Thread: Stone Chimney cap

Is there a clearance requirement for chimney caps?

Also, is this even allowed? I would think that a cap would have to be listed.

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What's under the siding? Is that an old masonry flue/chimney assembly with a stone crown that someone covered up, or a pre-fab, "listed" flue assembly?

Dom.

It is a block chimney that has siding covering it.

Some of the older portion of the house has stone which may have been the original chimney covering.

Since the chimney itself isn't listed there is no requirement that the cap be listed. This cap, though, is so low over the flue it is likely to cause smoking/performance problems. Currently, NFPA 211 requires the underside of the cap to be a distance above the flue equal or greater than the lesser dimension of the flue. i.e 8 x 12 flue the cap lid would have to be 8 inches above flue. That requirement is new in the 2010 edition of NFPA 211 and prior to that there was no requirement for minimum height. 6 to 8 inches was a pretty widely accepted rule of thumb for minimum height above flue. In your picture it looks to be about 4 inches.

The cap doesn't bother me. I've seen nice versions of that on may houses. My concern would be what's under the vinyl. Did they put the vinyl up because it was cheaper than having a bricky relay and point a very eroded chimney? What about roof to chimney flashing.
I hope your report warns about potential problems under the vinyl, possible leaks and hidden factors.

Did the ridge board have to be cut to accomodate the chimney?

And putting vinyl siding over stone? What would induce someone to do that? Don't tell me they just like the look of vinyl.

No 2" clearance to combustible siding. You don't wrap masonry chimneys with plastic siding.

If NFPA 211 is an adopted code in your jurisdiction, you can refer to it as mandatory compliance. Otherwise, it remains a good reference or yardstick. The IRC does not address cap clearances.

The bottom line is, it must be functional. It also must be "accessible" for service and inspection, which these will not meet so that is grounds enough to flag them.

Originally Posted by Bob Harper

No 2" clearance to combustible siding. You don't wrap masonry chimneys with plastic siding.

If NFPA 211 is an adopted code in your jurisdiction, you can refer to it as mandatory compliance. Otherwise, it remains a good reference or yardstick. The IRC does not address cap clearances.

The bottom line is, it must be functional. It also must be "accessible" for service and inspection, which these will not meet so that is grounds enough to flag them.

Bob,

Also, isn't the flue tile supposed to be a minimum height above the chimney cap? Something like 2" minimum?

Jon,

Looks like the original facing for the chimney was removed and the vinyl siding installed, and the rough part of the concrete chimney cap is what sagged down between the original facing and the masonry chimney.

Hopefully, a simple question.
Inspection yesterday...the "new": home had two prefabricated "zero" clearance gas fireplaces with sealed doors. One had a decorative marble hearth and the other had carpet directly in front with no hearth. Is there a requirement for a non combustible area in front of these types of units????

Originally Posted by Jeff Zehnder

...carpet directly in front with no hearth. Is there a requirement for a non combustible area in front of these types of units????

All of the manufactures installation instructions for the gas, zero clearance units (this is what they call them) installed in this area do not require any clearance for floor coverings.

FMI fireplaces are the most used....and I can't think of the other manufacturer right now.

Please, for the love of God, erase that term "zero clearance" from your vocabulary. It has gotten more people into trouble than you can imagine. They are "factory built fireplaces" and "gas hearth appliances" for wood and gas respectively.

All woodburners require some level of spark guard floor protection and usually a very specific thermal insulative protection. Gas Fps are tested basicially the same way but if the floor temps do not exceed 117F above ambient, they do not require floor protection. Those that entrain convective air usually pull a blanket of cooling air in across the floor cooling it. Radiant clean faced units would be more prone to needing floor protection. As with all factory built fireplaces, the need or exemption for floor protection can be found in the listed instructions.

It is good to learn the units more prevalent in your area but you must be prepared to inspect any and all brands and models. That's another reason to take Dale Feb's FIRE courses.

HTH,