tbz
Silver Member
Good evening all,
I am working with a client's engineer on a project and they are hung up on the following question that has been sent in to ASCE-7, with a response that they will have a subcommittee get back to us, well I am not sure when that will be so I am posting the question below looking for input and possibly a direction to another forum that can help.
The engineer's question:
"We are designing a railing for balconies and other areas on a shoreline building in New Jersey. The railing includes glass infill panels. The 2015 version of the NJ building code section 1609.1 Applications reads as follows:
1609.1 Applications
Buildings, structures and parts thereof shall be designed to withstand the minimum wind loads prescribed herein. Decreases in wind loads shall not be made for the effect of shielding by other structures.
1609.1.1 Determination of Wind Loads
Wind loads on every building or structure shall be determined in accordance with Chapters 26 to 30 of ASCE 7 or provisions of the alternate all-heights method in Section 1609.6. The type of opening protection required, the ultimate design wind speed, Vult, and the exposure category for a site is permitted to be determined in accordance with Section 1609 or ASCE 7. Wind shall be assumed to come from any horizontal direction and wind pressures shall be assumed to act normal to the surface considered.
The 2010 version of ASCE7 (ASCE 7-10 ) is the applicable ASCE 7 standard. Because the glass forms a substantial part of the railing surface, and because wind loads in NJ at the coastline are substantial, we are examining the effects of the wind on the railing.
I have not found any specific way to address a glass railing at a balcony in ASCE7-10. A glass railing at a roof top would certainly have to be addressed as a parapet, applying the positive wall pressure and the negative roof pressure in combination. Because there is a building a few feet behind our glass railing, intuitively, this same approach may be excessive if applied to the glass at the balcony. Furthermore, in our project we have been provided only with the wall (components and cladding) wind loads and a roof wind load. There are no wind loads generated for uplift/suction at the balconies. Each balcony is relatively small I relation to the building (approximately 10 feet wide, projecting 14 inches from the building façade).
Can you provide guidance as to which provisions of ASCE 7 apply to determine the wind load for a glass railing at an apartment balcony?"
That is the question above and some more background information below:
I am working with a client's engineer on a project and they are hung up on the following question that has been sent in to ASCE-7, with a response that they will have a subcommittee get back to us, well I am not sure when that will be so I am posting the question below looking for input and possibly a direction to another forum that can help.
The engineer's question:
"We are designing a railing for balconies and other areas on a shoreline building in New Jersey. The railing includes glass infill panels. The 2015 version of the NJ building code section 1609.1 Applications reads as follows:
1609.1 Applications
Buildings, structures and parts thereof shall be designed to withstand the minimum wind loads prescribed herein. Decreases in wind loads shall not be made for the effect of shielding by other structures.
1609.1.1 Determination of Wind Loads
Wind loads on every building or structure shall be determined in accordance with Chapters 26 to 30 of ASCE 7 or provisions of the alternate all-heights method in Section 1609.6. The type of opening protection required, the ultimate design wind speed, Vult, and the exposure category for a site is permitted to be determined in accordance with Section 1609 or ASCE 7. Wind shall be assumed to come from any horizontal direction and wind pressures shall be assumed to act normal to the surface considered.
The 2010 version of ASCE7 (ASCE 7-10 ) is the applicable ASCE 7 standard. Because the glass forms a substantial part of the railing surface, and because wind loads in NJ at the coastline are substantial, we are examining the effects of the wind on the railing.
I have not found any specific way to address a glass railing at a balcony in ASCE7-10. A glass railing at a roof top would certainly have to be addressed as a parapet, applying the positive wall pressure and the negative roof pressure in combination. Because there is a building a few feet behind our glass railing, intuitively, this same approach may be excessive if applied to the glass at the balcony. Furthermore, in our project we have been provided only with the wall (components and cladding) wind loads and a roof wind load. There are no wind loads generated for uplift/suction at the balconies. Each balcony is relatively small I relation to the building (approximately 10 feet wide, projecting 14 inches from the building façade).
Can you provide guidance as to which provisions of ASCE 7 apply to determine the wind load for a glass railing at an apartment balcony?"
That is the question above and some more background information below:
- IBC 2015 NJ - ASCE 7-10
- Basic Wind Speed = 121 MPH
- Risk category - II, Exposure D