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kiln construction (rain-proofing the chimney)

updated tue 27 may 03

 

David Hendley on thu 22 may 03


A few days ago Russell asked about keeping rain out of his chimney and away
from the kiln where the stack passes through the roof.
As for rain coming down the chimney, the best solution is a kiln shelf or
piece of
flat steel, and a ladder. Climb onto the roof of your kiln shed and cover
the top of the
chimney when your firing is finished. If the chimney is too tall, build a
short
ladder that can stay up on the roof to reach.
This has the added advantage of sealing the kiln for a good slow cooling.

You need flashing around your chimney to keep the rain out where the chimney
passes through the roof. Same as a fireplace chimney on your house.
Make, or have a sheet metal shop make, a "skirt" that will be installed on
the
culvert. This will keep water out on the sides and downward side of the
roof.
On the upward side of the roof, you need either a flashing made to fit with
your
roofing tin, or you need to just let the water drip down, and install a
short section
of gutter that will direct the water to the side of the kiln. You will
probably want
to let the sheet metal shop make the flashing if you decide to go that
route.

David Hendley
Maydelle, Texas
david@farmpots.com
http://www.farmpots.com



----- Original Message -----
Hello all,
I was hoping someone could offer some advice as I consider modifying my
kiln's chimney. My chimney is a piece of culvert pipe sitting atop my brick
flue box. It is secured by two all-thread bars which wrap around the pipe
and are bolted to a railroad tie which stands nearby. A metal roof covers
the outside kiln, which has a hole in it to allow the chimney to rise
through.
My two questions are. What could I use to shield rain from sneaking between
the small space between the roof and chimney and getting to my bricks?
What could I install at the top of the chimney to keep rain out, without
affecting the current flow of draft.
Russell Adams
Black Dog Pottery
573.698.3318
http://blackdogpottery.us

Jennifer F Boyer on mon 26 may 03


As I remember, the original person sending the question about
flashing was using a culvert for a chimney. I have one of those,
and fitting a commercially sold flashing kit to the culvert is
not easy. The culvert I have is corrugated. We just wrapped the
flashing around the culvert as tightly as possible and then
caulked the daylights out of the spaces.

As to protecting the inside of the chimney from rain, I have to
admit(!) that I've left my chimneys of my gas kiln(rebuilt 3
times during moves) totally exposed for 28 years! Snow kinda
piles up in on the damper, but it melts quickly when I turn the
gas burners on.

My chimneys have been:
a 1/4" thick steel pipe(10 years), one of those insulated
stainless steel jobbies(14 years), and a culvert lined with 1"
fiberfax to within 16 inches of the top(4 years). None of them
has showed much damage from being exposed. The inside of the
culvert is a bit rusted, but the ladder thing just doesn't
appeal to me!

I think if it started really getting eaten away by rust at the
top, I'd get the local sheet metal shop to make me a sleeve to
put around the top rim.

Just putting a plug for the head-in-the-sand approach!

Take Care
Jennifer

David Hendley wrote:
> A few days ago Russell asked about keeping rain out of his chimney and away
> from the kiln where the stack passes through the roof.
> As for rain coming down the chimney, the best solution is a kiln shelf or
> piece of
> flat steel, and a ladder. Climb onto the roof of your kiln shed and cover
> the top of the
> chimney when your firing is finished. If the chimney is too tall, build a
> short
> ladder that can stay up on the roof to reach.
> This has the added advantage of sealing the kiln for a good slow cooling.
>
> You need flashing around your chimney to keep the rain out
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Jennifer Boyer mailto:jboyer@adelphia.net
Thistle Hill Pottery Montpelier VT USA
http://www.thistlehillpottery.com/

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