In order to properly design for wind attachment a basic understanding of the effects of winds on buildings is required.
Roof design wind.
This includes structural components such as roof sheathing or rafters or roof cover components and the connections of these elements.
And with the latest version of asce 7 minimum design loads for buildings and other structures asce 7 it has become that much more challenging for roof system designers and roofing contractors.
Roof damage caused by wind occurs when the air pressure below the roofing assembly is greater than the air pressure above the building s roof.
Wind damage to buildings can range from complete demolition of the structure to total or partial roof displacement blow off to damage to penetrations skylights mechanical equipment vents etc doors and windows.
The basic design wind speed v mph corresponds to a 3 second gust speed at 33 above ground in exposure category c and is associated with an annual probability of 0 02 of being equalled or exceeded 50 year mean recurrence interval.
A dfcm roof history record is required on all roofing systems contractors responsibility.
Please note that a 1 90 or a 1a 90 rating does not provide the necessary wind speed requirements.
Wind design of roof systems is one of the more complicated things that an architect deals with during the design of a building.
Minimum wind speed in known high wind areas.
Refer to local wind speed maps for other wind speed design requirements.
Roof wind designer is intended to provide users with an easy to use means for determining roof systems design wind loads for many commonly encountered building types that are subject to building code compliance.
Roof wind designer initially was developed in cooperation with the midwest roofing contractors association and north east roofing contractors association.
Roof design wind loads are the wind pressures and resulting uplift forces for which the roof structure is designed.