Thread: Fire blocking around boiler vent

House was built in 07, single family. The vents pass through the ceiling, there is fire blocking around the OSB but not the drywall. Attic space is located above, and fire blocking is present around the penetration into the attic. Is it required around the drywall. Boilers were 1.2 million to 1.9 million BTU, could not determine vent type.

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Originally Posted by mathew stouffer

House was built in 07, single family. The vents pass through the ceiling, there is fire blocking around the OSB but not the drywall. Attic space is located above, and fire blocking is present around the penetration into the attic. Is it required around the drywall. Boilers were 1.2 million to 1.9 million BTU, could not determine vent type.

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see page 3 of attachment.
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FasNSealW2 venting: you would need to ascertain the max. stack temp. If no greater than 400F, the pipe carries a 1" clearance to combustibles in a vertical application. If the stack temp. is btw 400-480F. the clearance for this diameter jumps to 6". Drywall and OSB are considered combustibles. I do not see the listed firestop. Fireblocking surrounds a listed firestop. Placing combustibles over a listed firestop or fireblocking defeats the whole purpose of it.

The failed to use a listed single walled pipe adapter. Instead, it appears they nuked it with silver silicone. That single walled welded stainless steel connector would need to be listed as well for CAT III or IV appliances.

Where it penetrates into the attic, you need at the very least an attic insulation shield. If your code requires 'vertical fireblocking', then you can skip the attic shield if you box it in with stated clearances and run vertical fireblocking all the way to the underside of the roof deck following 602.8

HTH,
Bob

That is a big boiler. Big condo unit, or just a super sized house?

Matt,
Ceiling firestops are required for that penetration and are availible. I think these boilers are modulating perhaps and are 102,000 - 109,000 btu/hr. If they were in the millions the stack would be much larger than 5 inch.

Thanks for the pictures

Jack

Jack, the boilers are 1.2 1.5 and 1.99 MILLION.

Bob, You are correct about the clearnaces, but I could not obtain the max temp, so I went with 400 degrees. Also, does an adapter need to be installed inplace of the silver silicon.

Matt, I have to agree with Jack that there is something wrong with your BTU count. Or you aren't giving us enough info.
You are talking about almost 4 million BTU combined. That is not house BTU, That is large apartment building BTU.
From the pics, it looks like 1.5" coming out of the boiler going to 2". If I am seeing the sizes right, that doesn't quite make sense. You might have 1.5" to 2" on the smaller ones but 2" would be much more common. 2" out up to a 3" main line would be more common on the 1.99 unit.
For those size units, around here at least, I would want to see at least a 2" main pump and smaller jockey pumps on the zones. The flue size also doesn't make sense for those BTU sizes.
How big is this place, are the multiple zones?
If you are right on the BTU, I would strongly recommend the client have an independent boiler inspection. This just doesn't sound right. There's got to be more to this situation.

All I can tell you is what was written on the side of th boilers. There were 3 boilers, each with its own vent. This is a home 7,500 feet. One boiler is for the driveway snow melt, one for the deck snow melt and one for a pool.

Ah, well now it makes sense. Those boilers aren't for heating the house. Was a glycol charging sheet/label present for the driveway and deck systems? Around here such systems have a glycol mix, not straight water. It is important to know what is in the system for repair and contamination purposes. Consider putting a line item recommendation in the report about it.

Originally Posted by Bob Harper

FasNSealW2 venting: you would need to ascertain the max. stack temp. If no greater than 400F, the pipe carries a 1" clearance to combustibles in a vertical application. If the stack temp. is btw 400-480F. the clearance for this diameter jumps to 6". Drywall and OSB are considered combustibles. I do not see the listed firestop. Fireblocking surrounds a listed firestop. Placing combustibles over a listed firestop or fireblocking defeats the whole purpose of it.

The(y) failed to use a listed single walled pipe adapter. Instead, it appears they nuked it with silver silicone. That single walled welded stainless steel connector would need to be listed as well for CAT III or IV appliances.

Where it penetrates into the attic, you need at the very least an attic insulation shield. If your code requires 'vertical fireblocking', then you can skip the attic shield if you box it in with stated clearances and run vertical fireblocking all the way to the underside of the roof deck following 602.8

HTH,
Bob

Originally Posted by mathew stouffer

Bob, You are correct about the clearnaces, but I could not obtain the max temp, so I went with 400 degrees. Also, does an adapter need to be installed inplace of the silver silicon.

Bob H. Addressed your question before you asked it: see above.

Markus, typically they will try a 60 40 glycol to water when possible, but this place was around 8700 feet so they may have increased the mix, not sure.