Retrofits for Garage Doors
Evaluate your risk
Garage doors are usually the biggest opening on your house and the survival of your garage door is important to the survival of your house. When evaluating your house for its vulnerability to hurricanes, you need to consider your garage door as one of the first and most important vulnerabilities. Doors can be pushed in by winds blowing onto the door or pulled out as winds whip around the corner of the house where the door is located. Garage doors tend to be at the corners of the house, where the outward acting pressures (suctions) are greatest. Larger doors have more surface area exposed to wind and the door spans a much greater distance, so two car garage doors are more vulnerable than single car doors.
Failure of the garage door allows the full fury of the hurricane to enter the house and act on interior walls, doors, ceilings or roofs that form the barriers between the inside of the garage and the rest of the house. This frequently leads to failure of these surfaces and can lead to significant loss of roof sheathing or loss of a part of the roof.
The two threats to your garage door are wind pressure and wind borne debris. Ensuring the door is strong enough to resist wind pressure is critical, while impact resistance to wind borne debris is also especially important for garage doors with windows.
Garage door pulled out by the wind.
The failure of this garage door probably contributed to the loss of roof sheathing.
Evaluate your garage door
Look for a label on the door indicating the design pressure rating. Some doors have a removable brace that is to be installed when a hurricane threatens. These doors will usually have a label that indicates the rating with the post in place. Check with your local building department to make sure the garage door design pressure rating is suitable for your location. If there is no label, look for the following signs of a weak door:
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Does your garage door only have one bar across each of the four panels or maybe only one or two panels have bars?
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Is your garage door made of wood?
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Are some of the door panels rusted or rotted?
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Are some of the door panels badly dented?
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Are the brackets that hold the track to the wall loose, broken, or missing bolts or nuts.
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When the garage door is closed, do the brackets supporting the track line up with the rollers?
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Are the hinges between panels loose, broken, or missing bolts or nuts or screws?
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Are the rollers plastic and/or are the axels through the rollers hollow?
If any of these seven items is true, the garage door will likely perform poorly when a hurricane strikes and you should retrofit or replace your garage door.
Consider options for retrofitting your garage door:
Option 1
Install after-market vertical braces that are code approved and available at a local home improvement store. These braces have do-it yourself instructions, but you could also hire a handyman to install the braces for you. Two or three braces are usually needed on two car garage doors. These braces cost about $150 each. It should be noted that this retrofit option does not address impact protection, so if your garage door has windows it is still vulnerable to wind borne debris.
Option 2
Check with the door manufacturer for a kit to strengthen the door and its track so that it has the properties found in new wind-rated doors appropriate for your location. Retrofitting an existing door to withstand high wind involves strengthening the panels, tracks and rollers and recalibrating the springs. The cost of the retrofit is likely to run between $450 and $600 for a two car garage door. Again, this retrofit option does not address impact protection, so if your garage door has windows it is still vulnerable to wind borne debris.
Option 3
Replace the door with one that is pressure or pressure and impact-rated. This may be the simplest solution, especially if the door is deteriorated and is in need of replacement. Replacing the door with a pressure or pressure and impact rated door may be the most cost effective solution in the long term. Although many areas don’t require impact rated garage doors unless there are windows in the garage door, some local jurisdictions do. All impact rated garage doors must meet the requirements of approved test standards like the Large Missile Test of ASTM E 1886 and E 1996, the Florida Building Code standards TAS 201, 202 and 203, or ANSI/DASMA 115.
Option 4
Install an opening protection product over the garage door. If your door is relatively new then a shutter system may be the best route. On the other hand if the door is deteriorated and is in need of replacement then replacing the door will be the most cost effective solution in the long term. All impact rated shutter systems for garage doors must meet the requirements of approved test standards like the Large Missile Test of ASTM E 1886 and E 1996 or the Florida Building Code standards TAS 201, 202 and 203. See the IBHS shutter guide for more information on shutters for garage doors.
Important note: If an opening protection insurance discount is one objective of your retrofit, you should check to make sure that you will be able to obtain a letter certifying the compliance of your retrofitted door that will acceptable to the insurance company. You may be better off replacing the door with a rated product that has an official label if you want to ensure that you will get any available insurance discounts for protecting all openings.
Purchasing a replacement garage door
Look for a garage door that is code approved for both wind pressure and impact protection.
When you are selecting a garage door there are two primary considerations. One is to be sure the door is rated for the correct wind pressure for the design wind speed of the area in which you live. The other is to select a door, at additional cost, that is also impact rated. Such a door provides the best level of protection and is a prudent choice. The cost of a pressure rated, impact resistant two car garage door is around $1500. Some jurisdictions, notably Miami-Dade and Broward counties in Florida, require that the garage door be pressure and impact rated regardless of whether it has windows or not. In most other coastal areas that are part of the windborne debris region defined by the American Society of Civil Engineers (ASCE) Standard 7 as areas with design wind speeds of 120 mph or greater or areas with design wind speeds of 110 mph or greater that are within 1 mile of the coast, the garage door has to be pressure rated, but if the garage door includes windows it has to be pressure and impact rated. Otherwise, the code requires that the garage door be pressure rated – that is, rated for the design wind pressure appropriate for that location. Design pressure rated only (not impact rated) garage doors cost around $800-$1000. The table below provides guidance for minimum positive and negative design pressures (DP) that are required for garage doors in the 2005 ASCE 7 standard. Check with the local building department to determine what the required design pressures (DP) are for the garage doors in your location. Make sure you install garage doors that meet the required design pressure (DP) rating.
| Basic Wind Speed (MPH) | ||||||
| Effective wind area (ft2) | 100 | 110 | 120 | 130 | 140 | 150 |
| 50 (Single car) | 16, -18 | 20, -22 | 23, -26 | 27, -30 | 31, -35 | 36, -40 |
| 100 (Two car) | 15, -17 | 19, 21 | 22, -25 | 26, -29 | 30, -33 | 35, -38 |
Notes:
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Impact rating standards for garage doors
All impact rated garage doors must meet the requirements of approved test standards like the Large Missile Test of ASTM E 1886 and E 1996, the Florida Building Code standards TAS 201, 202 and 203, or ANSI/DASMA 115.
