Thread: chimney cap / cricket

stucco frame chimney with an A vent metal flue. I noticed that the chimney cap (copper) was the only thing between the attic and outside. I t seems that all the others i have seen have had plywood, water proofing/vapor barrier stocco etc. This just had the matal cap? Problem?

Noted also the chimney was 30" or so and had no cricket, however the chimney penetrated the roof only about 3 feet below the ridge between two hips. Is there enough room for a cricket?

Noted also that this flue requires 2" clearance to combustables. Is loose fill fiberglass ok?

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Originally Posted by Jerome W. Young

stucco frame chimney with an A vent metal flue.

You mean B vent?

This just had the matal cap? Problem?

Just the copper-to-galvanized contact (dissimilar metals contact).

Noted also the chimney was 30" or so

How close was the "or so"?

and had no cricket, however the chimney penetrated the roof only about 3 feet below the ridge between two hips. Is there enough room for a cricket?

Yes.

Noted also that this flue requires 2" clearance to combustables. Is loose fill fiberglass ok?

Nope. Needs to have an insulation collar around it to keep the insulation back that 2".

It might be better to refer to this as a copper chase flashing than a cap. Most people think of the cap as the vent termination. The mfr. specifies how a chase can be flashed and if it must be ventilated or not. Yes, you must protect against dissemilar metals. This vent appears to be crooked near the top. There is no visible support in either pic. There must be a listed firestop and fireblocking per the codes and listing. If you find plywood under the chase flashing, it must be cut out to meet clearances. If you have combustible membranes on top of the chase, you're looking to burn the house down.
Stated clearances are air spaces. The unit is covered with two types of insulation which must be removed. What is that framing cut out? The elbow strap does not appear installed. If the vent penetrates and insulated space, there must be an attic insulation shield.

So, how did you get into the chase to get these pics?

Bob Harper

Originally Posted by Bob Harper

There is no visible support in either pic.

Oops, I missed that.

There must be a listed firestop and fireblocking per the codes and listing.

So, how did you get into the chase to get these pics?

Bob,

I think I can answer that (not that Jerome cannot answer for himself, though): Jerome was in the attic looking up into the chimney chase from the attic, no fireblocking is required at the roof sheathing, only down below at the ceiling.

Jerome,

Something else I noticed when I went back to look at it after Bob's post ... you have that tall chimney chase framed out and resting there on top of the roof sheathing ... but what is holding it down and holding it from tipping over?

From what I see, it is not going to take a real big wind to blow that thing over, if not completely off the roof.

I'm used to seeing the studs go all the way down to the truss bottom chords for lateral support and uplift resistance, or, at the very least, every stud there strapped down to the trusses and additional blocking. I now you don't get many hurricanes there at Vero Beach, but I was next door to there in Ft. Pierce in 1965 when (I think it was 1965) two hurricanes came though, and then there were two more in 2004 which hit Stuart and Ft. Pierce - I'm sure you guys felt it too, you are only maybe 20 miles north of Ft. Pierce.

more pics. They used roofing cement at the cap area to stop some leaking. My biggest concern was the top of the chimney and that there was no covering except for the copper cap. The was a fire stop at the ceiling and 2" seperation, but I will make a note about the loose fill insulation. I did not measure the chimeny Jerry unfortunately.

This chimney made it through the 04 storms but i will mention the strapping. "Jerry, I actually live in Ft. Pierce"

A standard 3 tab shingle is12"x36". It looks like that you just might have 3 full tabs at the point the chimney and roof meet. Current code indicates chimneys 36 or greater require a cricket. Had they extended the ridge line all the way over to the chimeny, it would have acted as a cricket.

That is an unlisted vent termination which is a fire hazard and should be removed. You need to identify the make, model and serial number of this fireplace and venting. Get the listed instructions, then install to those instructions and the building code.

The IRC, section R1003.20 calls for crickets when the chimney is >30 inches, which they reference as parallel to the ridgeline. While this is hip, since it is greater than 30", it should have a cricket. Due to the proximity to the ridge, extending the ridge would have addressed it properly. Even thought R1003 pertains to masonry chimneys, most AHJs will apply it to chases as well. R905.2.8.3 does pick it up under roof assemblies but they still refer to it as a "chimney".

I suggest you recommend a Certified Fireplace Inspector perform a Level II inspection of this unit ASAP. Click on the Fire Service button to locate the one nearest you.

HTH,
Bob

Originally Posted by Jerome W. Young

"Jerry, I actually live in Ft. Pierce"

Jerome,

Where at?

I graduated from Dan Mc Carty High School (which is now a middle school... I think) and went to the Junior High School next door (which is now an elementary school ... I think), and, attended a year or two at Delaware Elementary School on Delaware Ave.

My Dad did a lot of the electrical work at Sand Spur Tech when it was built (also known as Indian River Junior College, except back then there was no grass, just sand spurs all over, hence the nick name).

Jerome,

Based on the photo, I'm guessing that is about 42" wide, possibly as little as 36" (but I think it is closer to 42").

Originally Posted by Bruce Ramsey

A standard 3 tab shingle is12"x36".

Originally Posted by Jerry Peck

Jerome,

Based on the photo, I'm guessing that is about 42" wide, possibly as little as 36" (but I think it is closer to 42").

I'd put it closer to 48" and looks like water pools until evaporation or leakage.

My eye's must be getting bad. That sure looks like a galvanize cap to me. Instead of tar they should of used some C-4.
That will fix it.

Mike,

C-4? As in plastique?

BOOM!

Bob,
could you elaborate alittle on why that cap is a problem.

That squirrel cage is for brick chimney flue's.
The stove pipe is open on the top and I could be wrong but the proper termination cap for it may prevent down drafting and such.