps made of?
Storm Clamps are made of a glass filled nylon plastic that contains a UV inhibitor. When installed properly, Storm Clamps are as strong as steel.
3. How strong are Storm Clamps?
Storm Clamps were designed to protect an opening using four clamps, holding a 4x8 sheet of ¾” thick plywood, with 140 mph winds blowing against the back side, pushing outward.
4. How many do you need to use?
A minimum of four Storm Clamps are to be used. You may need more than four depending upon the size of the window or door opening to be covered. Storm Clamps are sold in packages of four.
5. What is the thickness of the plywood I should use?
The National Hurricane Center recommends a minimum thickness of 7/16” plywood. The maximum thickness you can use with Storm Clamps is ¾” plywood. The thicker plywood gives you better protection against airborne projectiles, but it is also heavier which makes it harder to handle.
6. What kind of tools do you need to install Storm Clamps?
A measuring tape, drill, and drill bits. We recommend the use of a hammer drill for drilling in brick or other masonry products.
7. What type of screws do you need to install Storm Clamps?
The recommendations are:
Brick structures – ¼” blue hex head masonry screws
All other structures - #12 pan head for metal screws
***Please note that for both of these screws, the base of the screw heads must be flat and be small enough to fit within the grooved portion of the base.
8. How long do the installation screws need to be?
The installation screws need to penetrate 1 ½” into the brick or solid framework of the structure. This means that if you are installing Storm Clamps on decorative shutters that aren’t well secured to the structure, the screws need to be long enough to go through the shutters and 1 ½” into the structure.
9. What colors do they come in?
Storm Clamps are available in four colors: White, Beige, Green and Brick. Storm Clamps are also paintable (Rustoleum brand primer and paint recommended).
10. Have Storm Clamps been tested?
Yes. Storm Clamps completed Debris Impact and Cyclic Load testing by the NAHB (National Association of Home Builders), in 2009.
Results: The testing showed that the Storm Clamps passed the ASTM 1886/E1996 testing for wind speeds of 130 MPH and exposure C when used following the manufacturer’s instructions on a 3’ x 6’ opening using 4 clamps. Storm Clamps, as tested in this report and when installed in accordance with manufacturer’s instructions and using a minimum #12 screw with at least 1-1/2” penetration into the wood structural frame and attaching a 19/32 inch thick wood structural panel over openings measuring 3’ x 6’ or less, meet the requirements for window protection against wind-borne debris as required in 2006 International Building Code (IBC) and 2006 International Residential Code (IRC) for structures with a mean roof height or 25’ subjected to basic wind speeds not to exceed 130 mph and exposure category C.
Click here to download the full report in PDF format.