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Melissa Finch, CSI, CDT
Senior Member
Username: melgfinch

Post Number: 11
Registered: 02-2024
Posted on Friday, April 19, 2024 - 11:29 am:   Edit PostDelete PostPrint Post

I'm sorry to create another thread.. I'm working on a project in Oklahoma. Most of my project experience is on the East coast, primarily Southeast. My firm previously did a project for Kansas and specified the windborne debris resistance requirements, although it wasn't a windborne region. Why? I'm not sure, I guess to have some type of protection against the tornados. Was this the right way to handle this? The structural engineer says "there is nothing special about the wind loads. the designers will need to design to code." My issue is, is that correct? Don't we want to specify some type of protection for this region/from the tornados? Any info would be helpful.
Dennis C Elrod
Senior Member
Username: delrodtn

Post Number: 36
Registered: 04-2010

Posted on Friday, April 19, 2024 - 11:55 am:   Edit PostDelete PostPrint Post

During design, we have completed projects in Oklahoma. First, is it required by Code or the Authorities having jurisdiction? Then, we always query our clients to find out if the property will be insured under FM Global's, or other Insuror's more stringent requirements. If it won't be, then we ask them how risk tolerant they are and give them some bullet points of the pros and cons. Obviously, cost is the prime factor.

Once you have done all of this, then we design accordingly.
Dennis C. Elrod, AIA
Edward J Dueppen, RA, CSI, CCS, LEED AP
Senior Member
Username: edueppen

Post Number: 99
Registered: 08-2013
Posted on Friday, April 19, 2024 - 12:33 pm:   Edit PostDelete PostPrint Post

Melissa - Dennis is correct about the thought process.

We design projects all over the midwest and it is rare we have a client that wants to spend any money on design aspects to withstand tornadoes. Even K-12 school clients generally will only go so far to design a tornado safe space within their buildings (precast concrete, concrete lid, reinforced CMU, coiling doors, etc.) rather than design an ICC 500 shelter.
Melody Fontenot
Intermediate Member
Username: melodyccs

Post Number: 4
Registered: 01-2023
Posted on Friday, April 19, 2024 - 04:42 pm:   Edit PostDelete PostPrint Post

Hi Melissa!
I lived in Oklahoma for 40 years and most projects align with typical code-required wind loads unless the Owner has requested additional requirements, and per Edward's note, it is most often a 'storm-hardened' area only, not the entire facility. You get into FEMA requirements if you are providing an actual tornado shelter. Many Owners in OK do want extra roof protection; cover boards under membranes (more for the hail), or additional roof warranty terms (to include over 55 mph winds), which can require additional roof fasteners and cost. Good luck!
Melody Fontenot, AIA, CSI, CCCA, CCS, CDT, LEED AP, SCIP
Portland, OR
Melissa Finch, CSI, CDT
Senior Member
Username: melgfinch

Post Number: 12
Registered: 02-2024
Posted on Monday, April 22, 2024 - 09:51 am:   Edit PostDelete PostPrint Post

Dennis, Edward, and Melody - Thank you for your input. This is my first project doing specs for the Midwest region so just wanted to make sure I understood what could be required here. Thank you all!
(Unregistered Guest)
Unregistered guest
Posted on Monday, April 22, 2024 - 12:42 pm:   Edit PostDelete PostPrint Post

It's best to check with the structural engineer. I understand that the 2021 IBC now includes design requirements for almost everywhere east of the Rockies. The requirements reference ASCE 7 and vary with location and building risk category.
Ronald L. Geren, FCSI Distinguished Member, AIA, CCS, CCCA, CSC, SCIP
Senior Member
Username: specman

Post Number: 1635
Registered: 03-2003

Posted on Monday, April 22, 2024 - 01:15 pm:   Edit PostDelete PostPrint Post

Refer to IBC Section 423 for required storm shelter installations. Currently, only certain Group E occupancies are required to include a storm shelter.
Ron Geren, FCSI Distinguished Member, AIA, CCS, CCCA, CSC, SCIP
Ronald J. Ray, RA, CCS, CCCA, CSI, SCIP
Senior Member
Username: rjray

Post Number: 227
Registered: 04-2004
Posted on Monday, April 22, 2024 - 07:40 pm:   Edit PostDelete PostPrint Post

Some years ago I worked on various public school project across Kansas. Some of these projects were limited to the creation of new FEMA storm shelters. As I recall, FEMA paid for 75 percent of the construction cost of these shelters.
As Ron Geren pointed out, under IBC, storm shelters were required for these Group E occupancy projects. I don't know if that was the reason for the FEMA funding or not.

I have worked on other projects in Kansas where the architects have made a token effort to create some type of "safe, feel good" space that does not meet the FEMA requirements for storm shelters. I have often wondered if, in the event of something like a tornado hitting these facilities, and these "safe" spaces to not protect the occupants of the building, if the architect has any liability from creating a "safe" space that was not actually safe.

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