Strengthen Exterior Doors

05/03/2023

Why do they matter?

Your exterior walls, doors, and garage doors serve as part of the protective shell of your home. If the shell breaks during a hail, hurricane, tornado, or another high-wind event, wind can enter your home and allow pressure to build on the roof and walls, often leading to damage.

Doors are one of the weakest parts of the wall, so they must be designed and installed correctly to keep wind and wind-driven rain out of a home. It is important to determine your door’s potential performance by knowing how much wind load it is designed to carry and evaluating whether it is wind or impact-rated.

Reviewing the relative strengths and weaknesses of your doors is one of the essential steps you can take to increase your home’s strength in a hurricane or other natural disaster.

What do I need to know?

Here are some questions to ask when evaluating your exterior doors and their ability to resist wind and water damage.

• What is the overall strength of the door? What is the wind rating, or highest level of positive (pushing) or negative (pulling) pressure, that it is designed to handle before breaking? Door glass panels have their own type of design pressure (DP) and impact ratings, although the ratings are very similar to window ratings.
• Is the door impact-resistant and tested to withstand debris like flying limbs or other windborne missiles so common in hurricanes?
• Which direction does the door swing? Outswinging doors enjoy more wind resistance as they have the frame’s extra muscle to help resist wind pressure.
• How is the door anchored to the door frame, and how closely spaced are the anchors?
• How is the door connected to the wall frame, and how deeply do the connections extend into the wall?
• What is the throw length and width of the deadbolt? Does it extend well into the door or wall frame?
• Does the door have glass inserts or panels? If so, are they wind- or impact-rated? If not, you will need to protect it to keep wind and water from entering your home. Is your door a single or double-entry type? While attractive, double-entry present some unique considerations in high winds:
  • Double-entry doors typically consist of an “active” door used when only one door is needed and an “inactive” door that usually remains closed but can open when necessary.
  • Double entry doors are not as strong as a single door because the frame around them is more spread out, providing less wind resistance and making them more susceptible to wind pressure and damage.
  • There are steps you can take to strengthen double-entry doors.
    • Reinforce double-entry doors by adding a heavy-duty deadbolt or replacing the existing deadbolt with a longer, stronger one.
    • Add slide bolts at the top and bottom of the inactive door. Replace the existing hinge attachment screws in the doors and door frame with longer screws that extend further into the doors and frame.

Here are some typical areas where doors can fail:

• Latch and Lock - this is a common weak point on doors as high winds can concentrate powerful forces at that single point. Many new door models feature three- and five-point latching vs. a traditional single-point latch and handle as they create a stronger door-to-doorframe connection.
• Hinges - the hinge side of the door is another potential weak point, so hinges require specific attachments to the doorframe and door to create a strong connection.
• Jamb and Frame-to-Wall - the door jamb and frame must be attached correctly to the structure to avoid door system failure, so follow the door manufacturers’ detailed specifications when you attach the system to the home.
• Threshold - the threshold is the bottom of the door frame and provides the transition from outside to inside and can be particularly vulnerable to wind-driven water. Sealing the bottom of the threshold to the door frame is essential and is often overlooked during installation.
• Flashing - Doors should be properly flashed and sealed for both wind and wind-driven rainwater. All four sides of the door should seal tightly to the frame and seal tightly to the structure.

Here are some things to keep in mind as you evaluate your doors:

• You can protect entry doors with an impact-resistant covering or by choosing using an impact-resistant door.
• You can protect doors further by covering the door opening with temporary plywood covers bolted to the door frame. This can be especially helpful if the doors contain glass panels.
• One or more entry doors should be operable from inside the living space even while opening protection is in place to ensure safe entry and exit.
• If your doors are old or damaged, consider replacing them with stronger doors by checking with home improvement stores or lumber yards.
• Heavy-duty deadbolt locks can provide extra strength for your doors as they have thicker and longer bolts, heavier strike plates, and heavier mounting hardware. Locksmiths, home improvement stores, and hardware stores can help you select and install stronger locks and slide bolts or other devices designed to strengthen and secure your doors.
• Impact-resistant doors will often have a tag or label on the edge of the door. Do not remove or paint over this label.

Where do I start?

Replacing or retrofitting your doors

• Check with your local building department for information about the wind speed rating and any possible impact rating requirement your doors should meet.
• If you would prefer not to reinforce or replace your existing doors by yourself, you can hire a professional. Home improvement, supply stores, and lumberyards often offer installation services.

More Resources:

• FLASH. Resilient Design Guide: High Wind Wood Frame Construction Edition
• FLASH. Resilient Design Guide: Concrete Construction Edition