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Renovator8....Q for you...and anyone else

Posted by AnnieDeighnaugh (My Page) on
Tue, Jul 10, 12 at 20:19

You seem to know something about chimneys. We have two plywood chimneys which we've coated with thin stone. Because it is a combustible interior, code says the chimney outlet needs to be at least 2' above combustilbe materials, which has left us with ugly metal chimney tops. Do you know of a solution or where to get terra cotta chimney pots that might cover the metal and not violate code?


Follow-Up Postings:

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RE: Renovator8....Q for you...and anyone else

I assume these are two gas appliance B-vent terminations that stick out of two structures that are intended to look like masonry chimneys. The roof clearances required for masonry or factory-built wood-burning fireplace chimneys would not apply to simulated chimneys or B-vents.

12" and smaller B-vent caps are normally allowed to terminate 1 ft. above a flat roof and 4 ft above a 12/12 pitch roof. This is for proper drafting rather than fire protection. Clearance to combustibles for such a vent is 1 inch minimum.


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RE: Renovator8....Q for you...and anyone else

The standard developer solution is sold as a unit by many companies:

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The height of the simulated chimney at the high side is usually 4 ft so it can sit on a roof slope up to 12 in 12. It must be at least 8 ft from a vertical wall. There are alternate vent caps available and the cap can be covered with what looks like a traditional chimney spark arrestor but if you paint the cap medium blue-grey or red-brown it will not be noticed.


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RE: Renovator8....Q for you...and anyone else

The near one on the front of the house is a gas fireplace.

The far one on the back of the house is a wood stove.

We were told by the woodstove co. that only a certain vent can be used and this was it.

The chimney surround is plywood that was put in by our framers and we had masons cover it with the same thin stone that was used on our front gables. They are not kits made to look like chimneys. I can't see putting a fake brick surround on top of our stone chimneys, especially when there is no brick on our exterior any where.

Here are close up shots of the chimneys

I'm wondering if there is something like a clay pot that can be wrapped around or slid over the metal pipe to cover it....


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RE: Renovator8....Q for you...and anyone else

If the gas fireplace has a glass front, the "direct vent" will be double-walled for intake and exhaust and is known as a type B vent. This is what is shown in the simulated chimney photo (the cladding can be brick, stone or stucco) and it is essentially what you already have except the vent extends far above the enclosure for reasons best known to the builder/designer. This is a gas vent, not a chimney and must meet the requirements of the fuel-gas code instead of the requirements for a factory-built chimney in the building code.

The wood-burning stove will have a factory-built chimney that must meet the requirements of the building code and the manufacturer's installation instructions. Decorative shrouds installed at the termination of a factory-built chimney must be listed and labeled for use with the specific factory-built chimney system.

There are companies that make properly listed shrouds and chimney pots (see link).

Here is a link that might be useful: copper chimney pots


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RE: Renovator8....Q for you...and anyone else

OK...I think I understand. I'll have to investigate further. We had one guy tell us there was no need to put the vent so high, but the chimney installer insisted....he may have just been wrong though.

Those chimney pots are lovely, though $$$!

Thanks for your help....most appreciated!


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RE: Renovator8....Q for you...and anyone else

perhaps , you could have your roofer , or sheet metal man , fabricate chimney covers of the same media as the flashing above the front entry ...

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RE: Renovator8....Q for you...and anyone else

Wow! You really captured my house!


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RE: Renovator8....Q for you...and anyone else

I realize how tempting it is to think of a metal chimney serving a wood-burning stove as if it were a masonry chimney but it is a "factory-built chimney". Building codes do not tell you how to design, build and install such systems because there are just too many of them. Instead, the code requires these systems to be tested and approved by Underwriters Laboratories (UL) (or other testing agencies) and requires the installer to follow the manufacturer's installation instructions. If a "decorative shroud" is installed at the chimney termination it must be tested and approved by UL Laboratories for the specific chimney system and installed according to the manufacturer's instructions.

So, instead of building an on-site shroud or "chimney pot" you must buy one from a manufacturer that has paid UL to test it. That is one of the reasons chimney pots for factory-built chimneys are so expensive.

Gas vents are covered by the fuel-gas code.


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also

If the existing UL rated chimney terminations are above the tapered decorative enclosures in Summerfield's design and the enclosures are not combustible or part of the chimney flashing system, they might be allowed.

I doubt they would be much cheaper or better looking than a factory built shroud.


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RE: Renovator8....Q for you...and anyone else

You can also find new/vintage terra cotta pots online or local (depending where you live). Most brick places carry several lines you can purchase. Our local brick place carries the Jack Arnold copper ones shown above. When we were building, they were just approved/made to work on masonry FP. Now they are used on either masonry or prefab.

Our HVAC company made our copper chimney cap. I can't find the picture of them unloading the day it arrived, but it's huge - large than a bathtub. The copper has already turned in this picture. They can make it any shape you want. Our chimney was clad in copper by them as well. Also the curved copper roofs on the three dormers.

I wanted copper as our house was designed by Jack Arnold and has a copper cupola on the stone garage (barn). We also used copper gutters and flashing, and there are copper accents inside the house as well.


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RE: Renovator8....Q for you...and anyone else

According to dh, supposedly they made copper caps for the chimney as it is, but when it rains heavily, we can hear the rain hitting inside somewhere in both the gas fireplace and the wood stove, so I suspect it may have to do with spacing at the top that is allowed for expansion when the chimney gets heated. But having never been up there to see what was done, I actually have no idea. But I'm suspecting some kind of cap would improve the rain situation.


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RE: Renovator8....Q for you...and anyone else

If you have leaks you should get a roofer up there ASAP.


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