Replies

1. 
   OneofmanyBobs | Nov 14, 2003 01:02am | #1

   An engineer is an absolute must in this situation.  23 feet is very long for a header.  There has to be adequate bearing on each end and the foundation needs to be evaluated as well.  Also any bearing walls above, point loads, roof loads, etc.  It might require piers.  A header that long in wood will be huge.  You'll most likely need steel.  The last one I did which was only 16 feet long needed to be an 8 by 12 laminated beam.  And, it depends a lot on the specific situation.  Talk to an engineer.  I think you may end up with a post in the middle.

2. 
   steve | Nov 14, 2003 01:08am | #2

   thats one big beam and span

   you definitely need professional advice with an engineers stamp on the plans

   and how would you ever get something that big and long into the house, let alone up onto the support posts

   personally i wouldnt even try, especially in a 100 year old house

   caulking is not a piece of trim

3. 
   HammerHarry | Nov 14, 2003 03:44am | #3

   That's not a header, that's a steel beam.  And a fairly big one, maybe 6 x 16??  That's a GUESS, don't believe it.  Find an engineer who knows what he's doing, and pay him what he asks.  Or cross your fingers and run like H377....

1. 
   ckeli | Nov 14, 2003 04:32am | #4

   why not a few 2x6's?  isn't that the way they did it in the "old days"?  my parent's house would pass for that!!

2. 
   Piffin | Nov 14, 2003 04:34am | #5

   It surely would need to be a steel beam to span that distance with no interim support. If there is a floor above in adition to the roof, I don't doubt that the engineer would be specing something heavier than you mention. I know you said it's only a guess. Mine too..

   Excellence is its own reward!

3. 
   JohnSprung | Nov 14, 2003 10:46pm | #16

   6 x 16 sounds very light to me, they don't even have it in the brief table in the Parker/Ambrose book.

   If we use 2000lbs/ft as a ballpark number for a girder in residential construction, we're trying to hold up 46 kip here.  From the table, W 14 x 48 or W 16 x 45 are closer to the mark.  The steel would come in a little north of half a ton.

   -- J.S.

1. 
   HammerHarry | Nov 15, 2003 05:49am | #21

   By the way, when I threw out the 6x16 number, I was estimating the width and depth; I deliberately used not-correct terminology, so that no one would assume this was anywhere near a proper guesstimate.  So that's why I didn't use a W figure, as it should be (okay, a W16xsomething), cause my steel tables are at the office).   And I'm a mech, not a civil, anyway.

4. 
   BossHog | Nov 14, 2003 04:36am | #6

   I don't know that you need an engineer, but you definitely need someone to come out and look at it who's knowledgeable in structural design. The others are right in saying that 23' is a heck of a long span.

   Have you considered what you're going to do with the point loads at each end of the beam? If you're carrying much weight, you could have a heck of a reaction at each end, which might require a post and concrete footing.

   You feel stuck with your debt if you can't budge it.

1. 
   VaTom | Nov 14, 2003 04:51am | #7

   Have you considered what you're going to do with the point loads at each end of the beam? If you're carrying much weight, you could have a heck of a reaction at each end, which might require a post and concrete footing.

   Bingo!  We do that span easily with far higher loads using steel bar joists.  But you've gotta have something substantial to set the ends on.  Depending on load, a 12" or 14" tall bar joist would handle it and be light enough to place manually, around 150 lbs.PAHS Designer/Builder- Bury it!

1. 
   Piffin | Nov 14, 2003 05:09am | #9

   That's a new one for me.What is a bar joist?.

   Excellence is its own reward!

1. 
   Boxduh | Nov 14, 2003 06:31am | #10

   Bar joists are open-web steel members, with a pair of continuous angles for top and bottom flanges, and a linked "W" array of bars welded between them.  Imagine a light steel truss, about 16 or 18 inches deep.  Used everywhere in light commercial construction, typically for flat-roof structures.

   View Image

   Edited 11/13/2003 10:44:39 PM ET by Mr. Micro

1. 
   VaTom | Nov 14, 2003 03:14pm | #11

   Imagine a light steel truss, about 16 or 18 inches deep.  Used everywhere in light commercial construction, typically for flat-roof structures.

   Great illustration.  Mine are typically a bit taller, more like 3', but I'm not dealing with normal housing loads.  300 psf takes a little more steel when the spans get lengthy, like 40' last time.

   Used commercially all the time due to low cost.  Same reason I use them.  The published tables tell you what you need, without paying for additional engineering if you know what your Total and Live load is.

   PAHS Designer/Builder- Bury it!

   Edited 11/14/2003 7:32:18 AM ET by VaTom

2. 
   Boxduh | Nov 15, 2003 12:13am | #17

   Actually, a bar joist is a contest, held in a large barroom, between mounted contestants, wearing armor (horses, too), in which the two run at each other, full tilt, carrying loinces.  I don't know what those are, but I think they are long pointed sticks.

1. 
   Piffin | Nov 15, 2003 02:52am | #18

   If loinces are long pointed sticks that proceed out of one's loins, it must be a gay bar, and I'll stay away from bar joists, Thank you..

   Excellence is its own reward!

2. 
   Boxduh | Nov 15, 2003 04:47am | #20

   Does one use a stud finder to locate loinces?

3. 
   HammerHarry | Nov 15, 2003 05:50am | #22

   And a big "barrroooom" is usually heard in the mens room of a big bar room....

2. 
   archyII | Nov 15, 2003 02:59am | #19

   I have never heard of bar joist being used as headers.  Floor and roof framing, but not headers.  Typically the bottom cord must be braced.  Bar joist are pretty flexible side ways.  You would need to run steel angles from the bottom cord to the deck or side walls to brace them. This guy needs an engineer to study the load path.  Did a project several years ago where new foundation walls/piers were needed to support the new loads.

1. 
   VaTom | Nov 16, 2003 11:38pm | #23

   I have never heard of bar joist being used as headers.  Floor and roof framing, but not headers. 

   Apparently you've never seen bar joists sitting on bar joists.  As for lateral bracing, yes, usually every 12' or so.  But it wouldn't be difficult to apply within whatever would cover the the joist.  Biggest problems occur with the required height of the bar joist/beam.

   The engineers I've hired, 3 different ones, did little more than read bar joist tables.  Not very difficult to understand.  The lateral bracing requirements come from the bar joist plant.  And they're just following industry standards.  Bearing in mind that 1/360th of the span is the approximate deflection due to allowed live load.  I got that directly from the bar joist table, not from any engineer.  And sometimes it makes a big difference, particularly with large spans.  40' is 1.33"! 

   Our local building department officials now agree that the engineering I have for bar joist support is adequate.  Even they have learned to read the bar joist tables, which I have to supply, to approve my plans.  Not very complicated.

   That's the beauty of bar joists.  It's been standardized.  Lots of applications and they work, inexpensively.  As I mentioned, and you found out, what holds them up can be considerably more difficult.   PAHS Designer/Builder- Bury it!

1. 
   archyII | Nov 17, 2003 04:03am | #24

   "Apparently you've never seen bar joists sitting on bar joists".  Nope, never saw this.  Does not mean it can't happen.  I've seen bar joist on steel beams, bar joists on cmu, even bar joist on wood beams but never on another bar joist.  Bar joists and point loads do not seem to like each other.  As for a header I would be concerned that the bar joist was properly braced for this application verses standard bracing for a roof or a floor.

2. 
   SamT | Nov 17, 2003 05:36am | #25

   NO, but I've seen barflys hanging around under bar joists.

   SamT

   "You will do me the justice to remember that I have always strenuously supported the right of every man to his opinion, however different that opinion may be to mine. He who denies to another this right, makes a slave of himself to his present opinion, because he precludes himself the right of changing it."   Thomas Paine

3. 
   VaTom | Nov 17, 2003 06:08am | #26

   Here too.  Ain't it great?  But what were you doing there?PAHS Designer/Builder- Bury it!

4. 
   SamT | Nov 17, 2003 06:25pm | #27

   just buzzin' around.

   SamT

   "You will do me the justice to remember that I have always strenuously supported the right of every man to his opinion, however different that opinion may be to mine. He who denies to another this right, makes a slave of himself to his present opinion, because he precludes himself the right of changing it."   Thomas Paine

5. 
   hammer1 | Nov 14, 2003 04:51am | #8

   We routinely span 24' to carry finished second floors over garages and for carrying beams. The steel supplier has an engineering staff that will help to calculate a suitable beam for your application. This is not a DIY project.

6. 
   Framer | Nov 14, 2003 03:43pm | #12

   Do the right thing and call an Architect or Engineer. There's absolutley no way anyone can tell you what you need for a 23' span without seeing your house, where this opening is going what it's carrying above, what size the beams are above and the span. Is 23' the width of your house, is it a back wall, center bearing partion wall, if so does the 23' land in the middle of the house, if so what's your girder in the basement and is there footings for a column to support the beam.

   There's a million different scenarios. I framing an addition right now where we used a 12' Steel I-beam to carry a load. That's right only 12'. You probaly need a Steel I- beam for 23' but maybe not, I've used wood for 23' in alot of houses that I've framed but it's all done by an Architect or Engineer and it's all on the plans which I assume you don't have and this will not be inspected.

   At the ends of the I-beam are columns that have a plate welded to  the top and bottom of the column and then bolted into the bottom of the I-beam and then bolted into the concrete floor that has footings under it. That's not for me to say or anyone else but an Architect and an Engineer and if anyone does tell you that's not one would you feel comfortable with a 23" opening in your house? 

   Joe Carola

   
   

   ---

   Edited 11/14/2003 7:45:38 AM ET by Framer

1. 
   JoeyB | Nov 14, 2003 05:34pm | #13

   Thanks for all the replies. I can now foward this info to my friend who is interested in doing this to his house. I have a sneaky feeling he is going to change his mind!

1. 
   fdampier5 | Nov 14, 2003 09:09pm | #14

   steel is gonna carry the most weight with the least cost but there are other ways to span that.  a glue lam or evan a solid beam if it's the right kind..    the size might shock you.. to carry my house over a 20 foot span I needed two 12x12's  side by side (didn't have room to go taller) 

          since my house is a timber frame I just couldn't bring myself to use steel..

2. 
   BillHartmann | Nov 14, 2003 10:24pm | #15

   Not having any idea of what he wants to do with that much clear span, but try thinking outside the box (but inside the house) <G>.

   For example if that is going to be an open kitchen then in the middle of that span put an counter top and a couple of post to support the beam.

   Or a building in bookcase with the post hidden in it.

   With a little creativeness he can still have a "largely" open span with with some mid span support that no one would suspect.

   And that would greatly reduce the size of the beam.