"cm" wrote
"Tony Hwang" wrote
cm wrote:

year ago. We tried several times last winter to have a fire and most of
the time smoke backed up in the house. We have tried having a window
partially/fully open and warming the chimney prior to lighting the logs,
with no luck.

2 sided? Can you define what you mean there? Is it one that is open to 2
roms at the same time (back and front) as like a center of the house chimney
may be?

If so, more often than not, the grate is too low in that configuration
causing smoke to go out the sides into one or both rooms. It's also
possible a fan or some other air source in one room is pushing the smoke
across into the other.

I measured the chimney height tonight and it is taller than it needs to
be. I was told it needs to be 2' taller than the point where it is 10'
away from the roof. There is a large rooftop A/C unit 7' feet away from
the chimney that is 2' taller than the chimney. Should I raise the
chimney above the A/C unit? What else should I look for?

Not bad, but doesnt sound likely just now that the AC unit is at fault.
There are other things to check first.

Hi,
I wonder if you have a damper to open?

Thanks. The damper is wide open when I light the fire. With a flashlight I
can see all the way to the top of the chimney.

Ok, you may actually have it too far open. Some fireplaces dont draw as
well with it all the way open. It sounds illogical, but it can be true.
Mine operates best at the 2/3 position for example. Open it too far, and
the wind makes the flow reverse into the house.

Here's a list of things to rule out.

- Is the grate too low or are you building the fire right on the base? The
fireplace design has to be made for that and most are not. Too much 'top
room' before the lintel can cause the smoke to redirect wrong.

- if with a grate, are you trying to build the fire more towards the center
or front? (assuming here your '2 sided' isnt the above where it's basically
an open hole between 2 rooms). Most fires will smoke and not draw right
unless the grate is pushed more towards the back (not flush to the wall, but
much nearer to it than the center).

- If a grate, is it too large? Many people get one too large for the
fireplace because visually 'it fits' but then the fire is too much for the
draw to handle. At a rough guess there should be at least 6 inches on each
side clear from the brick work.

- What kind of wood are you burning? Is it really properly cured? If it's
any type of pine, or you get lots of 'popping' then it's smoky green wood
(which can also be a fire hazard as it makes more creosote which can catch
fire in the chimney). If you arent familiar with burning wood, it's real
easy to not know the difference. If you have an experienced neighbor with a
fireplace, ask if you can have a bit of well cured wood for 1 fire to check
out, or perhaps they can come over and see what yours is doing and be able
to tell you.

- Is the wood damp? Wood that is damp or literally frozen, tends to be
smoky for a bit (and hard to light obviously!).

- Do you have a chimney cap? Such affects the flow of air but is needed,
but it may not be positioned right for your needs. It may for example be
too low. Such are normally sold for 'standard single sided fireplaces' and
if you have something special, may have to be adjusted for it. I have seen
ones that are higher and have a sort of 'chicken wire' down to the base of
the chimney to keep birds and squirrels etc out, on specialty (larger than
average) fireplaces.

- Have you had the chimney professionally cleaned (which comes with a basic
inspection as well and the cleaners normally know a fair amount about draft
issues and what can affect them, though may not know exact 'how many inches'
details for caps and such (hit or miss, some do, some don't).

The only thing there that is a little expensive, is the cleaning and
inspection. You dont need the fiber-optic cable inspection level (thats for
follow-up on a damaged one) but the basic one (normally about 100-120$ and
often you get 1/3 of that back from your house insurance company if you call
then bring the recipt in).

Please bear with me if you have a reply with questions and do not get an
answer from me. COX cable in my area is having problems with the newsgroup
servers the past 6 days and most days, all the messages 'go away'. My email
however is not grunged so if you want to also send me a copy of any replies
that way if you get no answer in a day or so, I am happy to help.