Maybe I'm reading this wrong too, but could they be talking about running a duct in a chase (from a basement to an attic or another floor), sealing the gap so that fire can't go up that chase?
Can someone turn this into english: "when supply or return ducts pass through the floor, a 1/4 inch thick nocombustible resilient gasket must be used between the duct, unit and floor."
I'm also trying to figure out why most of the jobs I see don't have this gasket.
Why wouldn't register boots in floors/walls/celings need a gasket like this or does mastic sealant qualify.
None of the uppers I have talked to can explain this very good. Thanks for any help.
Maybe I'm reading this wrong too, but could they be talking about running a duct in a chase (from a basement to an attic or another floor), sealing the gap so that fire can't go up that chase?
Filling the gap in the stud cavity around the duct would make sense. I think that is what they're talking about. Where is building code when you need him
you usually have to flash (firestop) it off and fire caulk it.
FILL OUT YOUR PROFILE!!
For the sake of clarity can you define 'firestop' ,and why in the heck would one only have to do this occasionally if it is that important.
i don't know where you're from because YOU DIDN'T FILL OUT YOUR PROFILE. around here... when you penetrate a top/bottom plate you have to put break angle metal when the plate used to be and firecaulk the rest of the penetration next to the duct (metal of course). stoppping the smoke/fire from going from one floor to another.
FILL OUT YOUR PROFILE!!
Tried editing my profile one time , but the site was unresponvsive (sluggish)...obviously it didn't work. I'll try again though. St. Louis is where I be. No inspectors, nothing, I must figure out the code/regs/right-way-to-do-it on my own, and of course from HVAC-Talk. Thanks
that's why we're here
FILL OUT YOUR PROFILE!!
Hey Tinner or whomever,
If Stl doesn't have mechanical inspectors then would this code be enforceable. Public works is uncapable of disseminating information about regulations or codes for installing HVAC systems. Where is the line drawn when there is such a gray area in the city government??? Maybe someone out there has experience with situations like this.
Mechanical Inspectors most towns don't have them.
What wrong with just caulk or fire caulk?Thats is what most of us do.
I know this is in the residential section, but this is in a residential house right?
In our commercial jobs, whether there's a fire/smoke damper or not, we have to angle around the duct and fire caulk it. Residential we don't, but I typically at least flash it in with angle... part fire stop, part easy hanger system ='s good reason to do it.
Yes it is a resi building. Companies here use entire stud cavities w/o ducting as returns from the second floor to the return trunk in the basement and no firestop obviously. I guess it's legal.
In wv where I live they use the walls as duct or pan it for returns only when I lived in nc you couldn't do that you need to take to someone in you area.No one else will be able to help you.
[Edited by framehvac on 02-22-2005 at 01:01 AM]
your post is as hard to understand as my last one...i hope you don't wake up each morning to be like me.
things sure have changed in 60y in StLouis, MO, then! in the late 1940s, everything had to be inspected in St Louis & in County!
anyway, it would be a good idea to seal any vertical cavity against air flow -- best if firestopping material is used -- critical if multiunit= apt or condo complex! else, it is a lawsuit awaiting.
typically firestopping and angles are only required around a duct opening when the duct is passing through a 1 hr rated assembly. when you pass through a two hour rated assembly a fire damper is needed. most likely the residence is wood construction and the walls and floors are not fire rated.
I wonder if it is referring to a supply or return plenum in an effort to make sure combustable floor base is used in a downflow position or an upflow where the return is cut into the floor below the furnace.
I usually see it in upflows located in the basement where the return uses the floor joists to link the return trunk to the inside wall via cutting the baseplate (and topplate for the second floor). Register is then placed on the 1st floor drywall and the wall cavity becomes the return. St. Louis public works can't tell me if it is code or not...they don't bother with resi. I guess it's okay because wood floors aren't fire rated like the previous poster noted.
I'm going to follow IBC and IMC code and everything should go Okay.
wood floors may not be fire rated, but toxic gases flow thru any opening, even flames --
BTW, toxic gases kill within 3 breaths, normally --
one has about 6 min to get out of a bedroom above a room below having just a waste basket fire --
and, think about infiltration