Does the design of my house affect the design wind pressures on my garage door?
Yes. The least overall horizontal plan dimension of the structure as well as the mean roof height affect the design wind pressures on the structure.
How can I determine the wind speed requirements for my location?
The American Society of Civil Engineers (ASCE) has developed standards covering wind loads on buildings and other structures. This is the base standard for most wind provisions used in U.S. building codes. The basic wind speed maps from ASCE 7-05 or ASCE 7-10 can help an individual to determine the proper wind speed delineation zones for their area. In addition, some states such as Florida provide a listing of wind speed maps by county. For the specific requirements for your area, contact your local building official.
How do I know if my door is compliant with the wind requirements of the Florida Building Code?
The Florida Building Code has specific design pressure requirement for garage doors (table 1606.2E). Wayne-Dalton goes through the Florida Building Commission Product Approval system for many of its doors. Additional information about the Florida code can be found through the Florida Building Commission.
I am installing a new wind loaded garage door in an older home. How do I know if the building frame can support the wind loads from the garage door?
A qualified design professional such as an architect, structural engineer, or contractor should be consulted to determine if the building frame is adequate to support the loads.
I live in a 120mph wind speed region. How do I determine what wind pressures I need?
Wayne Dalton has developed the WindSafe Safety Level to aid you in determining the wind pressure needed. These tables are based on typical applications. While these are a guideline, they are not intended to cover all situations. Please contact your local building official or a registered architect or structural engineer for the specific requirements in your area. Ultimately, the engineer on record for the structure should provide the wind pressure requirements for all openings.
What effect do windows in a garage door have on design wind pressures?
Windows have no effect on the design wind pressures except in wind-borne debris regions. In wind-borne debris regions, all windows (including windows in a garage door) must be impact resistant or protected with an impact resistant covering unless the structure is designed as a partially enclosed structure.
What is the difference between wind speed and wind pressure? Why can’t you just supply doors based on wind speed alone, such as a 120 mph door?
Wind speed is a velocity measured in miles per hour (mph). Wind pressure is a force measured in pounds per square foot (psf). Wind speed alone cannot be used to determine the wind pressures on a structure. Wind speed is one of many variables used in calculating design wind pressures that take into account the structure configuration and site location.
Your drawings show the door attached to a 2x6 door jamb. How do I attach the jamb to the building frame?
Refer to the Wayne Dalton Jamb Connection Supplement for detailed information. DASMA Technical Data Sheet TDS-161 may also be used to determine how to attach garage door jambs to building framing.
Does the direction a door face affect the design wind pressures?
No. Wind can blow in any direction. Wind load design takes into consideration wind acting directly towards and away from the garage door.
I have an older door that is not a wind loaded door. Can I add reinforcement to my door to make it stronger?
A wind loaded garage door is designed with specific components, such as track, jamb brackets, hinges, rollers and reinforcing struts that meet designated design wind pressures. All of these components, along with the door sections comprise a complete wind resistive system.
You cannot add components to a door that are not part of the original door installation. By adding reinforcement to the door this does not mean it will increase the wind resistance of the door. It is also extremely dangerous because the components add weight, which can overload the counterbalance system resulting failure and possible injury.
I have heard of active (post) systems. What are they and are they acceptable by local building officials?
Active systems are any type of reinforcing system used on a garage door that requires action by the homeowner or end user to resist high wind events. Most jurisdictions in hurricane-prone regions accept active systems, but some do not. Check with your local building official for requirements in your area.
I have heard the term Exposure Category. What does this mean?
An exposure category (B, C, or D) is a condition that adequately reflects the characteristics of ground surface irregularities for the site where a structure is located. Exposure category is used in calculating the required design wind pressures for a structure with exposure B yielding the lowest wind pressures and exposure D yielding the highest wind pressures.
Exposure B applies to urban and suburban areas, wooded areas or other terrain with numerous closely spaced obstructions having the size of single-family dwellings or larger. Exposure B is typically associated with site locations in a residential subdivision. Most site locations are assumed to be Exposure B unless the site meets the definition of another type of exposure.
Exposure C applies to open terrain with scattered obstructions having heights generally less than 30 feet extending more than 1,500 feet from the building site. Exposure C includes flat open country, grasslands, and shorelines in hurricane-prone regions.
Exposure D applies to flat, unobstructed areas exposed to wind flowing over open water (excluding shorelines in hurricane-prone regions) for a distance of at least 1 mile. Exposure D includes shorelines in inland waterways, the Great Lakes, and coastal areas of California, Oregon, Washington, and Alaska. Exposure D extends inland from the shoreline a distance of 1,500 feet or 10 times the height of the building or structure, whichever is greater.
I have heard the term partially enclosed structure. What does that mean and do Wayne Dalton doors meet the requirements for a partially enclosed structure?
Partially enclosed structures are structures that are assumed to have a certain percentage of openings (such as broken windows) during a storm event. Under this assumption, the pressure inside a structure increases dramatically. This causes an increase in the design pressures on exterior walls as well.
Wayne-Dalton doors do meet these requirements, but the required design pressures for a partially enclosed structure are substantially higher than for an enclosed structure. Note that the WindSafe Safety Level tables are not applicable to partially enclosed structures.
I need to replace my existing garage door. Do I have to get a wind loaded door? Do I have to have a permit?
You will need to contact your local building official. The local authority has jurisdiction and makes the sole determination for all permitting and wind load requirements.
Is Wayne Dalton responsible for making sure the building frame can support the wind pressures imposed by the garage door?
No. As a manufacturer, Wayne Dalton is responsible for providing sufficient information through drawings or specifications that indicate the wind pressures that the garage door will impose on the structure. It is the responsibility of the design professional for the building to design the supporting structure to accommodate these pressures.
What is the difference between design pressures and test pressures?
Design pressures are the pressures required by code that a door is designed to withstand and are calculated using variables taking into account wind speed, structure configuration, and site location. Test pressures are the pressures that a door has been tested to in controlled laboratory conditions. Test pressures for garage doors have a 50% safety factor making test pressures one and a half times higher than design pressures.
Why are both positive and negative wind pressures required?
Wind can blow in any direction including away from a wall surface. In fact, negative wind pressures have a larger magnitude than positive wind pressures.