Replies

1. 
   plumbbill | Dec 26, 2006 06:28am | #1

   I would consider that to be back to back verses double sided.

   One chimney is doable but they need to have seperate dampers.

   & you wouldn't want the patio damper open while burning in the great room, & vise a versa.

   “How many observe Christ’s birthday! How few, his precepts! O! ‘tis easier to keep Holidays than Commandments.” —Benjamin Franklin

1. 
   Piffin | Dec 26, 2006 01:24pm | #3

   not only separate dampers, but separate flues too, or the drafting wil be a nightmare. 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

2. 
   Piffin | Dec 26, 2006 01:23pm | #2

   As you describe this, it is not a double sided fireplace. It is simply two fireplaces oriented back to back. Each would require its own flue up the chimney and it's own damper. Having 2, 3, or even 4 fireplaces share the same chimney is not at all uncommon.

   designing for space and size -
   A mason who builds these for me sizes the flue based on the size of the firebox openning. That way the draft is balanced. A flue will not draw well if it is too low, too large or too small. It can get even trickier for the interior one if the house is built tight or for the exterior one on a windy day. An air makeup supply might be a good idea for an interior fireplace in a tight new house.

   If you are currently framing and need an openning/header size, you are already ahead of yourself, because you needed a footer for the masonry mass to support it.

   If you intend to use prefab zero clearance instead of masonry and a false chimney chase, then you can google Majestic or Heatilator, select a unit, and download the spec PDF for sizing and clearances.

    

    

   Welcome to the
   Taunton University of Knowledge FHB Campus at Breaktime.
    where ...
   Excellence is its own reward!

1. 
   oops | Aug 08, 2013 02:39pm | #12

   Wd. Brrning. Firplaces

   Piffin. Question.  Would  you really need a damper for an outside fireplace?

1. 
   BossHog | Aug 29, 2013 05:02pm | #15

   Do you realize you're in a thread from 2006?

3. 
   Brian | Dec 27, 2006 04:31am | #4

   As an aside - if there is a way to keep the flue for the inside fireplace within the heated envelope of the house, it will draft much better. 

   I would recommend 2 flues inside 1 chimney.

   Happy New Year...

    

   Treat every person you meet like you will know them the rest of your life - you just might!
1. 
   Piffin | Dec 27, 2006 01:52pm | #5

   That is a good point but more impoortant in the north than in the south 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

1. 
   Brian | Dec 27, 2006 04:26pm | #6

   Point taken.  I should add that if you intend to use your chimney for actual heat, which is less common everywhere, and probably more so in the South.  I learned about Masonry heaters from a Canadian...

    Treat every person you meet like you will know them the rest of your life - you just might!

2. 
   basswood | Dec 27, 2006 05:15pm | #7

   Masonry chimneys on South facing exterior walls draft better too (due to solar heating). Edit to add: I believe Ben Franklin was a strong voice for chimneys on South walls. In this orientation, they will also be a solar heat sink in the winter (even when not in use) but will absorb less heat in the summer than a chimney on the East or West.

   Edited 12/27/2006 10:14 am ET by basswood

4. 
   DanH | Dec 27, 2006 05:19pm | #8

   Even though you'll "never use it", install gas pipe, or a raceway for the same, especially for the inside unit.

   People never lie so much as before an election, during a war, or after a hunt. --Otto von Bismarck
1. 
   build_one | Dec 27, 2006 07:47pm | #9

   So it sounds like a back to back version should not have any problem with downdrafting.  Any ballpark ideas on price? 

1. 
   Piffin | Dec 27, 2006 11:59pm | #10

   ;)I'll sit this one out... 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

5. 
   kpinkston9 | Aug 08, 2013 09:32am | #11

   back to back fireplaces

   I have read these comments from a few years ago and was wondering how it turned out?  I too would like to build a back to back fireplace for inside and outside, and am wondering how to go about it?  We want it to be wood burning on both sides (have a gas one already in another room).

6. 
   user-2819516 | Aug 29, 2013 02:40pm | #13

   Test

1. 
   calvin | Aug 29, 2013 03:28pm | #14

   Test?

   Test what?