Hurricane Shutters

Garage Doors

Inspection Services

OCS Link

Myth:

Garage doors have little impact other than overall look of the home.

Truth:

A garage door can impact your insurance costs, heating/cooling costs, and value of the home.

 

Residential & Commercial Windload Guides

DASMA Technical Data Sheet #155

DASMA has developed, and continues to develop, a number of resources to assist those connected with the building industry by clarifying the relationship between wind loads and large doors such as garage doors and rolling doors. These resources are intended to aid in the process of specifying these types of doors for buildings, which would result in effective resistance to required wind loads in specific applications.

One prominent approach DASMA has taken is to publish documents that contain wind loads specific to garage doors and rolling doors. The first such “wind load guide” was based on the wind load provisions of the Standard Building Code, because of the high susceptibility to hurricane-induced high wind events in the areas that predominantly adopt and enforce the SBC. Because DASMA recognized that non-tornadic high wind events could occur anywhere in the U.S., subsequent wind load guides have been released based on other U.S. building codes.

Many of the guides for a particular code are subdivided by “Exposure” categories. Pre-1999 codes and standards define these “Exposures” as follows (source: ASCE 7-93):

B: Urban and suburban areas, wooded areas, or other terrain with numerous closely spaced obstructions having the size of single-family dwellings or larger.
C: Open terrain with scattered obstructions having heights generally less than 30 feet.
D: Flat, unobstructed areas exposed to wind flowing over large bodies of water.

Exposure conditions C and D have been redefined via the publication of ASCE 7-98. In this document, shorelines in hurricane-prone areas are now considered “Exposure C”, and shorelines qualifying as Exposure D are more clearly described (inland waterways, the Great Lakes and coastal areas of California, Oregon, Washington, and Alaska.) It is also now widely held that Exposure B should be assumed unless another Exposure can be clearly determined in accordance with the guidelines described in the code or standard being applied.

DASMA is committed to accurate and complete information that can be understood by all interested parties, along with a dedication to a nationwide view concerning their products. Furthermore, DASMA is committed to keeping abreast of continued code development by updating and creating “wind load guide” information whenever needed.

.