Fireblocking & Draftstopping - HE Pipes At Chase

[dtontarski]

I'm looking for information on what would be a standard and approved method/material for fireblocking & draftstopping at the point the pipes for a high efficiency direct vent furnace enter the base of a wall chase on route to a through the roof install. Any information would be appreciated. This looks like it would be pain to install metal flashing around. Would ceramic wool be an option?

Thanks!

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[Jim Katen]

Around here, tightly packed fiberglass is considered acceptable.

[Bill Kibbel]

I have a list of approved materials.

Fireblocking:

• Fiberglass or mineral wool insulation
• 1/2" drywall
• 1/4" cement millboard
• 2x lumber
• 1x lumber, if 2 layers
• 3/4 plywood, OSB and particleboard.

Draftstopping:

• 1/2" drywall
• 3/8" plywood or OSB

[RickSab]

Wouldn't a fire rated expandable foam work. Great stuff and others make fire block spray.

[Jim Katen]

Wouldn't a fire rated expandable foam work. Great stuff and others make fire block spray.

Last time I looked at a can of that stuff, it specifically mentioned that it was intended to be used to fill small gaps, not large openings.

[Mike Lamb]

Wouldn't a fire rated expandable foam work. Great stuff and others make fire block spray.

Last time I looked at a can of that stuff, it specifically mentioned that it was intended to be used to fill small gaps, not large openings.

I see the orange foam often and never thought about fill limitations so I did some Googling.

From Dow on Great Stuff Fireblock:

Fills, seals and insulates gaps up to 1/2 inch

http://building.dow.com/na/en/products/ ... eblock.htm

According to the ICC which looks like it lumped all Great Stuff products into one:

A) Max. 1 5/16" wide, 3" thick max. B) max. 34 sq. in. per sq. ft.

http://www.icc-es.org/reports/pdf_files ... R-1961.pdf

[Jim Katen]

For single family homes, it's just not a big deal. Stuff the opening with whatever. But I wouldn't trust the orange foam on any critical application.

If it's multifamily, where a fire could spread to several floors and across many units, I expect to see clean openings and fire caulk and some kind of intumescent seal at plastic penetrations.

[Hearthman]

As long as it is not fire rated construction and that chase is less than 4 stories, you can use the list of materials in the IRC R302.11, or approved materials, which is essentially the list Bill provided. Now, let's say you want to use a material not on that list such as sheetmetal or foam. Go to your AHJ and get it approved. The main thing is, it must provide an effective fire barrier between separations. If you are not dealing with rated fire walls or shafts, then this std. applies.