2 hour firewall question...

[A930Rocket]

Any commercial builders here?

We are in one suite and are expanding into the suite next door, but it has a 2 hour firewall between units.

Can we cut through the firewall and install a 2-hour rated door? With a door closer maybe?

I’ve looked online and have read that we can use a 1-1/2 hour door or higher, but just wanted to get your thoughts.

Thanks!

[id10t]

And here I was reaching for my iptables books...

Not a builder... but I would imagine it would have a lot to do with local code.

[Rtrorkt]

2 hour wall requires a "B" Labeled fire door. Typically rated at 90 minutes, though the occupancy designation and construction type for each suite and the building will dictate. It must be the full assembly, door, frame and hardware rated the same

[tcar]

Originally Posted by Rtrorkt

2 hour wall requires a "B" Labeled fire door. Typically rated at 90 minutes, though the occupancy designation and construction type for each suite and the building will dictate. It must be the full assembly, door, frame and hardware rated the same

...yes... and hardware includes closer.

[A930Rocket]

That was my understanding. The door had to be 75% of the wall and self closing.

Now we just need to determine the wall thickness and door jamb.

[Rtrorkt]

Originally Posted by A930Rocket

That was my understanding. The door had to be 75% of the wall and self closing.

Now we just need to determine the wall thickness and door jamb.

i am doubting the door is 75% of the wall. There will be an opening limit in the wall given the construction type. Yes, with closer. Wall thickness in a rated situation is most likely 3 5/8" metal studs with 2 layers of 5/8" drywall both sides

from Ceco

https://www.cecodoor.com/en/site/cecodoor/products/standard-fire-doors/steel-stiffened-core-doors/

And hardware
https://www.yalecommercial.com/en/yale/yalecommercialcom/site-functions/search/?searchquery=fire+rated

typical wall assembly, non-load bearing interior partition

USG Design Studio | UL U404 Configuration A - Fire Resistant Assembly, Fire Rated Assembly, Fire Rated Detail

[tcar]

Originally Posted by Rtrorkt

i am doubting the door is 75% of the wall...

He's saying the door RATING is 75% of the wall RATING... not talking about size, I don't think..


And door rating is not always 75% of the wall rating... just happens to be in this case.

[A930Rocket]

Rtrorkt

I was looking at the table again and you’re right. I just got lucky on this one.



I hope the picture above looks better on a pc or laptop than my phone.

[Rtrorkt]

Originally Posted by tcar

He's saying the door RATING is 75% of the wall RATING... not talking about size, I don't think..


And door rating is not always 75% of the wall rating... just happens to be in this case.

OK, can see that. There are times where a 2 hour wall allows a 90 minute door ("B" labeled) and other times where a full 2 hour door is needed, "A" label. That condition is rare

[tcar]

Sometimes a 1 hour wall only needs a 20 minute door, for instance.

[Rtrorkt]

Originally Posted by A930Rocket

Rtrorkt

I was looking at the table again and you’re right. I just got lucky on this one.



I hope the picture above looks better on a pc or laptop than my phone.

Looks like you are good, 2 hour wall, 90 minute B labeled door with appropriate hardware, frame and closer. Local jurisdiction might ask for gasketing to prevent smoke/fire migration, but that will be a local requirement. Good luck

[dyount]

You are absolutely correct using Table 715.4 and it's requirements. Now I'll wade in with a different pile of questions.
Are you in a strip mall possibly that isn't sprinklered? If so, they may have had a requirement to keep fire areas below a certain size in order to not sprinkler, therefor a fire barrier.
Easy answer would be to just put in a 1.5hr door and move on but there's also a question of egress from/between spaces, door swing etc.
Feel free to pm me and I'll shoot you my business email. You could email me a floor plan of the building to take a look at if you'd like. BTW, I'm not looking for payment etc... Just rather offer professional advice to a fellow Pelicanite. I'm a ICC Master Code Professional and review and inspect for a living and I'd be glad to help

[A930Rocket]

Thanks dyount.

This is a building of light commercial units. There’s probably 10 businesses here and the units are about 29’ wide and 96’ deep.

No sprinkler system.

There is a 3/0 outdoing door front and back of each unit. Plus a roll up metal garage door in back.

The new door will be in the kitchen of each unit. The door will be a 3/0 left hand swinging into the right side unit.

I’ll send you a PM to send plans.

Thanks!