Protect existing or not

[mtlogcabin]

Existing single story hospital portion constructed in the mid 70's as a Type IIA. Every addition after that has been Type I A. The hospital is now proposing a 3 story addition over the existing Type IIA completely structurally independant of the original construction. The original columns and beams supporting the original roof will remain. The combustible roofing materials will be removed but the beams and metal deck will remain.

Question: Should the primary structural frame of the original construction be protected as a Type IA OR should it be left as is?

2009 IBC

PRIMARY STRUCTURAL FRAME. The primary structural frame shall include all of the following structural members:

1. The columns;

2. Structural members having direct connections to the columns, including girders, beams, trusses and spandrels;

3. Members of the floor construction and roof construction having direct connections to the columns; and

4. Bracing members that are essential to the vertical stability of the primary structural frame under gravity loading shall be considered part of the primary structural frame whether or not the bracing member carries gravity loads.

The goal is to have a Type IA building when this addition is complete

 

[Coug Dad]

I consulted on one of these a few years ago. I warned them of the problems and code issues, but the wanted to go down that path anyway. Once they got into it, they realized what a bad idea it was. The code does not allow for different construction types. The whole building should be brought up to the desired construction type or separated with fire walls. They have to be careful about variances or equivalencies unless they include CMS in the approval process.

 

[High Desert]

The code does allow for different types of construction with a firewall (Section 706.1). But with mtlogcabin is descibing sounds like they don't have that condition. In order to make the entire building a Type IA, the entire structural frame would have to meet the Type IA provisions of Table 601. Otherwise, it would revert to the lesser construction Type IIA.

 

[Neville]

Thanks guys..

The suggestions discussed in this forum are very real in nature and very practical in approach as I am also planning to buy some property and have no knowledge in the field but after reading this forum discussion i am feeling quite confident to make a successful deal.