I am putting up an old log house on a traditional foundation. I want a fireplace. I would like brick in front of the fireplace. My question is when i put in the 1st floor joists, what should i do to accomodate the brick?
thanks
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I think the house I saw with brick like that had plywood over the joists and then a mortar bed with the brick set in. I think then the rest of the floor had hardwood (later covered with carpet), but the brick stood proud of the hardwood--i.e., the joists weren't cut away to make room for the brick so it would be flush with the rest of the floor. I would think any cutting of the tops of joists (if indeed you were considering it) would weaken them just where they are supporting a heavier than normal load.
thanks for the info. Do you think i should double up the joists in that area?
Stew
I may have unintentionally steered you wrong by maybe misunderstanding what you were saying: I assumed (always dangerous) that you would naturally know to put a footing and foundation under a brick or masonry fireplace and was thinking you were just asking about a brick floor in front of it. Others got me thinking about my maybe not understanding. Anyway, Piffen's idea of extending the fireplace foundation (unless I'm not understanding him either!) to include the brick floor is a good one. You could also use deeper joists or more of them just where you plan to have brick and header that area off with doubled 2 X 10's or whatever will ne necessary for the load, and supporting those with posts or tying them into a main beam. The advantage of separate joists and headers is that the brick can be lower so it's flush with the surrounding floor. I guess I wouldn't want to take up a lot of basement area (if there is one) with a foundation for a brick floor that may not be all that heavy. Corballing (lots of labor) or perhaps angled brackets from the floor joists to the wall under the fireplace itself may work too. It all depends on how large the brick floor.
If its just a foot or so of brick by 3' long (something not too large), I still think just a "standard" wooden floor would work--but as you say, it might be a good idea to double the joists there or put them at 12" on-center instead of 16". It really depends on the load and how close to support below this will be. Just the brick floor load (with mortar bed) could be calculated and the joists sized accordingly from a table.
A question I have for Piffen is should "tarpaper" be put over the plywood and under the mortar bed? Or plastic sheet?
I apologize for not giving enough info on my brick question...so here goes. Yes, I know i need a slab at the base of the footer, that is in the plans and I am contracting that out. I also am not going to build the fireplace, I will hire someone.(I want a rumford? fireplace and have not found someone yet to do it) I am going to put the first floor joists and flooring in and thought i should try to plan ahead a little( not something i am very good at) The brick will be an extension of the hearth and would come ito the room 2 or 3 feet. That is what i wanted to support. Also, is there a thinner type brick that could be used for this purpose?
thanks for all your info! It is appreciated.
Stew
If you have'nt found a mason yet, you'd better scale the fireplace on your plans[ you do have plans?] before you frame.
I have'nt done alot of masonary FPs, but the ones I've seen....the hearth came up with the brick-work. ahh....what was the question ?
You need a foundation. A rumored is a masonry fireplace. Masonry needs a solid foundation. That's what I hate about profession. Some of the most important parts, get covered up. You pay for it, but you do not see all the work and planing that goes into it.
Yep, it can get prety complicated if you don't think ahead
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Nice round mud boards. Anybody shoud be able to to what you do. NOT!
Hunh?
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Can't use thin brick.
The hole in framing needs to be large enough for the hearth also. The hearth has to be non-combustable. A fire-resistant surface on an otherwise combustable assembly does not make it non-combustable. Supposing that after some time, if you had just put thin brick pavers on a wood subfloor, after some movement, the grout lossened and allowed cinders to settle through to smolder on that subfloor. Suppose that might be a problem?Add to that the fact that the wood and the masonry will move separatly, so it is more than likely that a crack would develope. The reason for the hearth is that hot cinders WILL migrate out. Standard hearth size is 18" front and 12" to side of the FP opening. Your local codes may require more. Size of openning and size of flue/chimney & height are related variables in FP design to have decent draw. so the whole thing is a matter of co-ordinated design. It is something you want to know before you frame. Planning ahead is good stuff.
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I found some shots of the same FP in progress. Paul is working from on the hearth slab extension ( with foam to make it comfortable) to build this. As I said earlier, there were six flues in thsi chimney. Three fireplaces were on this floor.
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Stew,
>>I know i need a slab at the base of the footer,
Uhm. . . What do you mean?
A footing is the lowest part of the structure, usually buried according to frost depth. Sometimes deeper according to soil engineers report.
A slab sits on top of the ground and acts like a floor.
You're saying that the floor is buried under the footing?!?!?!?
A rumsgord fireplace will weigh tons and it will only have a footprint of 12-20 sqft. It will need it's own massive footing. The footing can't be designed with out the completed fireplace design.
"Design from the bottom up, engineer from the top down." So, the first question is, "what kind of a chimney cap you want?" The last decision is, "The chimney footing must be L" x W" x D", with #R rebar, S" O.C., on F" of Engineered Fill compacted to C%."
After you got all that info, you can design your floor structure.
Ain't GCing fun?
SamT
>> The footing can't be designed with out the completed fireplace design.Well, it _can_ be, at the risk of wasting some resources. If you design for a worst case fireplace, you can then build any fireplace that size or smaller on the footing.
You trying to make this guy more confused?
Or ya just like being outrageously nitpicky?
Suppose he wants a bare bones Rumsford? Which can be a relatively light masonry fireplace.
Now, design a footing for a three story fireplace, 8'x15' on the main floor with a 6' deep hearth made from 8"-12" river rock. A 8'x6' on the second, and a 6'x4' on the third; three separate flues going to a chimney that is 12'x6' and rises 10' above the highest point on the roof.
All solid masonry.
On deep clay soil.
Waste some resources?
SamT
>> You trying to make this guy more confused?
>> Or ya just like being outrageously nitpicky?Yes.I got lazy. I wrote "design for the worst case" but what I really meant was "design for the upper end of the range of options the client is actually considering."I can easily imagine a situation where it would make sense to put several extra pounds of rebar and several extra cubic feet of concrete in the ground to keep the project moving. For example, suppose a client wants a fireplace in the living room but isn't sure yet about the one in the second floor master bedroom. Much better to design and build the footing for both, even if the second FP is never built, than to build the minimum footing and then have to retrofit it to support the second FP.
neither. My masons will not build a fireplace with the masonry in contact with the framing. Code and liability issues. Also, the masonry will move differently than the wood frame. I do have to correct the earlier statement about suport under. You got me to remembering. This particular job had suix flues in one chimnney so there was plenty of mass as it was. The hearths were supported via a poured corble. The way that was dione was the CMU base under the main chimney and fireplaces was brought up in cellar to about 10" below finished floor, then all the hearth areas were surronded with foam on the sides, 1/1/2" or 2" thick. a plywood floor for the concrete form was extended to the front of hearth framing , made for removal from under. Plenty of steel went into the form and the mason's hod boy got to work a little harder that day mixing. later, when the ply support form came out from under, there was no contact between the crete shelf and the framing.
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Stew, I hope you're reading what Piffin and the others are saying; thay know a lot more, and a lot more correctly LO than I do! The fireplace I saw did have brick on the plywood, but obviously that is NOT the way to do it. It had cracked and we ended up taking the hearth out. And with a fireplace, with the weight and fire danger, it's no place to skimp.
I believe the name for the fireplace type is "Rumford [no 's' in the name], developed by Sir Benjamin Thompson, also known as Count Rumford. The reason I know is I just finished reading a book called The Distinctive Home that had a sidebar about that kind of fireplace. I recommend this book, especially for people who are designing their own home. Books by Susanka are good too.
If your fireplace is a masonry fireplace, you need to pour a footing and either concrete or concrete block up to the the starting elevation.
If it's some other design, like a gas f/p or woodstove, you can crowd your joists (like 8" or 12" centers under the unit and the hearth.
Might be good to consult some span tables after determining what the weight of your completed unit will be across its footprint.
So far you have not povided info as to whether you are building a brick fireplace or using a metal prefab and just want a brick hearth extension for show and maybe a facade also - what about the chimney too? And are you looking for a raised hearth of a fush set one?
So far you question reads like, "How big should my airplane wing be?" What kind of airplane do you want? How far will you expect to fly it?
In this photo, the framing has NO connection to the brick. There is a mass of block CMUs in the cellar and the floor frameing is headered off with an inch or two of free play. The wood floor is all that connects directly
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yeah, I know - milling b shows tha masonry mass off to the right behind a white box...
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A masonry fireplace has its own foundation, you can't just rest it on joists.
If you have some self-standing units, as Wormdrive said depends on the weight.
Those zero clearance gas fireplaces are not that heavy so you may not have to do anything to the joists. If you have a large cast iron wood stove you may have to crowd or double up the joists.