expanding foam

Brad White

require a 2-inch clearance between a masonry chimney and combustible construction. Argue as I might, as you did, that the temperatures never approach a fraction that of charring let alone ignition.

I also once argued the chimney effect and how a basement fire could be conducted to the attic.... no dice.

The foam pressure will not warp the brick- Sheesh, if it did that, I would use foam to push my car out of a snowbank. Wait, did I say snow?

Jim_109

Expanind Foam

Any comments on using expanding foam to seal any drafts where the chimney meets the floor and ceiling? My chimney is located in the center of my 85 year old home. I am considering spraying the foam around the chimney where it penetrates my basement floor and ceiling on the second floor.

According to the manufacturer, 240 is the maximum temp for the foam. I doubt it gets that hot on the outside of the bricks.

Though the chimney is in good shape, I am concerned about damaging the bricks and morter from the foam pressure.

scrook_2

fire stop foam?

Might you use fire stop foam, as used in commercial construction to seal floor penetrations, etc?

Ken_40

I suspect

the code is not an issue. This is NOT new construction. I'd foam it. This assumes you have a clay liner in good shape, as well as a good chimney that the flue liner passes thru.

If either is suspect, I'd opt for fireproof foam-like substance or, jam fiberglass in the void(s).

EBEBRATT-Ed

Don't know about using foam. In the old days you wold nail some blocking and then use mortar.
I have been told that fiberglass is ok.


ED

Kevin O. Pulver

> require a 2-inch clearance between a masonry

> chimney and combustible construction. Argue as I

> might, as you did, that the temperatures never

> approach a fraction that of charring let alone

> ignition.

>

> I also once argued the chimney

> effect and how a basement fire could be conducted

> to the attic.... no dice.

>

> The foam pressure

> will not warp the brick- Sheesh, if it did that,

> I would use foam to push my car out of a

> snowbank. Wait, did I say snow?



I've lived in enough third world countries that I can appreciate some good ol' building code.
But sometimes, you gotta do the common sense thing.
One hundred pound hydrostatic test is the standard for radiant tubing around here. I blew it off on a commercial job I did. My reasoning: If it will hold 60 pounds of air, it will hold 12 pounds of water. And I don't have control over when the building is enclosed and I can install and fire the boiler. It might be sub-zero before then. Strangely enough, the inspector agreed. Kevin

Ken Field

Foam is not allowed by fire code although I agree that there is very little chance of it catching fire. Fiberglass won't stop air movement unless you put it in a plastic bag and stuff the whole thing in the crack.

Ken

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Uni R_3

Rock wool?

Seems ideal...

[Deleted User]

Old code...

I once lived in a house that had brick chimneys and an airtight wood burning stove. One night, the chimney caught on fire, and the bricks WERE glowing red, and I am GLAD there was a gap in the masonry surrounding the chimney, or my house might have very well burnt to the ground.

If you do not have any solid fuel fired appliances and don't have any chance of having a fire in your flue, then I'd say you're probably safe in using the foam.

ME

joel_19

fire stop

You cannot use foam but they make afire stop material that will work

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[Deleted User]

Intumescent caulk

http://www.jmfirestopping.com/jm/listings/FiretempCIdataSheets.pdf

Swells with fire...

ME