Forums | Home Repair | Home Improvement | Painting | Interior Decorating | Remodeling | Landscaping


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Building & Construction

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 11-25-2009, 06:06 PM   #1
Newbie
 
Join Date: May 2009
Location: Surprise, Arizona
Posts: 20
Share |
Exclamation

Fireplace dimensions???


I am building a natural gas outdoor fireplace. I have constructed the firebox pad that is 41" wide by 27" deep by 4" thick (see photo). I have planned to use a 30" log set. I have some questions regarding the construction of the firebox.

1. How do I determine the width, height, and depth of the firebox opening for optimal performance?

2. At what angle should I angle the side walls of the firebox for maximum heat radiation (in other words, what should the back width be)?

3. Do I need to design the throat like a traditional wood burning fireplace, or is this less important for a natural gas outdoor fireplace?

4. How do I determine the flue size? Is it based on the firebox opening?

5. How do I determine the height of the chimney?

Thanks
Attached Thumbnails
Fireplace dimensions???-img_1760.jpg  

Last edited by figs; 12-05-2009 at 12:07 PM.
figs is offline   Reply With Quote
Old 11-25-2009, 11:23 PM   #2
Registered User
 
Termite's Avatar
 
Join Date: Apr 2008
Posts: 6,520
Default

Fireplace dimensions???


I'd suggest that you go to City hall or the library and look at a copy of the international residential code, or your area's adopted code. There's a chapter devoted to chimneys and fireplaces and the dimensional requirements for them. It has some good diagrams. There are waaaaay too many variables for me to answer your questions online. There are a lot of construction details that make a big difference and are required by the code as well (parging the throat corbeling for example).
Termite is offline   Reply With Quote
Old 11-26-2009, 12:27 AM   #3
Newbie
 
Join Date: May 2009
Location: Surprise, Arizona
Posts: 20
Question

Fireplace dimensions???


I have been looking over this link to the IRC (http://www.rumford.com/code/IRC06.html). It does state a lot of minimum dimensions, but it really does not talk about fireplace science. I guess what I'm looking for is something that explains how to get the maximum heat radiation from the firebox.

Are natural gas outdoor fireplaces constructed the same as wood burning fireplaces? I live in Arizona, so most of the fireplaces are all inserts. The masonry ones that I have been shown by contractors don't seem to follow any codes in the IRC.

The first photo is an example of a fireplace that was shown to me by a local contractor. The chimney has exposed CMU.

The second photo is an example of a fireplace that has exposed backerboard:

From what I have seen, this seems to be the norm for outdoor fireplace construction. This sure doesn't look like to correct way to build a fireplace!
Attached Thumbnails
Fireplace dimensions???-img_1712.jpg   Fireplace dimensions???-img_1698.jpg  

Last edited by figs; 12-05-2009 at 12:13 PM.
figs is offline   Reply With Quote
Old 11-26-2009, 12:21 PM   #4
Member
 
Join Date: Mar 2007
Location: Long Island, NY
Posts: 9,519
Default

Fireplace dimensions???


Try this for a plan.
http://en.wikipedia.org/wiki/Rumford_fireplace
Ron
Ron6519 is offline   Reply With Quote
Old 11-27-2009, 03:13 PM   #5
Member
 
Join Date: Jun 2009
Location: Somerset, England
Posts: 665
Default

Fireplace dimensions???


These might help with the dimensions.
Fireplace dimensions???-phpdpqwajpm.jpg

Fireplace dimensions???-phpfcdw6lpm.jpg
stuart45 is offline   Reply With Quote
Old 11-28-2009, 08:30 AM   #6
Concrete & Masonry
 
Join Date: Nov 2008
Location: Wisconsin
Posts: 2,556
Default

Fireplace dimensions???


Quote:
Originally Posted by figs View Post
I am building a natural gas outdoor fireplace. I have constructed the firebox pad that is 41" wide by 27" deep by 4" thick (http://www.diychatroom.com/members/f...-firebox-base/). I have planned to use a 30" log set. I have some questions regarding the construction of the firebox.

1. How do I determine the width, height, and depth of the firebox opening for optimal performance?

You're looking at the right sight, here is all the dimensions you need for a Rumford style firebox: http://www.rumford.com/classicflyerplan.html

2. At what angle should I angle the side walls of the firebox for maximum heat radiation (in other words, what should the back width be)?

All dimensions are listed above, sides are 45* on a Rumford leaving a very narrow, tall back wall.

3. Do I need to design the throat like a traditional wood burning fireplace, or is this less important for a natural gas outdoor fireplace?

I would "guess" that it's less important outside w/ gas, but I think I would at least try to choke the throat down a little anyways.

4. How do I determine the flue size? Is it based on the firebox opening?

Yes, Rumfords generally use larger flues due to their taller opening, which equals more cross section vs. the same width in a conventional FP.

5. How do I determine the height of the chimney?

For a free standing, the taller the better. It's honestly kind of a trial & error issue with an exterior wood burning, probably far more of an asthetic decision with a gas burner.

Thanks
Make sure to post some process/finished pics!
jomama45 is online now   Reply With Quote
Old 12-05-2009, 01:44 PM   #7
Newbie
 
Join Date: May 2009
Location: Surprise, Arizona
Posts: 20
Question

Fireplace dimensions???


Thanks for the replies!

I considered building a Rumford, but they don't seem to accommodate large gas log sets very well. The gas log set that I have requires a firebox with these minimum dimensions: front width: 36", back width: 27", depth: 18", height: 18". A Rumford with a 42" wide opening (roughly the width of my firebox base) only has a depth of 15" and a back width of 15". I did find some technical information on The Brick Industry site (http://www.gobrick.com/html/frmset_thnt.htm). On the left hand side, scroll down to Technical Note 19 - Residential Fireplaces. I was thinking about designing the fireplace to be a hybrid between a Rumford and a traditional fireplace (the fireplaces listed on The Brick Industry site above). So my design would be as follows:

opening width: 42"
opening height: 32"
depth: 18" - 20"
rear width: 29"
I would not angle the back wall of the firebox, so it would be in Rumford style.
I also would construct the throat like a Rumford.

Do you think that mixing these designs will work, or should I rethink my design? Suggestions?

jomama45, I have read some of your other posts, and it appears that you are also building a fireplace. Do you have any pictures of it?

I have posted some pictures of my outdoor gas fireplace so far (http://www.diychatroom.com/members/f...gas-fireplace/).

Thanks!

Last edited by figs; 12-06-2009 at 09:40 AM.
figs is offline   Reply With Quote
Old 12-07-2009, 02:12 PM   #8
Concrete & Masonry
 
Join Date: Nov 2008
Location: Wisconsin
Posts: 2,556
Default

Fireplace dimensions???


Figs, I'm actually a mason by trade. I've done quite a few Rumfords in my life. Mostly interior, but also 2 outside FP's, one of which was at my own home this summer. Just for the record, I would never install any natural (wood burning) masonry FP that wasn't a Rumford due to many personal reasons. Mostly because : They are fairly easy & consistent, work very well when burning, & are more asthetically pleasing IMO.

For your situation, I see no reason why you couldn't blend a Rumford & conventional style FP together. Far less concerns with draft design, etc. with a gas log vs. real wood fuel, especially outside.

The benefit to the Rumford shallower & taller box & 45* walls is that it radiates heat very well out of the firebox, far better than a conventional IMO. You can adjust all the dimensions according to fit your log set, just keep the design & ideals in the back of your mind.

I would sway away from the cement backerboard if it was me. I don't see it last very long, & it would suck to put all this work into a project just for something like that to prematurely fail. Trust me, it's no fun working inside of a firebox AFTER it's built! Normally I use the Buckley Rumford throat & smoke chamber, but on mine I experimented (cheated) a little to save some cash. I recycled a section of concrete culvert that was removed from my driveway last year for the throat. I plastered the concrete culvert section as well with the same refractory cement (Heat Stop II) to help guard against heat damage. I also made my own smoke chamber out of 2 standard flues, fairly easy.

I'll attatch a few progress pics for now, maybe even a finished pic if/when it stops snowing out!

BTW, very nice work on your project so far! Far more involved than what I was willing to do at home.

Fireplace dimensions???-dsc00886r.jpg

Fireplace dimensions???-dsc00889r.jpg

Fireplace dimensions???-dsc00890r.jpg
jomama45 is online now   Reply With Quote
The Following User Says Thank You to jomama45 For This Useful Post:
oliver8 (09-27-2011)
Old 12-08-2009, 06:29 AM   #9
Member
 
Join Date: Jun 2009
Location: Somerset, England
Posts: 665
Default

Fireplace dimensions???


Looks a great job jomama. I've never seen an outside fire place over here. Might have a go at building one next year. Are those Stabilla levels? I thought you all used wooden ones because they got too hot in the summer. We don't have that problem as it rained nearly every day this year.
stuart45 is offline   Reply With Quote
Old 12-08-2009, 07:44 AM   #10
Concrete & Masonry
 
Join Date: Nov 2008
Location: Wisconsin
Posts: 2,556
Default

Fireplace dimensions???


Quote:
Originally Posted by stuart45 View Post
Looks a great job jomama. I've never seen an outside fire place over here. Might have a go at building one next year. Are those Stabilla levels? I thought you all used wooden ones because they got too hot in the summer. We don't have that problem as it rained nearly every day this year.

Thanks Stu. The one level is indeed a Stabila, the other just a cheap aluminum that gets abused like the Stabila, but definately shows it. I was at a huge concrete/masonry convention in Las Vegas 10+ years ago when I first saw their mason levels. When the rep was pounding on the level vial w/ a hammer & it didn't break, I knew that was a level for me! Of course I "needed" to prove the indestructable vial to my co-workers & broke it on the second hit! Luckily, they waurenteed it.

As for the wood, I cant believe it would have to do with the heat, especially in Wisconsin. Everyone here used wood at one time, but many have shifted to aluminim thru the years. I would imagine the ones still using wood do so because they still feel aluminim are inferior? As for me, I cant see myself buying another wood level in my lifetime.
jomama45 is online now   Reply With Quote
Old 12-08-2009, 07:56 AM   #11
Newbie
 
Join Date: May 2009
Location: Surprise, Arizona
Posts: 20
Thumbs up

Fireplace dimensions???


jomama45,

Nice work! It looks great!

I'm not a mason. In fact, this is the first masonry project that I have ever built, so it's taking me forever to complete it.

I'm going to face the fireplace in cultured veneer stone. I was told that I don't need to use wall ties. Is that correct?

I'm sure that I will have a lot more questions as my project evolves!

Thanks for all of the help!
figs is offline   Reply With Quote
Old 12-08-2009, 08:08 AM   #12
Concrete & Masonry
 
Join Date: Nov 2008
Location: Wisconsin
Posts: 2,556
Default

Fireplace dimensions???


That is correct figs, no wall ties necessary with any cultured/thin stone or brick. Simply adhered to the CMU (block) with conventional mortar.

I would suggest "padding" out the face of the FP 2-4" additional with CMU & using cultured stone corners on the return of the firebox. This will give a far more realistic look & better scale IMO. It will also give you a little more room inside for the logset.

Best of luck, I'm looking forward to more pics.
jomama45 is online now   Reply With Quote
Old 09-27-2011, 11:58 PM   #13
Newbie
 
Join Date: Sep 2011
Location: WI
Posts: 1
Default

Fireplace dimensions???


Jomama,
I had similar questions, related to fireplace design. Thanks for your post and pictures.
I'm in the process of building a home in Appleton, and am trying to figure out how to create an outdoor fireplace.
I note that you are in WI, and also a mason by trade. Are you near enough to Appleton to want to take a look at the job? My builder has only offered landscaper-type-people to help with figuring out the fireplace/patio area.

Thanks,
Oliver
Appleton, WI
oliver8 is offline   Reply With Quote
Old 09-29-2011, 08:52 PM   #14
Concrete & Masonry
 
Join Date: Nov 2008
Location: Wisconsin
Posts: 2,556
Default

Fireplace dimensions???


Quote:
Originally Posted by oliver8 View Post
Jomama,
I had similar questions, related to fireplace design. Thanks for your post and pictures.
I'm in the process of building a home in Appleton, and am trying to figure out how to create an outdoor fireplace.
I note that you are in WI, and also a mason by trade. Are you near enough to Appleton to want to take a look at the job? My builder has only offered landscaper-type-people to help with figuring out the fireplace/patio area.

Thanks,
Oliver
Appleton, WI


Oliver, no, I'm sorry, I'm alot closer to Milwaukee, and Appleton is too far for me. If I were you, I'd also look for a mason as well before falling for whatever it is the landscaper is going to sell you. Three suggestions I can give you:

1) Check with your local brick/masonry yards (Zoll, Hauckers, Gagne, County Materials are all in GB, but I prefer Buechel Stone in FDL) for a few names of reputuable masons. If you get the same name a few times, you've probably found a very competant mason.......

2) Check rumford d o t com for a list of masons, there will likely be at least one in your area. This is a manufactures site that I use frequently, and it's a very simple, easy masonry FP, well at least for a mason.

3) You can try to PM another member here who goes by "6stringmason" that's certainly closer to your locale. Ne may be able to help you, or guide you in a better direction. The only problem is you don't have the min. 10 posts (Ithink) to recieve PM privledges yet, so post away........
jomama45 is online now   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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
new opening in fireplace? burningbaal Remodeling 3 10-11-2009 01:18 PM
New project: removal of old fireplace-replace with a new fireplace! MrShadetree0222 Building & Construction 14 10-16-2008 06:12 PM
temper glass for fireplace mantel shelf sil Interior Decorating 3 02-13-2008 08:10 PM
Possible to build direct-vent fireplace? DIYerself General DIY Discussions 3 12-22-2007 10:07 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.