The three-foot tall, four-feet long sheet steel fabricated around my
chimney is falling apart so I took it down.

All that is sticking up out of the chimney itself are the elaborate spark
arrestors (multiple chimneys use the same concrete column) which look
like 18" tall space ships sticking out of the top of the chimney.

I realize the cap I removed served an aesthetic purpose; but is that the
ONLY purpose?

That is, with the spark arresters (or whatever they are) sticking out of
the chimney still intact, what 'function' does the three-foot wide by
four feet by two feet painted steel chimney 'surround' cap perform?

A secondary question would be advice for fabricating a new one if it's
needed (it certainly would look better with it back on).

On Apr 6, 4:36*pm, Aaron FIsher wrote:
The three-foot tall, four-feet long sheet steel fabricated around my
chimney is falling apart so I took it down.

All that is sticking up out of the chimney itself are the elaborate spark
arrestors (multiple chimneys use the same concrete column) which look
like 18" tall space ships sticking out of the top of the chimney.

I realize the cap I removed served an aesthetic purpose; but is that the
ONLY purpose?

That is, with the spark arresters (or whatever they are) sticking out of
the chimney still intact, what 'function' does the three-foot wide by
four feet by two feet painted steel chimney 'surround' cap perform?

A secondary question would be advice for fabricating a new one if it's
needed (it certainly would look better with it back on).

Take your specs to a good sheet metal shop and have them build you
one. There are nice coated sheet metal types available today that are
perfect for painting. If you get one made with these modified
galvanized materials it should last for many years.

Joe

On Apr 6, 4:36*pm, Aaron FIsher wrote:
The three-foot tall, four-feet long sheet steel fabricated around my
chimney is falling apart so I took it down.

All that is sticking up out of the chimney itself are the elaborate spark
arrestors (multiple chimneys use the same concrete column) which look
like 18" tall space ships sticking out of the top of the chimney.

I realize the cap I removed served an aesthetic purpose; but is that the
ONLY purpose?

That is, with the spark arresters (or whatever they are) sticking out of
the chimney still intact, what 'function' does the three-foot wide by
four feet by two feet painted steel chimney 'surround' cap perform?

A secondary question would be advice for fabricating a new one if it's
needed (it certainly would look better with it back on).

Post a photo, its there for keeping smoke away by being high. your
setup seems humerous, or dumb.

"Aaron FIsher" wrote in message
...
The three-foot tall, four-feet long sheet steel fabricated around my
chimney is falling apart so I took it down.

All that is sticking up out of the chimney itself are the elaborate spark
arrestors (multiple chimneys use the same concrete column) which look
like 18" tall space ships sticking out of the top of the chimney.

I realize the cap I removed served an aesthetic purpose; but is that the
ONLY purpose?

That is, with the spark arresters (or whatever they are) sticking out of
the chimney still intact, what 'function' does the three-foot wide by
four feet by two feet painted steel chimney 'surround' cap perform?

A secondary question would be advice for fabricating a new one if it's
needed (it certainly would look better with it back on).

It may be functional and required by code. The chimney must extend some
distance higher than anything with in some distance of the chimney.

I forget the exact figures, but it is easy enough to Google.

Any metal fabrication shop can make one for you Consider stainless steel so
it last a long time.

On Wed, 06 Apr 2011 15:44:07 -0700, Joe wrote:
If you get one made with these modified galvanized
materials it should last for many years.

The old one was (apparently) galvanized sheet metal because I don't see
any rust but it was very heavy lifting off the chimney (which sticks up
off the roof by at least four feet).

The problem is high wind. We get 100mph winds here on the mountain facing
the ocean. Over time, the winds caved in the structure.

I'll take a measurement and post that later. I think it needs better
cross bracing against the wind.

But, what I'm trying to find out is whether it's actually necessary. It's
going to rain tomorrow but when it's dry, I'll try to go up and snap a
picture or three to post so you can see what I'm talking about.

Thanks.

On Wed, 06 Apr 2011 15:58:36 -0700, ransley wrote:

Post a photo, its there for keeping smoke away by being high. your
setup seems humerous, or dumb.

I'm not sure what's humorous about the setup but when the rain abates,
I'll post a photo so you can see what it looks like (or maybe I'll use a
zoom lens from the ground to snap a picture for you).

The chimney, which is thirty feet above the ground and about five feet
above the roofline should keep the smoke nice and high, shouldn't it?

Besides, the top of the enclosure is just a tad higher than the top of
the spark arresters so I don't see how this enclosure does ANYTHING about
smoke.

I'm confused. Can someone explain how the enclosure handles smoke?

On Wed, 06 Apr 2011 22:50:10 -0400, Ed Pawlowski wrote:

It may be functional and required by code.

That's what I'm trying to figure out!

The chimney must extend some distance higher than anything
with in some distance of the chimney.

The chimney is a good five feet above the roofline and the sheet metal
enclosure is another 2 1/2 to 3 feet above that (which is just about as
high as the spark arresters).

Plus it's a clay tile roof so there's not much nearby to catch on fire.

Any metal fabrication shop can make one for you Consider stainless
steel so it last a long time.

The one I have seems to be galvanized (no rust) but the wind, which gets
to 100mph across the ocean, is what knocked it over. So, whatever I use
must be able to withstand moderately high winds all winter.

On Thu, 7 Apr 2011 04:40:52 +0000 (UTC), Aaron FIsher
wrote:

On Wed, 06 Apr 2011 15:44:07 -0700, Joe wrote:
If you get one made with these modified galvanized
materials it should last for many years.

The old one was (apparently) galvanized sheet metal because I don't see
any rust but it was very heavy lifting off the chimney (which sticks up
off the roof by at least four feet).

The problem is high wind. We get 100mph winds here on the mountain facing
the ocean. Over time, the winds caved in the structure.

I'll take a measurement and post that later. I think it needs better
cross bracing against the wind.

Of course that will make it a little heavier. REading all your posts,
I'm amazed you got it down.

But, what I'm trying to find out is whether it's actually necessary. It's
going to rain tomorrow but when it's dry, I'll try to go up and snap a
picture or three to post so you can see what I'm talking about.

Thanks.

You don't say what you burn that needs a chimney, or what the chimneys
are made of.

AFAIK the purpose of a chimney cap is to keep critters and rain out.
Even the low sulfer oil that I burn in my furnace has some sulfer and
soot inside the chimney can turn to sulfuric acid when it mixes with
water. I think it still takes a long time to eat through a stainless
steel chimney. Are their other combinations that might cause
problems, I don't know. Maybe if it rains hard enough it can put out
the fire...pretty much kidding. I doubt that.

As to critters, that includes squirrels, birds, raccoons?, and
pterodactyls.

"Aaron FIsher" wrote in message
...
On Wed, 06 Apr 2011 22:50:10 -0400, Ed Pawlowski wrote:

It may be functional and required by code.

That's what I'm trying to figure out!

The chimney must extend some distance higher than anything
with in some distance of the chimney.

The chimney is a good five feet above the roofline and the sheet metal
enclosure is another 2 1/2 to 3 feet above that (which is just about as
high as the spark arresters).

Plus it's a clay tile roof so there's not much nearby to catch on fire.

That should be OK. Three feet above the roof where it comes out Two feet
above anything within 10 feet.

"Ed Pawlowski" wrote in message
...

"Aaron FIsher" wrote in message
...
On Wed, 06 Apr 2011 22:50:10 -0400, Ed Pawlowski wrote:

It may be functional and required by code.

That's what I'm trying to figure out!

The chimney must extend some distance higher than anything
with in some distance of the chimney.

The chimney is a good five feet above the roofline and the sheet metal
enclosure is another 2 1/2 to 3 feet above that (which is just about as
high as the spark arresters).

Plus it's a clay tile roof so there's not much nearby to catch on fire.

That should be OK. Three feet above the roof where it comes out Two feet
above anything within 10 feet.

I hate that word SHOULD. The OP's statement sounds like the chimney is high
enough. But it could also be higher than necessary, inviting problems.
Check with local codes. Usenet is a good thing, but it's like asking the
weather tomorrow. I can say what it's going to be HERE, but everyone
doesn't live HERE. So, start at the local level, find out the facts, and
then build to comply.

When dealing with height, any increase increases the leverage put on it by
wind.

Steve

Heart surgery pending?
www.cabgbypasssurgery.com

On Apr 7, 7:24*am, "Steve B" wrote:
"Ed Pawlowski" wrote in message

...







"Aaron FIsher" wrote in message
...
On Wed, 06 Apr 2011 22:50:10 -0400, Ed Pawlowski wrote:

It may be functional and required by code.

That's what I'm trying to figure out!

The chimney must extend some distance higher than anything
with in some distance of the chimney.

The chimney is a good five feet above the roofline and the sheet metal
enclosure is another 2 1/2 to 3 feet above that (which is just about as
high as the spark arresters).

Plus it's a clay tile roof so there's not much nearby to catch on fire..

That should be OK. *Three feet above the roof where it comes out Two feet
above anything within 10 feet.

I hate that word SHOULD. *The OP's statement sounds like the chimney is high
enough. *But it could also be higher than necessary, inviting problems.
Check with local codes. *Usenet is a good thing, but it's like asking the
weather tomorrow. *I can say what it's going to be HERE, but everyone
doesn't live HERE. *So, start at the local level, find out the facts, and
then build to comply.

When dealing with height, any increase *increases the leverage put on it by
wind.

Steve

Heart surgery pending?www.cabgbypasssurgery.com- Hide quoted text -

- Show quoted text -

I sounds like the chimney surround is higher than the individual
chiumney stacks from the individual units. A photo of that's on the
roof now, and a photo of what was removed would sure help!!!!

On 2011-04-07, mm wrote:

As to critters, that includes squirrels, birds, raccoons?, and
pterodactyls.

I'd be more concerned about the flammability of the critters' nests than
the critters themselves.

"ShadowTek" wrote in message
n...
On 2011-04-07, mm wrote:

As to critters, that includes squirrels, birds, raccoons?, and
pterodactyls.

I'd be more concerned about the flammability of the critters' nests than
the critters themselves.

Well, actually, if the chimney is not used long enough for them to build
that big a nest, what happens is that when you start the first fire of the
season, it gets scary from there. If the nest is small enough, it is all
incinerated. That would be in the fall after the young birds had fledged,
so there would be no KFC extra crispy. If the nest is big enough to block
the airflow, it's an "OH ****" moment. If the bird is a mud nester, it may
not burn off at all, causing a partial or full blockage that cannot burn
away.

All chimneys need a weather cap and varmint barrier.

YMMV

Steve

Heart surgery pending?
www.cabgbypasssurgery.com

"Steve B" wrote

All chimneys need a weather cap and varmint barrier.


After having a bird, then a squirrel, I agree wholeheartedly. Best it SS so
it does not rust and discolor the side of the house.

On Wed, 06 Apr 2011 15:44:07 -0700, Joe wrote:

Take your specs to a good sheet metal shop and have them build you one.
There are nice coated sheet metal types available today that are perfect
for painting. If you get one made with these modified galvanized
materials it should last for many years.

Here (finally) is a picture of the ruined metal enclosure.
http://www.upload3r.com/serve/080411/1302291053.jpg

I was wrong on the specs - it's about 2 1/2 feet tall, about 5 feet long,
and about 2 feet wide (that's a yardstick on the ground in the pic, for
scale).

The enclosure appears to be of galvanized steel, riveted together.

What I would need, to withstand the frequent 100mph winds, is to
reinforce or brace it a bit better.

But that still leaves open the question whether this chimney enclosure is
merely aesthetic or functional.

On Thu, 07 Apr 2011 04:58:04 -0400, mm wrote:
You don't say what you burn that needs a chimney, or what the chimneys
are made of.

The chimney appears to be concrete (at least on the outside).

The only things, I think, that are burned up in this chimney that go out
the three spaceship-like "things" on top of the chimney (spark
arrestors?) are (1) the propane-fired water heater, (2) propane-fired
fireplace, and (3) wood-fired fireplace.

Here, for example, is a picture I just took of the three 'things'
sticking out.
http://www.upload3r.com/serve/080411/1302291372.jpg

What are these three 'things'?

Aaron FIsher wrote:
On Wed, 06 Apr 2011 15:44:07 -0700, Joe wrote:

Take your specs to a good sheet metal shop and have them build you
one. There are nice coated sheet metal types available today that
are perfect for painting. If you get one made with these modified
galvanized materials it should last for many years.

Here (finally) is a picture of the ruined metal enclosure.
http://www.upload3r.com/serve/080411/1302291053.jpg

I was wrong on the specs - it's about 2 1/2 feet tall, about 5 feet
long, and about 2 feet wide (that's a yardstick on the ground in the
pic, for scale).

The enclosure appears to be of galvanized steel, riveted together.

What I would need, to withstand the frequent 100mph winds, is to
reinforce or brace it a bit better.

But that still leaves open the question whether this chimney
enclosure is merely aesthetic or functional.

i'd vote for cosmetic

On Wed, 06 Apr 2011 15:58:36 -0700, ransley wrote:
Post a photo, its there for keeping smoke away by being high. your
setup seems humerous, or dumb.

Here is a photo I just took of the other chimney (with an intact metal
enclosure). This enclosure is open to the sky. Is it aesthetic or
functional?
http://www.upload3r.com/serve/080411/1302294051.jpg

Here is a photo of the three items inside the metal enclosure. Are they
spark arrestors? If I have to guess, the three "spark arrestors?" seem to
be for the wood-burning fireplace, the propane-burning fireplace, and the
hot-water heater. One got tilted over when I took the enclosure down (it
was very heavy and high above me on the top of the chimney so I wasn't
graceful.)
http://www.upload3r.com/serve/080411/1302291372.jpg

And, here is a picture of the metal enclosure back down on the ground. It
seems to be riveted together and is about 2 1/2 feet high, 5 feet long,
and about 2 feet wide (see the yardstick on the ground for reference).
http://www.upload3r.com/serve/080411/1302291053.jpg

My questions:
1. How to fabricate a STRONGER enclosure (that can be assembled on the
roof) on top of a chimney by 1 person?

2. What is the purpose of this thing? (Aesthetic or functional?)

On Wed, 06 Apr 2011 22:50:10 -0400, Ed Pawlowski wrote:
It may be functional and required by code. The chimney must extend some
distance higher than anything with in some distance of the chimney.

I don't think the enclosure is intended to make the chimney extend any
farther than it already does because (a) the chimney is already over five
feet above the roofline, and (b) the metal enclosure isn't any higher
than the three 'spark arrestors?' on the top of the chimney anyway.

The roof is tile and the chimney is, what appears to be, concrete of some
sort.

Here is a pic of the chimney that is intact:
http://www.upload3r.com/serve/080411/1302294051.jpg

And, the one where I had to take down the enclosu
http://www.upload3r.com/serve/080411/1302291372.jpg

And, a side view of the destroyed enclosure (don't ask how I got it down
all by myself):
http://www.upload3r.com/serve/080411/1302294453.jpg

What advice can you give me for replacing it?

What I'm thinking is to either leave it off (if it's not functional) or
to assemble a new one on the roof.

Aaron FIsher wrote:
On Wed, 06 Apr 2011 15:58:36 -0700, ransley wrote:
Post a photo, its there for keeping smoke away by being high. your
setup seems humerous, or dumb.

Here is a photo I just took of the other chimney (with an intact metal
enclosure). This enclosure is open to the sky. Is it aesthetic or
functional?
http://www.upload3r.com/serve/080411/1302294051.jpg

Here is a photo of the three items inside the metal enclosure. Are
they spark arrestors? If I have to guess, the three "spark
arrestors?" seem to be for the wood-burning fireplace, the
propane-burning fireplace, and the hot-water heater. One got tilted
over when I took the enclosure down (it was very heavy and high above
me on the top of the chimney so I wasn't graceful.)
http://www.upload3r.com/serve/080411/1302291372.jpg

And, here is a picture of the metal enclosure back down on the
ground. It seems to be riveted together and is about 2 1/2 feet high,
5 feet long, and about 2 feet wide (see the yardstick on the ground
for reference). http://www.upload3r.com/serve/080411/1302291053.jpg

My questions:
1. How to fabricate a STRONGER enclosure (that can be assembled on the
roof) on top of a chimney by 1 person?

2. What is the purpose of this thing? (Aesthetic or functional?)

actually, it might be functional. if you have a strong wind go over the top
of that, it may create a stronger draw via the bernoulli effect than if it
wasn't there. the vents on the bottom were the clue.

if the sides were bowed instead of flat, they'd shed wind load better.

On Thu, 07 Apr 2011 05:59:28 -0400, Ed Pawlowski wrote:
That should be OK. Three feet above the roof where it comes out Two
feet above anything within 10 feet.

The 'bottom' of this enclosure (i.e., the top of the chimney) is 'way'
higher than that!

While I'm on the downslope of the chimney, it's above my head just to the
'bottom' of the enclosure; and at the upslope roof side it's about at eye
level to the top of the chimney (i.e., the bottom of the metal enclosure).

With those three 'spark arrestor?' things sticking out, I don't really
think the enclosure is for fire purposes. I suspect there's some other
intent.

Again, here's a pic with the enclosure removed:
http://www.upload3r.com/serve/080411/1302291372.jpg

And, here's a pic of the enclosure back on the ground:
http://www.upload3r.com/serve/080411/1302291053.jpg

What I'm thinking (hoping?) is I can pre-fabricate the 2.5 feet high by 5
feet long by 2 feet wide thing on the ground, and then assemble it up on
the roof. Then I have to figure out how to brace it against 100mph winds.

Any ideas?

On Thu, 07 Apr 2011 05:24:45 -0700, Steve B wrote:
When dealing with height, any increase increases the leverage put on it
by wind.

Hi Steve,
The one that was there must have been there a while (I have no idea how
long though, as the house is 30 years old).

It's made out of sheet steel, galvanized probably as there is no rust,
and it is pretty darn heavy (at least while I was on the roof, on my tip
toes, my arms over my head, trying to wrestle it off the chimney itself).

The chimney is way higher on the roof that you guys seem to intimate.
It's at my eye level on the upslope and well over my head on the
downslope side.

The winds here are easily 100mph with gusts that are higher, so, that's
pretty much what killed the prior metal enclosure. It really needs to be
braced better.

But, I can't possibly solve the problem until I figure out WHAT the roof
enclosure's purpose is.

Here, again, is a picture of the enclosure on the other chimney:
http://www.upload3r.com/serve/080411/1302294051.jpg

And, the things (spark arrestors?) it's "protecting" on the affected
chimney:
http://www.upload3r.com/serve/080411/1302291372.jpg

On Thu, 07 Apr 2011 08:09:34 -0700, hr(bob) wrote:
I sounds like the chimney surround is higher than the individual
chiumney stacks from the individual units. A photo of that's on the
roof now, and a photo of what was removed would sure help!!!!

I 'should' have taken a picture of the enclosure BEFORE I took it down,
but, alas, I hadn't thought of that ahead of time.

But, here is a picture I took today of the 'other' chimney, which has
what appears to be an identical chimney enclosure (purpose unknown):
http://www.upload3r.com/serve/080411/1302294051.jpg

And, here is a picture of the affected chimney, sans steel enclosu
http://www.upload3r.com/serve/080411/1302291372.jpg

And, here is a picture of the enclosure on the ground:
http://www.upload3r.com/serve/080411/1302294453.jpg

Here is a side view showing construction details of the enclosu
http://www.upload3r.com/serve/080411/1302295784.jpg

What else by way of information can I give you guys to help me figure out
my next step?

On Fri, 08 Apr 2011 13:41:30 -0700, chaniarts wrote:
actually, it might be functional. ... the vents on the bottom were the
clue.

Amazing! I didn't even 'notice' those 'vents' on the bottom!
http://www.upload3r.com/serve/080411/1302294051.jpg

if the sides were bowed instead of flat, they'd shed wind load better.

Interesting. I'm not sure 'how' to do that, but I do agree.

I was thinking more about BRACING the heck out of a new one.
And fabricating it on the ground, and assembling on the roof.

Of course, the problem is the chimney is something like six feet tall on
the short end and something like 7 or 8 feet tall on the long (downslope)
end, so, getting on top of it is problematic.

But, there must be a way to do this!

Anyone know of a DIY?

Aaron FIsher wrote:
On Fri, 08 Apr 2011 13:41:30 -0700, chaniarts wrote:
actually, it might be functional. ... the vents on the bottom were
the clue.

Amazing! I didn't even 'notice' those 'vents' on the bottom!
http://www.upload3r.com/serve/080411/1302294051.jpg

if the sides were bowed instead of flat, they'd shed wind load
better.

Interesting. I'm not sure 'how' to do that, but I do agree.

when you get it fabricated, you can specify not only the dimensions, but how
much each side bows out as long as each side is straight at the bottom
(hint: each side will be a section of a cone). also, how it attaches to the
chimney will be a critical measurement unless you want to redo that also.

I was thinking more about BRACING the heck out of a new one.
And fabricating it on the ground, and assembling on the roof.

well, yes. you can put braces on the top and bottom going across between the
stacks. you'd have to make good measurements of the top for someone to build
this for you. i'd get them to use pretty heavy braces.

Of course, the problem is the chimney is something like six feet tall
on the short end and something like 7 or 8 feet tall on the long
(downslope) end, so, getting on top of it is problematic.

But, there must be a way to do this!

got a friend with a crane? you might try calling places that replace a/c
units. in my area, most a/c units are on the roof, and they just crane off
the old one and lift on the new one. takes about 20 minutes once they're all
set up. it might cost you some for crane rental time.


Anyone know of a DIY?

you might ask on rec.crafts.metalworking. at the least, you're going to need
some pretty heavy duty tools: metal brake, shears, welding and/or drilling
and bolting it together, etc. it's going to be heavy too. this isn't a
typical diy job.

in my area, they do this with either sheet metal, like yours, or by building
a metal rod frame, tying on a heavy chickenwire or expanded metal sheet, and
doing a stucco job over that in place.

In article ,
Aaron FIsher wrote:


What else by way of information can I give you guys to help me figure out
my next step?

As to whether it's aesthetic or functional, it could well be both. It's
certainly aesthetic, because those other things are ugly as sin without
the cap.

As to whether it's also functional, without a pic looking down into the
chimney, I can't tell how well those protrusions are secured, nor if the
chimney is functionally capped without the appendage.

Also can't tell how - or how well - the intact unit is secured to the
other chimney. Seems like there isn't much overlap, and perhaps you'd
consider a larger overlap if you're going to rebuild the trashed unit.

This was probably, as someone said, pre-fabbed and craned to the
location. For a single cost data point, my friend with a small,
light-duty crane has a minimum fee of $300, for which he'll drive his
rig about 10 miles and work for an hour.

However, parts of it at least are pop-riveted together, and you could do
that in situ. You might also consider pem nuts.

100 mph is a stiff breeze, and personally, I'd not put anything that big
on a roof exposed to that kind of load, by guessing at the engineering.
The work could by DIY, but depending on the proximity of your nearest
neighbors, you might reconsider winging the design.

On Fri, 08 Apr 2011 15:36:46 -0700, Smitty Two wrote:
As to whether it's also functional, without a pic looking down into the
chimney, I can't tell how well those protrusions are secured, nor if the
chimney is functionally capped without the appendage.

Ah. Good question.

I don't have a picture of that (I'd have to crack a few more roof tiles
to do that!) but the chimney is totally 'capped' (if I understand you).

By that I mean, if you removed those three (spark arrestors?) from the
chimney, all you'd have on the horizontal part are the three holes where
they came out of the otherwise concrete flat top of the chimney.

Is 'that' what you mean by functionally 'capped'?

On Fri, 08 Apr 2011 15:36:46 -0700, Smitty Two wrote:
Also can't tell how - or how well - the intact unit is secured to the
other chimney. Seems like there isn't much overlap, and perhaps you'd
consider a larger overlap if you're going to rebuild the trashed unit.

There is a short length of what appears to be just under five inches of
light "angle iron" at each corner of the steel enclosure.

Here is a picture from the side that shows the remaining three corner
attachments (the fourth came down with the enclosure):
http://www.upload3r.com/serve/080411/1302302091.jpg

The four 'corners' are NOT made of 'real' angle iron; they're definitely
made of the same sheet steel that the enclosure is made out of. It's bent
in the shape of an angle, and then folded over partway where the three
screws are screwed into the chimney and into the enclosure.

Two of the three screws on each of the two edges of the V-shaped corner
piece are screwed with a 5/8" long screw into the chimney and the third
screw is screwed into the sheet metal holding it onto the corner piece.

All in all, it looks like a pretty flimsy support to me considering the
side-of-a-barn profile to the wind.

Certainly I'd use more substantial corner supports & longer screws for
the two bottom ones. And, instead of the same (sheet metal?) screws, I'd
use a concrete screw (if that exists) for the bottom two screws holding
the 'angle iron' to the chimney.

It's hard to explain, but the picture above should show it in situ.

In article ,
Aaron FIsher wrote:

On Fri, 08 Apr 2011 15:36:46 -0700, Smitty Two wrote:
As to whether it's also functional, without a pic looking down into the
chimney, I can't tell how well those protrusions are secured, nor if the
chimney is functionally capped without the appendage.

Ah. Good question.

I don't have a picture of that (I'd have to crack a few more roof tiles
to do that!) but the chimney is totally 'capped' (if I understand you).

By that I mean, if you removed those three (spark arrestors?) from the
chimney, all you'd have on the horizontal part are the three holes where
they came out of the otherwise concrete flat top of the chimney.

Is 'that' what you mean by functionally 'capped'?

Yes, and, provided those three gadgets are properly secured to said
horizontal surface where they pass through it, then I'd say your
contraption is aesthetic only.

IANARNACE, of course. (I am not a roofer nor a chimney expert)

Smitty Two wrote:
In article ,
Aaron FIsher wrote:

On Fri, 08 Apr 2011 15:36:46 -0700, Smitty Two wrote:
As to whether it's also functional, without a pic looking down into
the chimney, I can't tell how well those protrusions are secured,
nor if the chimney is functionally capped without the appendage.

Ah. Good question.

I don't have a picture of that (I'd have to crack a few more roof
tiles to do that!) but the chimney is totally 'capped' (if I
understand you).

By that I mean, if you removed those three (spark arrestors?) from
the chimney, all you'd have on the horizontal part are the three
holes where they came out of the otherwise concrete flat top of the
chimney.

Is 'that' what you mean by functionally 'capped'?

Yes, and, provided those three gadgets are properly secured to said
horizontal surface where they pass through it, then I'd say your
contraption is aesthetic only.

IANARNACE, of course. (I am not a roofer nor a chimney expert)

if that's correct, then what about making this using expanded metal rather
than sheet metal? that would reduce the wind load a lot, but still hide the
stacks. it might whistle a lot though

On Fri, 08 Apr 2011 16:00:28 -0700, chaniarts wrote:
if that's correct, then what about making this using expanded metal
rather than sheet metal?

Expanded metal?

On Apr 8, 7:13*pm, Aaron FIsher wrote:
On Fri, 08 Apr 2011 16:00:28 -0700, chaniarts wrote:
if that's correct, then what about making this using expanded metal
rather than sheet metal?

Expanded metal?

I vote for purely aesthetic. The three stacks are ugly as sin, with
the surround the chimney is only regular ugly. A new surround out of
aluminum would get my vote for replacement materialss. There is
nothing wrong with making use of pop rivets to hold the surround
together, as long as it is sturdily constructed. You might consider
pop riveting the new surround to the lower base unit to help
strengthen the new unit. You also could do a lot on interior bracing
of the new surround using aluminum angles and rods. The only thing
that would be visible on the outside would be the rivets, and from
street level I can't believe that would be objectionable.

On Fri, 8 Apr 2011 19:48:40 +0000 (UTC), Aaron FIsher
wrote:

On Thu, 07 Apr 2011 04:58:04 -0400, mm wrote:
You don't say what you burn that needs a chimney, or what the chimneys
are made of.

The chimney appears to be concrete (at least on the outside).

The only things, I think, that are burned up in this chimney that go out
the three spaceship-like "things" on top of the chimney (spark
arrestors?) are (1) the propane-fired water heater, (2) propane-fired
fireplace, and (3) wood-fired fireplace.

Here, for example, is a picture I just took of the three 'things'
sticking out.
http://www.upload3r.com/serve/080411/1302291372.jpg

What are these three 'things'?

As you suspect, they are parts of rockets. Civil Defenese workers and
survivalists often included special preparations in their homes for
times of unrest. The exhaust gases from the three things you mention
are not sufficient to ignite the rocket engines until their ignition
has been enabled. He must have left instructions to do that, right?

If not, try www.civildefense.gov/homepreparedness .


On second look, those are chimney caps. What you took off is just a
cabinet, to cover from view your ramshackle flues** and non-matching
chimney caps.

**Especally the middle one.

I'm not sure but I would ask someone who knows more if the cover,
given how high it is compared to the chimneys, reduces chimney draw.

I guess if the flue is hot the chimney draw is mostly dependant on the
height. Maybe I'm confusing it with turbine attic exhaust fans, which
have to have a breeze to work, but before I built another decorative
cover, I'd check with a chimney company. Here we have a couple
chimeny sweeps who expanded to all aspects of chimneys (plus another
one who never expanded and low-balls and then tries to sell unneeded
$300 pipes for $700 dollars, but that's another story.)

On Fri, 08 Apr 2011 15:36:46 -0700, Smitty Two
wrote:

In article ,
Aaron FIsher wrote:


What else by way of information can I give you guys to help me figure out
my next step?

As to whether it's aesthetic or functional, it could well be both. It's
certainly aesthetic, because those other things are ugly as sin without
the cap.

But it's not a cap, it's aa box. With no top, right? Now that I
see it's tapered it looks a lot better, but still my previous doubts
obtain. Go talk to the guy who owns the other chimney and ask him all
about it. Find out why his didn't bend, if it thwarts the draft, and
maybe he knows where it was made and you can get another there.
Especially good if it is a stock item somewhere -- I doubt it, but
ask.

As to whether it's also functional, without a pic looking down into the
chimney, I can't tell how well those protrusions are secured, nor if the
chimney is functionally capped without the appendage.

The suspected fire arresters picture wouldn't work for me.

Also can't tell how - or how well - the intact unit is secured to the
other chimney. Seems like there isn't much overlap, and perhaps you'd
consider a larger overlap if you're going to rebuild the trashed unit.

This was probably, as someone said, pre-fabbed and craned to the
location. For a single cost data point, my friend with a small,
light-duty crane has a minimum fee of $300, for which he'll drive his
rig about 10 miles and work for an hour.

However, parts of it at least are pop-riveted together, and you could do
that in situ. You might also consider pem nuts.

100 mph is a stiff breeze, and personally, I'd not put anything that big
on a roof exposed to that kind of load, by guessing at the engineering.
The work could by DIY, but depending on the proximity of your nearest
neighbors, you might reconsider winging the design.

On Fri, 8 Apr 2011 22:42:47 +0000 (UTC), Aaron FIsher
wrote:

On Fri, 08 Apr 2011 15:36:46 -0700, Smitty Two wrote:
As to whether it's also functional, without a pic looking down into the
chimney, I can't tell how well those protrusions are secured, nor if the
chimney is functionally capped without the appendage.

Ah. Good question.

I don't have a picture of that (I'd have to crack a few more roof tiles
to do that!) but the chimney is totally 'capped' (if I understand you).

By that I mean, if you removed those three (spark arrestors?) from the

I get it now. No, those are chimey caps. They also function as spark
arrestors, but they are called chimney caps.

chimney, all you'd have on the horizontal part are the three holes where
they came out of the otherwise concrete flat top of the chimney.

No, you'd have the pipes that go into the caps. The chimneys. All
three pipes are visible in the picture. I don't like to fiddle with
mine but aiui they clip onto the chimneys with a built-in clip. My
first experience with mine was when it blew off, after the clips
failed, so that's why I don't try to take off the replacement, just to
see how it works.

Is 'that' what you mean by functionally 'capped'?

In article ,
Aaron FIsher wrote:

On Fri, 08 Apr 2011 16:00:28 -0700, chaniarts wrote:
if that's correct, then what about making this using expanded metal
rather than sheet metal?

Expanded metal?

Do a google image search.

On Sat, 9 Apr 2011 00:13:43 +0000 (UTC), Aaron FIsher
wrote:

On Fri, 08 Apr 2011 16:00:28 -0700, chaniarts wrote:
if that's correct, then what about making this using expanded metal
rather than sheet metal?

Expanded metal?

Expanded metal is sheet metal with a lot of cuts in it, in alternating
rows offset by half a cycle, and then pulled apart somehow so that
each cut becomes a diamond shaped hole. A narrow diamond, compared to
its height, compared to a diamond on a playing card.

It's used various places, maybe the grill inside a charcoal stove;
definitely the bottom of most cargo carriers that fit into trailer
hitches and are 20" front to back and 5 feet wide. Maybe even iirc
the seat of some outdoor wrought iron furniture, above which goes an
upholestered cushion.

That's why it might well whistle. Probably would at some wind speeds.

On Sat, 09 Apr 2011 01:38:28 -0400, mm
wrote:

On Sat, 9 Apr 2011 00:13:43 +0000 (UTC), Aaron FIsher
wrote:

On Fri, 08 Apr 2011 16:00:28 -0700, chaniarts wrote:
if that's correct, then what about making this using expanded metal
rather than sheet metal?

Expanded metal?

Expanded metal is sheet metal with a lot of cuts in it, in alternating

Not sheet metal I mean, something thicker than that.

The steel version is pretty heavy. Do they make it in aluminum?

YOu can see through it some, and but maybe from the ground they won't
be able to see the ugly stuff underneat.

rows offset by half a cycle, and then pulled apart somehow so that
each cut becomes a diamond shaped hole. A narrow diamond, compared to
its height, compared to a diamond on a playing card.

It's used various places, maybe the grill inside a charcoal stove;
definitely the bottom of most cargo carriers that fit into trailer
hitches and are 20" front to back and 5 feet wide. Maybe even iirc
the seat of some outdoor wrought iron furniture, above which goes an
upholestered cushion.

That's why it might well whistle. Probably would at some wind speeds.

On Sat, 09 Apr 2011 00:30:42 -0400, mm wrote:

They also function as spark
arrestors, but they are called chimney caps.

OK. I'll call them 'chimney caps' from now on.

the pipes that go into the caps. The chimneys.

Ah. I see. OK. I have three chimneys, with three chimney caps, and an
enclosure for aesthetics. Is that right?


it blew off, after the clips failed,

One of my chimney caps is tilted slightly from when I took off the heavy
steel enclosure. I can 'clip' it back on ... but somehow I have to get
from the roof to the top of the chimney.

I can try a stepladder - but those tiles. Oh those tiles. Is there a good
technique for putting a ladder on the chimney (30 feet up in the air)
without breaking the tiles? (I'll probably use a board under the
stepladder legs; but that might be slippery.)