If you’re a glazing contractor or a building envelop contractor; an estimator or project manager, you’ve probably tried to size your storefront and curtain wall members off of a wind design pressure.
The wind design criteria are usually given on the contract structural drawings. Sometimes design wind pressures for components and cladding are given as well. However, the changes with the 2012 IBC have created much confusion regarding the actual design pressures to be used.
Many times the components and cladding pressures listed on the structural drawings are given in terms of “Ultimate strength design”, which is not used in any of the wind load charts given by manufactures. Using these pressures will ultimately lead to overly conservative design.
Designers need to be able to calculate the allowable strength design loads from the information given off of the structural drawings.
If you have a question about what is on a structural drawing, give us a call.