Need NEC/NFPA expertise - fireblocking in chase

Neurorad

Neurorad

Senior Member
Briefly, I'm cutting into a chase, attic to basement, surrounding the fireplace flue, to install conduit (e.g. Carlon Resi Gard).

There is, what looks like, particle board at each floor, providing fire blocking at each level. Obviously, when I cut through this, I'll need to use fire-rated caulk around the penetration.

The chase is surrounded by drywall on 4 sides. If I cut into this drywall for access to the chase, can I install any plastic access panel, or do I have to replace drywall?

I think the fire rating requirements are only for the floor level penetrations - correct?

Thanks!

Edit - I don't want to repair drywall in my wife's closet if it can be avoided. She said she wouldn't mind the panel, behind clothes.
 
Neurorad said:
Briefly, I'm cutting into a chase, attic to basement, surrounding the fireplace flue, to install conduit (e.g. Carlon Resi Gard).

There is, what looks like, particle board at each floor, providing fire blocking at each level. Obviously, when I cut through this, I'll need to use fire-rated caulk around the penetration.

The chase is surrounded by drywall on 4 sides. If I cut into this drywall for access to the chase, can I install any plastic access panel, or do I have to replace drywall?

I think the fire rating requirements are only for the floor level penetrations - correct?

Thanks!

Edit - I don't want to repair drywall in my wife's closet if it can be avoided. She said she wouldn't mind the panel, behind clothes.
Click to expand...
This is a building code question, not an NFPA or NEC question. Building codes vary all over the country. Many states use the IBC, the one I am most familiar with. The IBC requires a 1 inch clearance around masonry chimneys and manufacturer's requirements apply for chimney lining systems. (Contact with combustible material may be allowed in this case). However, in either case, fireblocking with non-combustible material is required at floors and ceilings (not particle board).

I don't think the Carlon Resi-guard would be classified as non-combustible. Also, I believe you would compromise the fireblocking if you cut a hole to penetrate with conduit, even if you fire caulked. But maybe your inspector would allow the use of IMC (intermediate metallic) or RMC (rigid metallic) conduit.

To be sure, it would be best to discuss this with your local building inspector. Many times they have time slots set aside to answer questions on the phone.
 
I spoke on the phone with the local inspector last week, for about 20 minutes. He was very helpful, answering a multitude of questions.

I just had this idea, though, about using an access panel to avoid drywall repair, in the wife's closet.

I will ask him specifically about the access panel.

I found some access panels (Accudoor), fire rated, $120 for 14" x 14". I think that will do the trick. (Edit - Acudor, not Accudoor, sorry)

The inspector sounded very positive about the use of Resi-gard, without being familiar with the product.

We talked about fire-resistant caulk at each of the floor penetrations, and the distance of the conduit from the metal flue (specified as 6" by Carlon).

He told me he did the inspection for my home when it was being built 14 years ago, so he was the one that OK'd the particle board, separating the chase from the attic space. Maybe he missed it, but I think particle board would be OK - I think it's just generic drywall surrounding the chase anyway.

By the way, I was pretty surprised when I saw the size of the chase - I think it is ~ 6' by 6', on the second floor, above the gas fireplace. Keeping 6" away from the metal flue will be a breeze. I'll take some pics, when I cut into more walls.
 
Neurorad said:
He told me he did the inspection for my home when it was being built 14 years ago, so he was the one that OK'd the particle board, separating the chase from the attic space. Maybe he missed it, but I think particle board would be OK - I think it's just generic drywall surrounding the chase anyway.
Click to expand...

Wow. We need more building inspectors like him in my town. The ones around here can't even remember what I was asking for just two weeks ago, little less 14 years ;)

--Jamie
 
Do you have a link to the Fire Rated access panel? I wanted to get into the attic in my garage. As the garage is touching living space in this area, there is drywall everywhere (fire-wall). I'd like to be able to install a door like this so I don't have to re-drywall each time I need to go up there (shouldn't really ever need to...but hey...you never know right?

--Dan
 
drozwood90 said:
Do you have a link to the Fire Rated access panel? I wanted to get into the attic in my garage. As the garage is touching living space in this area, there is drywall everywhere (fire-wall). I'd like to be able to install a door like this so I don't have to re-drywall each time I need to go up there (shouldn't really ever need to...but hey...you never know right?

--Dan
Click to expand...
I've been doing a lot of reading on fireblocking and firestopping.

Fireblocking is mostly a commercial requirement, while firestopping blocks the flow of oxygen/air.

In a garage, you're not supposed to have a penetration greater than 6 square inches, about a double gang box.

If it's a 'fire rated' door, I think it would be OK.

I'm not a house inspector, or insurance claims adjustor, so don't take my word for it.

Here is a link to an Acudor: http://www.pexsupply.com/Acudor-FB-5060-12...-Door-6791000-p
Your local plumbing supply shop should carry this, or something similar. You can take a look at it before buying, and prices are usually competitive with online.

I'm still researching my problem of conduit in the chase...

Edit - and I'm certain the particle board is a 'no-no' for firestopping - I'll replace what I can.
 
'Have fun' sounds sarcastic - I've already spent many, many hours pouring through online docs. ;)

I'll search through the Hilti website - I've come across that name a few times, on other forums, for firestopping caulk specification. Thanks for the tip!

Edit - Those links, Gatchel, take me to the Hilti homepage, but I've found some good stuff there. I didn't need to register, for some reason.

Edit #2 - I registered, and found more stuff. Thanks again!
 
So...how/why did people choose Carlon Resi Gard over Carlon Riser Gard?

Because of my floor penetrations, I think Riser Gard might be the best option - whatever I choose, I'll have the inspector clear it before buying.

Riser Gard is similarly priced to Resi Gard ($180/100 feet vs. $86/50 feet, local electric supply store). Why not?

Anyone cap or plug their conduit - rock wool, caulk, special plug?
 
Neurorad said:
'Have fun' sounds sarcastic - I've already spent many, many hours pouring through online docs. :p

I'll search through the Hilti website - I've come across that name a few times, on other forums, for firestopping caulk specification. Thanks for the tip!

Edit - Those links, Gatchel, take me to the Hilti homepage, but I've found some good stuff there. I didn't need to register, for some reason.

Edit #2 - I registered, and found more stuff. Thanks again!
Click to expand...

Sarcasm at its best. :blush: I started looking through some of the Hilti docs and found everything but residential information. I really wanted to give you a more direct link but could not get there in the amount of time I had at that moment. I'm glad you found what you needed.
 
I think it will all boil down which flexible conduit the inspector will allow. I think I'd feel a little safer with Riser Gard, than with Resi Gard.

He may want me to use electrical nonmetallic flexible tubing (ENT/Smurf Tube), because he's familiar with it, and it has higher ratings (greater testing has been done on ENT compared with the Resi/Riser Gard, and it has a higher temperature rating). But it's also much more expensive.

I will pay particular attention to penetrations - fire rated culk/foam.

The inspector will tell me what fire rating an access panel should have, in that chase location. I'm guessing 1 hour, similar to drywall. Acudor FB-5060, 16" x 16" is rated 1.5 hours, and costs ~$115.

I doubt it's 5/8" drywall (Type X, what should be lining my chimney flue and basement furnace chase, and all garage walls/ceilings), but I'll find out when I cut into it. 5/8" drywall is 1 hour rated. Standard 1/2" drywall is 1/2 hour rated. In addition to thicker, Type X has a denser core and contains glass fibers that keep it from crumbling in the heat.

I think the inspector, and the whole office, took the day off - nobody answering the phones.

The size of the access door will depend on how much weight I can lose by the time of installation. :blush:
 
Are you doing a basement to attic 'main trunk'? If this is the case you'll need something like a 2" piper or something and i think you'll want something solid, so you don't hang up on the ribs of the flexible.

A 3/4" flexible conduit won't hold much. maybe 3 RG6QS OR 5 Cat5's IF you pull them all together. 3/4" is good for 'drops' to a particulart end point, but not a main trunk. Maybe you found something bigger than 3/4" and this is a useless post. :blush:

I have 2 2" PVC piper going straight up. The builder left them with 'caps' on them. After i run the cables i'm supposed to put a firestop of sorts instead of the cap (caucking or rockwool or something).

Even 2 2" isn't a whole lot if you're planning to run some serious cable.
 
Thanks, MavRic.

If I can get away with the Resi Gard, I'll buy 3 coils of 50', 2" dia.

If I have to buy 2 100' coils of Riser Gard, I'll put in 4 runs of 2".

I estimate, at most, about 30' per drop.

If I must install ENT (most expensive option), at the insistance of the inspector, I'll go with 3 runs of 2". My local electric supply shop will sell it to me by the foot.

Resi Gard and ENT are in stock, Riser Gard will have to be special ordered.

I'll find out soon about the amount of space in the chase on the first floor, behind the chimney. On the second floor, the space was huge, ~6' square.

Thanks to Gatchel, I found a pretty nifty product on the Hilti website - a fire-rated conduit foam plug that can be cut and/or penetrated by cables. But I bet rock wool/Roxul will be a heckuva lot cheaper.
 
OK, I have my answers - I emailed specific Q's yesterday to the inspector, he called me this AM.

The walls of the chase are not fire rated, and don't need to be, for a residence. Therefore, any access panel will be adequate, to avoid drywall work in my wife's closet.

Any Carlon conduit will suffice - Resi Gard, Riser Gard, Blue ENT/Smurf tube.

Drywall X (fire rated to 1 hour) is only required in the garage.

The next 3-4 weeks is very busy for me, with traveling for work and vacation, and wife traveling, so it will be a while before I post some pics. But this is at the top of my list! Soon to follow - replacing my alarm with an M1, adding water sensors, and DA. Wife is going to love the multitude of drywall holes, and the $$$. :icon_pai:
 
I don't live in the city, so I have to meet generic IBC codes. I put a plastic 2" conduit basement to attic in my fireplace chase and the inspector nixed it. I ended up with a 2" steel conduit.
Fireblocking is supposed to be non-combustible. Make sure you firecaulk all your penetrations.
 
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