I am currently working on a rehab of a 6 story residential (R-2) apartment building that was constructed around 1964-65. The exterior brick veneer has failed due to numerous reasons of poor workmanship and lack of expansion joints. Behind the brick is 4” cmu and plaster. The owner wants to replace the entire exterior wall assembly with metal studs and exterior finish panel.
My question is back when this was built the primary framing was not required to be rated. The floor and ceiling assembly is noted on the drawings to have a 3 hr. rated assembly. See attachment. In the renovation a full NFPA 13 sprinkler system will be installed. The scope of work will put the project to Level 3 Alterations. I reviewed the Existing Building Code and what I am reading is that replacement should not decrease the level of safety. The exterior wall does have some rating but stops at the beam.
Here is my code interpretation based on building a new building base on NY 2020 Building Code. I classified the building as 1B because the building exceeds the allowable number of stories of 2B.
Primary and Secondary Steel – 2 Hrs.
Exterior Wall >30’ – 0 hours.
What would be the proper way to address this? Because there is no rating now is it acceptable to leave it? Does the new wall need to be similar rating and stop at the underside of the beam? Do I fire rate the beam with a ul listed gypsum enclosure that extends to the rated ceiling assembly?
My question is back when this was built the primary framing was not required to be rated. The floor and ceiling assembly is noted on the drawings to have a 3 hr. rated assembly. See attachment. In the renovation a full NFPA 13 sprinkler system will be installed. The scope of work will put the project to Level 3 Alterations. I reviewed the Existing Building Code and what I am reading is that replacement should not decrease the level of safety. The exterior wall does have some rating but stops at the beam.
Here is my code interpretation based on building a new building base on NY 2020 Building Code. I classified the building as 1B because the building exceeds the allowable number of stories of 2B.
Primary and Secondary Steel – 2 Hrs.
Exterior Wall >30’ – 0 hours.
What would be the proper way to address this? Because there is no rating now is it acceptable to leave it? Does the new wall need to be similar rating and stop at the underside of the beam? Do I fire rate the beam with a ul listed gypsum enclosure that extends to the rated ceiling assembly?