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Bill
 
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Default New s.s. metal chimney and cutting roof rafter?

I am installing a new wood stove (EPA Cert.), have mechanical permit, etc.

And I have built my hearth pad (proper R-Value to code, etc.) and have
located my wood stove on the hearth pad to manufacturer's specs. (Proper
distance from walls, etc.) This is the *only* place the wood stove can go.
The chimney is stainless steel 6" inside diameter and 8" outside diameter.
I'm Using Selkirk - Metalbestos chimney parts.

So guess what? The metal chimney going straight up will go right smack dab
through a rafter (45 deg. roof slope - one of many 2 x 4's at 45 deg. angle
supporting roof.)

So I will need to cut the rafter....

Questions....

Can I cut the rafter, then add 2x 4's which transfer the support for that
rafter to neighboring rafters?

I read that there needs to be a 2 inch separation between wood and the
metal chimney. If I do this where the chimney pops up through the roof,
there will be a 2" air gap going from the attic to the vented roof jack
(flashing). I am concerned about insects getting into the vent, then making
a home in the attic. Can I place screen or something somewhere in this area
(to keep insects out)?


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RicodJour
 
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Bill wrote:
I am installing a new wood stove (EPA Cert.), have mechanical permit, etc.

And I have built my hearth pad (proper R-Value to code, etc.) and have
located my wood stove on the hearth pad to manufacturer's specs. (Proper
distance from walls, etc.) This is the *only* place the wood stove can go.
The chimney is stainless steel 6" inside diameter and 8" outside diameter.
I'm Using Selkirk - Metalbestos chimney parts.

So guess what? The metal chimney going straight up will go right smack dab
through a rafter (45 deg. roof slope - one of many 2 x 4's at 45 deg. angle
supporting roof.)

So I will need to cut the rafter....

Questions....

Can I cut the rafter, then add 2x 4's which transfer the support for that
rafter to neighboring rafters?

I read that there needs to be a 2 inch separation between wood and the
metal chimney. If I do this where the chimney pops up through the roof,
there will be a 2" air gap going from the attic to the vented roof jack
(flashing). I am concerned about insects getting into the vent, then making
a home in the attic. Can I place screen or something somewhere in this area
(to keep insects out)?



There's not a lot of extra strength in a 2x4, I would not want to add
additional loads to the flanking rafters without reinforcing them.

Buy an adjustable elbow or two, and run the chimney so it avoids the
rafters altogether. It's a much easier and better way to do it.

R

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HotRod
 
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Default

Installed a Propane Selkirk unit last year and didn't have any problems with
to much heat transferring to the outside 8" pipe since fresh air returns
through the gap. Any chance of venting out the wall? Otherwise I'd try and
use an elbow to change the angle. If that's not an option transfer the load
but you'll need to support them. Also Selkirk has a piece of steel plate
that is designed specifically for going through walls and creating the 2"
space without allowing bugs back through, it's also a perfect 8" hole.


"Bill" wrote in message
...
I am installing a new wood stove (EPA Cert.), have mechanical permit, etc.

And I have built my hearth pad (proper R-Value to code, etc.) and have
located my wood stove on the hearth pad to manufacturer's specs. (Proper
distance from walls, etc.) This is the *only* place the wood stove can go.
The chimney is stainless steel 6" inside diameter and 8" outside diameter.
I'm Using Selkirk - Metalbestos chimney parts.

So guess what? The metal chimney going straight up will go right smack dab
through a rafter (45 deg. roof slope - one of many 2 x 4's at 45 deg.
angle
supporting roof.)

So I will need to cut the rafter....

Questions....

Can I cut the rafter, then add 2x 4's which transfer the support for that
rafter to neighboring rafters?

I read that there needs to be a 2 inch separation between wood and the
metal chimney. If I do this where the chimney pops up through the roof,
there will be a 2" air gap going from the attic to the vented roof jack
(flashing). I am concerned about insects getting into the vent, then
making
a home in the attic. Can I place screen or something somewhere in this
area
(to keep insects out)?




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kevin
 
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Default

Get some more opinions, but I would think transfering the load
shouldn't be a big deal as long as the spacing on your rafters is small
enough. If so, I'd probably think about reinforcing the neighboring
rafters with, say, a 6' length of 2x4, then making the chimney box
right in the middle of the reinforced area using 2x4s to connect the
three rafters together.

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Edwin Pawlowski
 
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Default


"Bill" wrote in message

So guess what? The metal chimney going straight up will go right smack dab
through a rafter (45 deg. roof slope - one of many 2 x 4's at 45 deg.
angle
supporting roof.)

So I will need to cut the rafter....


There are ways of boxing around the stack, but it may be easier and cheaper
to buy a couple of 45 degree elbows and zig around hte 2 x 4.




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DanG
 
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Default

The traditional way to do this would be to double the rafter on
each side of the one to be cut, install a header between these
rafters to carry the cut rafter. You should support the load
until all the connections are made, though the roof will probably
carry it long enough to accomplish.

If the rafters are 2x4, it must be a fairly old structure. What
worries me is that they may be trusses. DO NOT CUT A TRUSS. Get
further input and advice.

(top posted for your convenience)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Keep the whole world singing . . . .
DanG (remove the sevens)




"Bill" wrote in message
...
I am installing a new wood stove (EPA Cert.), have mechanical
permit, etc.

And I have built my hearth pad (proper R-Value to code, etc.)
and have
located my wood stove on the hearth pad to manufacturer's specs.
(Proper
distance from walls, etc.) This is the *only* place the wood
stove can go.
The chimney is stainless steel 6" inside diameter and 8" outside
diameter.
I'm Using Selkirk - Metalbestos chimney parts.

So guess what? The metal chimney going straight up will go right
smack dab
through a rafter (45 deg. roof slope - one of many 2 x 4's at 45
deg. angle
supporting roof.)

So I will need to cut the rafter....

Questions....

Can I cut the rafter, then add 2x 4's which transfer the support
for that
rafter to neighboring rafters?

I read that there needs to be a 2 inch separation between wood
and the
metal chimney. If I do this where the chimney pops up through
the roof,
there will be a 2" air gap going from the attic to the vented
roof jack
(flashing). I am concerned about insects getting into the vent,
then making
a home in the attic. Can I place screen or something somewhere
in this area
(to keep insects out)?




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Bill
 
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Default

"DanG" wrote in message

...If the rafters are 2x4, it must be a fairly old structure. What
worries me is that they may be trusses. DO NOT CUT A TRUSS.
Get further input and advice.


I did just that, got further advice. I took pictures of everything and took
them to my building inspector...

I told him I had the option of cutting the rafter if I wanted my chimney to
go straight up from the wood stove, or using a 15 deg. or 30 deg. pair of
elbows up in the attic (max bend recommended by the chimney manufacturer)
to re-direct the chimney to come out between the rafters. I asked what to
do?

He said *DO NOT* cut the rafter!

Then he came up with a third idea. He said he preferred a pair of 15 deg.
elbows (not 30 deg.) and to place these elbows at the wood stove, not
higher up, or in the attic. He said it was better to place elbows lower
down rather than higher up.

This will save me money as the pipe coming out of the stove is single wall
and elbows at this location will be much less expensive than using Selkirk
s.s. insulated chimney elbows in the attic.

He also looked pleased that I was asking for advice in *advance* rather
than going ahead and doing the wrong thing, then having to fix my mistakes
after inspection.

So thanks for the advice to "get more advice"! This will be a lot less
work, less worry, and less cost. Can't beat that!


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