Gary & Conrad,
Thanks for the input.
Doug Mayer, SE
From: Ehrlich, Gary [mailto:gehrlich@nahb.com]
Sent: Friday, January 16, 2009 5:57 AM
To: seaint@seaint.org
Subject: RE: Wind
Doug & Conrad,
I did not see anything in a quick scan of ASCE 7-05 (provisions or commentary). However, the Wind Load Subcommittee is working on new language that would implement what Conrad said, i.e. use the same C&C wind pressure as for the adjacent wall surface. There is a paper from Peter Vickery in the May 2008 ASCE Journal of Structural Engineering that provides the necessary supporting data.
Gary
Gary J. Ehrlich, PE
Program Manager, Structural Codes & Standards
National Association of Home Builders (NAHB)
1201 15th Street, NW, Washington, DC 20005
ph: 202-266-8545 or 800-368-5242 x8545
fax: 202-266-8369
gehrlich@nahb.com
Attend the 2009 International Builders' Show
January 20-23, 2009, Las Vegas, NV
www.BuildersShow.com
From: Conrad Harrison [mailto:sch.tectonic@bigpond.com]
Sent: Thursday, January 15, 2009 7:11 PM
To: seaint@seaint.org
Subject: RE: Wind
Doug,
Typically the wind on the underside of an eaves overhang equals that on the adjacent wall surface. For example from ASCE7-05 Fig6-6 Cp=+0.8 for the windward wall, so soffit would experience Cp=+0.8 (upwards), whilst sidewalls experience Cp=-0.7 (downwards), and leeward Cp=-0.5(max. mag.) (downwards). Adopt similar approach for C&C pressures.
Not sure where rule is in ASCE7 but it is the approach used to AS1170.2, and I recollect something in commentary to ASCE7-05.
Regards
Conrad Harrison
B.Tech (mfg & mech), MIIE, gradTIEAust
mailto:sch.tectonic@bigpond.com
Adelaide
South Australia