Add on Chimney

(Mark Ellison, CMI) #1

I’ve never seen this before. Brick chimney serves main floor aftermarket gas insert (was wood burner) metal liner present. Steel chimney attached laterally to the masonry chimney for basement wood burning fireplace.
I know side by side clearance is 16" min on metal vents, but what about metal to masonry. I didn’t measure but I believe steel vent has it’s two feet over ridge.

My concern is what I can’t see Re: the basement fire box/throat/off-set to the vent connection.

What say you?

Cheers

Mark

(KEVIN WOOD, CMI) #2

The National Standard of Canada, Installation Code for Solid Fuel Burning Appliances
and Equipment, CSA-B365-01 clause 5.2.9 states that:

Two or more appliances shall not be connected to the same chimney flue unless:

1) The appliances are located on the same story;
2) A negative pressure is maintained at the flue collar of each appliance;
3) Each appliance is provided with a means to control the rate of flow of air or flue
gases through the appliance combustion and heat exchanger chambers. Where
limitations on flue pressure (draft) are contained in the manufacturer’s instructions,
such means shall be capable of maintaining at the flue collar, the pressure
specified by the appliance manufacture; NOTE: For the purpose of this Clause,
draft controls include ash pit air control dampers, dampers or draft slides wherever
located, over fire and flue key pipe dampers, and check draft controls located on or
in the flue pipe.
4) The flue pipes of the appliances are connected to a manifold as close to the
chimney as practicable or directly to the chimney in the following order:
(i) If only solid fuel is used, the flue pipe from the smallest appliance shall be on
top (downstream);
(ii) If different fuels are used as permitted in Clause 5.2.7, the oil flue pipe shall be
on top (downstream); and the solid fuel flue pipe on the bottom (upstream); and
5) The chimney flue is capable of venting the flue gas by natural draft when all
appliances not interlocked to prevent simultaneous firing are firing at their
maximum rate at the same time.

When installing a wood-burning appliance to an existing chimney carefully inspect entire
chimney for the presence of old inlet holes, which may be improperly covered by metal
caps or other unacceptable means. Fill any openings with brick and mortar to ensure
no hazardous openings exist.

(Chris Jacobi, HI01200061) #3
  1. One flue for one wood burning fireplace. It's hard to tell from your pics, but I'm wondering if they share the flue at any point. If they do, that's a no-no.
  2. Metal vent: It may be 2' higher than the ridge, but it's not 2' higher than the chimney chase.
  3. Enough clearance through the soffit? Shouldn't there be a thimble/coller?
(KEVIN WOOD, CMI) #4

The National Standard of Canada, Installation Code for Solid Fuel Burning Appliances
and Equipment, CSA-B365-01 clause 5.2.9 states that:

Two or more appliances shall not be connected to the same chimney flue unless:

1) The appliances are located on the same story;
2) A negative pressure is maintained at the flue collar of each appliance;
3) Each appliance is provided with a means to control the rate of flow of air or flue
gases through the appliance combustion and heat exchanger chambers. Where
limitations on flue pressure (draft) are contained in the manufacturer’s instructions,
such means shall be capable of maintaining at the flue collar, the pressure
specified by the appliance manufacture; NOTE: For the purpose of this Clause,
draft controls include ash pit air control dampers, dampers or draft slides wherever
located, over fire and flue key pipe dampers, and check draft controls located on or
in the flue pipe.
4) The flue pipes of the appliances are connected to a manifold as close to the
chimney as practicable or directly to the chimney in the following order:
(i) If only solid fuel is used, the flue pipe from the smallest appliance shall be on
top (downstream);
(ii) If different fuels are used as permitted in Clause 5.2.7, the oil flue pipe shall be
on top (downstream); and the solid fuel flue pipe on the bottom (upstream); and
5) The chimney flue is capable of venting the flue gas by natural draft when all
appliances not interlocked to prevent simultaneous firing are firing at their
maximum rate at the same time.

When installing a wood-burning appliance to an existing chimney carefully inspect entire
chimney for the presence of old inlet holes, which may be improperly covered by metal
caps or other unacceptable means. Fill any openings with brick and mortar to ensure
no hazardous openings exist.

Judging from the size of the gas insert. It is possible for this to be completely separate. However I would not want to call that safe as you would need to anchor to the original chimney and that is not accepted. You also need proper brackets all the way up to the top anchored somewhere.

(Mark Ellison, CMI) #5

The SS vent is definitely not sharing a flue. It’s not easy to see the in the pic, but the SS vent connection is well below the main floor level, which prevents it from sharing the flue. I believe the termination up top is poor. I’m mainly concerned with the side connection to the main brick chase. The off set must be great, but I can’t see anything. It’s a manufactured fireplace in the basement. Fasteners are present Kevin

(KEVIN WOOD, CMI) #6

I do not see any brackets or straps unless they are attached at the wall and very well hidden from this picture.

(Mark Ellison, CMI) #7

[quote="kwood, post:6, topic:82660"]

I do not see any brackets or straps unless they are attached at the wall and very well hidden from this picture.
[/QUOTE]

Not to worry Kevin, they are there. I just didn't post a pic showing them.

(KEVIN WOOD, CMI) #8

It is wrong anyways!

(Juan C. Jimenez) #9

[quote="kwood, post:8, topic:82660"]

It is wrong anyways!
[/QUOTE]

What is wrong about it? Do you have a reference to something I can read?

(Juan C. Jimenez) #10

Here's a link I found

http://www.fornobravo.com/PDF/duratech.pdf

(Juan C. Jimenez) #11

Mark what about condensation and draft since its outside? Was it an insulated type?

(Juan C. Jimenez) #12

[quote="cjacobi, post:3, topic:82660"]

  1. Enough clearance through the soffit? [/QUOTE]

It's fuzzy in the photo, but looks like there could be the 2" gap there.

(Mark Ellison, CMI) #13

That's a great document Juan, thanks.
What I'm unsure of is the lateral connection of the SS vent to the brick chase at the exterior of the chimney, at the basement level. The clearance at the vent termination as well as the fireplace clearances are all wrong.

(Juan C. Jimenez) #14

[quote="mellison, post:13, topic:82660"]

That's a great document Juan, thanks.
What I'm unsure of is the lateral connection of the SS vent to the brick chase at the exterior of the chimney, at the basement level. The clearance at the vent termination as well as the fireplace clearances are all wrong.
[/QUOTE]

What's wron with the termination? Did you check to see if its a zero clearance fireplace?

(Mark Ellison, CMI) #15

[quote="jjimenez, post:14, topic:82660"]

What's wron with the termination? Did you check to see if its a zero clearance fireplace?
[/QUOTE]

The SS chimney should be at least 2 ft higher than the masonry chimney. It serves a wood burner Juan, not a gas insert. It's the masonry chimney that serves the aftermarket gas insert.

(Juan C. Jimenez) #16

[quote="mellison, post:15, topic:82660"]

The SS chimney should be at least 2 ft higher than the masonry chimney.
[/QUOTE]

Why?

(Mark Ellison, CMI) #17

[quote="jjimenez, post:16, topic:82660"]

Why?
[/QUOTE]

Must be 2 ft above anything within 10 ft.

(Juan C. Jimenez) #18

[quote="mellison, post:17, topic:82660"]

Must be 2 ft above anything within 10 ft.
[/QUOTE]

How is different than two flues in the same chimney? They only need to be 4 inches apart. Is it different in this scenario?

If you extend one of them two feet above the other, wouldn't the other be in violation?

(Michael Marrero) #19

This is differently different from what I have seem before, hopefully there is enough space so it would not cause any safety violation.

(Erik Schmidt) #20

The metal chimney looks to be A vent with stainless steel cladding, and SS liner, so clearance from combustibles is 1 inch, check for a label.
I would prefer to see both chimneys at the same height. The reason for 2’ above rule is to prevent back drafting caused by wind eddies or low pressure zones when wind passes over the too close obstruction, a roof ridge, wall or similar, a relatively skinny masonry or metal chimney close by is unlikely to cause this.
If a wood burning fireplace does back draft the people sitting in front will know it is happening right away.
So, tell them about it, but IMO chimney installation in pics is not a concern.