Smoking Fireplace - Masonry - Contractor Talk

Smoking Fireplace

 
Thread Tools Search this Thread Display Modes
Old 04-30-2010, 06:50 PM   #1
Pro
 
artisanstone's Avatar
 
Trade: Stonemasonry
Join Date: Nov 2007
Location: upstate, sc
Posts: 663
Rewards Points: 662

Smoking Fireplace


Maybe you guys can give me some perspective on this. I built an outdoor fireplace a few weeks ago. The homeowners call me today to say that it does not draft. Of course I say "no problem, I stand behind my work, I'll be there tomorrow, etc". I'm rehearsing possible scenarios in my head about why this would happen. I'm hoping that the poor people just don't know how to build a fire, but

The facts:
-Firebox is 36x24 or so.
-Flue liner is 16x16 (Big because outdoor fireplaces are not tall....maybe this is the problem).
-Chimney height is about 6' above firebox floor, plus a 2' chimney pot.
-Fireplace is built to a plan by the BIA. They call it a Rumford, but it really isn't. Only modifications are, no damper, shorter, and arched opening.

Suspected problems:
-Fireplace is at the bottom of a very steep partially wooded lot. 3+ story house absolutely looms above. House is probably 150' away and 60' higher at the top.
-Chimney pot is considerably smaller than the flue. Homeowners already had it (antique). It measures about 13x13.
-I've never built a fireplace to this plan before. It was chosen to reduce cost.

I'll post more if I think of more. I realize that most of you won't be around on Friday evening, but TIA.
artisanstone is offline  

Warning: The topics covered on this site include activities in which there exists the potential for serious injury or death. ContractorTalk.com DOES NOT guarantee the accuracy or completeness of any information contained on this site. Always use proper safety precaution and reference reliable outside sources before attempting any construction or remodeling task!

   

Advertisement

 

Old 04-30-2010, 07:57 PM   #2
Capra aegagrus

 
Tinstaafl's Avatar
 
Trade: Remodeler
Join Date: Jan 2008
Location: Central Pennsylvania
Posts: 23,405
Rewards Points: 86

Re: Smoking Fireplace


Quote:
Originally Posted by artisanstone View Post
-Fireplace is built to a plan by the BIA. They call it a Rumford, but it really isn't. Only modifications are, no damper, shorter, and arched opening.
What's shorter; the firebox or the flue? A smaller firebox shouldn't hurt, though the arched opening could affect the pattern of airflow--i.e., air that would normally enter lower and closer to the fuel would come in a bit higher and not fan the fire quite as much.

I could be wrong, but I doubt the location/surroundings as described play much of a role. I've built many open fires in just about every type of locale, and none have affected their efficiency much at all.

Quote:
-Chimney pot is considerably smaller than the flue. Homeowners already had it (antique). It measures about 13x13.
That's a definite eyebrow-raiser. Obviously, that's going to choke the draft down a bit. I wouldn't expect it to be an extravagant amount, though.

Other thoughts...

How many fires have they tried? Some days, the combination of barometric pressure, temperature, humidity and bad karma make a wood fire burn frustratingly poorly even in a well-designed and normally well-functioning setup. Maybe try again after a significant change in the weather.

What fuel are they using? Take some good dry oak with you and try that out.

Are they burning on the floor of the firebox, or an elevated grate? Big difference there.

But I agree, there's probably a good chance they just don't know how to build a fire--or maybe what "good draft" is.

And for typing all this after a long day of shingling, I demand a pic!

Advertisement

Tinstaafl is offline  
Old 04-30-2010, 08:33 PM   #3
Pro
 
Tscarborough's Avatar
 
Trade: Monkey Scratching Cat Herder
Join Date: Feb 2006
Location: Austin
Posts: 6,346
Rewards Points: 1,460

Re: Smoking Fireplace


The pot shouldn't be a problem, as that is the size needed for a 36". The height of the chimney could be an issue but probably isn't. The placement sounds good. What is the depth and did you use a Rumford style throat and smoke chamber? Is there a smoke ledge?
Tscarborough is offline  
Sponsored Links
Advertisement
 
Old 05-01-2010, 07:23 AM   #4
Pro
 
dbrons's Avatar
 
Trade: Masonry
Join Date: Apr 2010
Location: Carlsbad CA
Posts: 406
Rewards Points: 608

Re: Smoking Fireplace


yes, I agree. Often, the problem lies in what's between the firebox, and the first flue.

I almost always use a damper on an outdoor fireplace, but with or without, you need a throat above the lintel, and a chamber shaped kinda like a funnel to direct the smoke into the flue.

Dave
dbrons is offline  
Old 05-01-2010, 07:42 AM   #5
Pro
 
artisanstone's Avatar
 
Trade: Stonemasonry
Join Date: Nov 2007
Location: upstate, sc
Posts: 663
Rewards Points: 662

Re: Smoking Fireplace


The throat and smoke chamber are built to this plan. http://docs.google.com/viewer?a=v&q=...MA1oe14kfvadGA

Smoke chamber is made with two cut-down liners. There is two feet of chimney above the smoke chamber, and then the pot on top.

They've only tried burning it twice. They seem to be a little smoke sensitive, as this was built to replace a previous fire-pit because it was too smoky.
artisanstone is offline  
Old 05-01-2010, 08:03 AM   #6
Pro
 
jomama's Avatar
 
Trade: Concrete & masonry
Join Date: Oct 2008
Location: Wisconsin
Posts: 899
Rewards Points: 170

Re: Smoking Fireplace


Two things I notice from the link:

- The smoke chamber is only 12" high, so your only at about 4-5 feet above the firebox. Could be a tad short for this site. I normally would cut the SC a full 2' high if I was making it myself.

- You missed the detail in the drawing for the gas log set. Once you install that, all smoking problems will vanish.

Seriously now, I have this problem at home occaisionally, as the opening of mine is facing West, to prevailing wind. Good, dry wood is critical, as well as burning upright or "tee-pee" style. When burning that way, you'll be suprised how fast the smoke rises.

Good luck.
jomama is offline  
Old 05-01-2010, 08:05 AM   #7
Pro
 
dbrons's Avatar
 
Trade: Masonry
Join Date: Apr 2010
Location: Carlsbad CA
Posts: 406
Rewards Points: 608

Re: Smoking Fireplace


Thanks for showing the design. It looks real official, but frankly, I wouldn't trust that design.

The throat looks fine, though with an arch you would have to have it extend from the arches highest point, not from the low points.

The design has no smoke chamber - the flue sits right down on the damper. That's not good, and without the damper to at least funnel the smoke, you probably have too abrupt a transition into the flue. That, and I wouldn't really trust how shallow it is either, but that may just be me. I know a lot of people use the Rumfod design, but I always modify them and make them deeper.

I'm not sure how to suggest a fix. You could try removing the pot and replacing it with one or two flue pipes stacked up there dry, to see if that helps. You could raise the floor of the firebox with another layer of firebricks, or lower the arch.

Dave

PS Joe makes a good point - this is suggested for a gas log, not wood.

PPS OK, I do see now that this is a kit with a smoke chamber, I had just looked at the side view and didn't notice.

Still, as Joe suggested, when you build one with brick, it's usually at least 2' tall.

Last edited by dbrons; 05-01-2010 at 08:15 AM.
dbrons is offline  
Old 05-01-2010, 09:25 AM   #8
Pro
 
Tscarborough's Avatar
 
Trade: Monkey Scratching Cat Herder
Join Date: Feb 2006
Location: Austin
Posts: 6,346
Rewards Points: 1,460

Re: Smoking Fireplace


That is not a Rumford other than the depth. My understanding of the design, based on the Count's own words are that the throat cross section is critical when building that shallow. An arched opening will make it even more critical.

I would just show them how to light a slow starting fire to warm the flues and expect some smoking since it is outside.
Tscarborough is offline  
Old 05-01-2010, 12:21 PM   #9
Stonemason
 
bytor's Avatar
 
Trade: masonry
Join Date: Jan 2010
Location: Ontario
Posts: 647
Rewards Points: 638

Re: Smoking Fireplace


dbrons suggestion is a good one...to remove the chimney pot and dry stack a couple (or three) of flue liners up to see if there would be any benefit to additional chimney height. We've run into this problem on occasion, and it's surprising what a little extra chimney height can do....
bytor is offline  
Old 05-01-2010, 04:36 PM   #10
Pro
 
jvcstone's Avatar
 
Trade: Masonry / architectural stone carving
Join Date: Apr 2005
Location: Central Texas
Posts: 365
Rewards Points: 250

Re: Smoking Fireplace


One other thing to consider--a good draw depends on a temperature differential between the air feeding the fire, and the air surrounding the flue top. That's not often the situation with outdoor fireplaces--especially if it is being used on a relatively warm night. I've built several outdoor fireplaces, but always let the client know that there might be draw problems some of the time. and explained why. Thus, never a call back.

JVC
__________________
John VanCamp
www.jvcstoneworks.com
jvcstone is offline  
Old 05-01-2010, 05:10 PM   #11
Chief outhouse engineer
 
dakzaag's Avatar
 
Trade: mason
Join Date: Jan 2009
Location: NW Indiana
Posts: 1,418
Rewards Points: 786

Re: Smoking Fireplace


This thread is worthless without pics.

With pics, it could be one of the most informative masonry pics this site has ever seen.

Lets see some pics
__________________
D K & Sons
The maintenance schedule for brick
1. Stand back and say "man that looks nice!"
2. Repeat as often as needed.
dakzaag is offline  
Old 05-01-2010, 05:40 PM   #12
Pro
 
artisanstone's Avatar
 
Trade: Stonemasonry
Join Date: Nov 2007
Location: upstate, sc
Posts: 663
Rewards Points: 662

Re: Smoking Fireplace


OK, I went to look at it today. (Sorry, no pics as of yet.) I burned a fire in it, and it draws surprisingly well! The problem is that when the wind blows, it will blow some smoke out of the firebox. Meanwhile, it is still streaming out of the flue. I put my hand above the chimney pot (climbed up it ) and there is good velocity of exhaust up there. The other thing I noticed is that the smoke, after leaving the flue, was going back down to the ground and flowing along it. This makes me suspect air pressure problems as discussed before.

I saw a couple of things I could have done better, and these will be fixed. The breast could be more streamlined in shape, and I may add a half-brick course around the immediate firebox opening to try to reduce some wind effects.

I think that the owners may be hypersensitive to smoke, and I will suggest a glass door as the only complete solution. Thanks for the advice, I'll let you know how it works out, and I'll get some pictures.
artisanstone is offline  
Old 05-01-2010, 05:57 PM   #13
Handle It!
 
MALCO.New.York's Avatar
 
Trade: Everything The Union Guys Do Not Want To Do
Join Date: Feb 2008
Location: Brooklyn, NY ~ Haverford, PA
Posts: 9,588
Rewards Points: 2,000

Re: Smoking Fireplace


As with many open flow systems, one may need to preheat the Stack Vent. Light a wad of Kindling Paper, hold into Flue, allow there to begin an up-draft! Should rectify the situation.
__________________
Something to One may be Nothing to another!

Ultimate Wisdom---------
http://www.youtube.com/watch?v=OW-cnizLDEE
MALCO.New.York is offline  
Old 05-02-2010, 07:43 PM   #14
Pro
 
cdkyle's Avatar
 
Trade: Concrete & General Construction
Join Date: Jul 2009
Location: The Heartland of the United States of America
Posts: 710
Rewards Points: 576

Re: Smoking Fireplace


Lintel or arch opening is probably too high off floor of firebox. Lower the lintel or install glass doors. On that size box, the height of lintel should not exceed 24". Seen many set at 27" and above, and they have the same problem.

Advertisement

cdkyle is offline  


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Heating new Family Room w/ gas fireplace? Slowtrawl HVAC 56 06-20-2010 05:50 AM
FIREPLACE guys.. need help on vent stack routing Little Carpentry 10 03-07-2010 11:17 PM
Does fireplace opening in block wall opening need support? Square-One Masonry 6 11-22-2008 02:31 AM
Masonry chimney on new EPA fireplace? GregWCIL Masonry 8 10-28-2008 08:51 PM
Does fireplace opening in block wall opening need support? Square-One Construction 1 02-28-2006 01:59 AM

Join Now... It's Fast and FREE!

I am a professional contractor
I am a DIY Homeowner
Drywall Talk is for
PROFESSIONAL CONTRACTORS ONLY!

At DrywallTalk.com we cater exlusivly to professional contractors who make their living as a contractor. Knowing that many homeowners and DIYers are looking for a community to call home, we've created www.DIYChatroom.com DIY Chatroom is full of helpful advices and perfect for DIY homeowners.

Redirecing in 10 seconds
No Thanks
terms of service

Already Have an Account?