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Gentlemen:
I am quoting a project where I will be building a two story addition on the back of a two story colonial. I will be opening up the back of the house such that the existing rooms on both floors will extend into the addition. The beams that will replace the bearing walls will be buried in the floor framing with the existing and new joists hung from either side.
The plan currently calls for steel I beams to support these loads the largest of which is 10×39 for a 20 foot span (e. 800 lbs.) at the juncture between the first and second floor. The use of a big piece of steel creates a lot of problems on a remodel job with lousy access (as bad as it gets!) I therefore am interested in a built up beam that would do the job. Are there any tables comparing steel to flitch type beams? In any ones experience can a flitch beam replace this piece of steel?
I did an addition several years ago that was quite similar with much smaller spans. We used built up lams and it was gravy.
Thanks in advance for your thoughts on this.
Tom
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Not quite what you are asking for, but take a glance at:
http://www.timber.org.uk/beamup.html
they claim that by using rebar and epoxy in a channel cut in a wooden beam, they can double the strength of the wooden beam. Looks like an interesting solution where you want an exposed beam to appear as a solid beam, but I assume you could do the same thing by filling a boxed beam so you wouldn't have to cut the channel.
*Bridge timbers once spaned this distance and they carried trains. Why not check with the industry associations and also the Timber Framers Guild of North America. Manufactured gluelams and site built glue/nailed and various types of box beam are suprisingly strong.
*There was an article in FH some years back which had an example table showing the relative strengths of flitch beams, glulams, steel, etc. If you look back in some old issue indexes, you should be able to find it. My recollection is that a flitch beam is not efficient in terms of weight or depth required to carry a given load, but was inexpensive and easy to put up. The article probably gives the reference used for strength comparisons. I would probably check Architectural Graphic Standards first if I were looking for this info. Good luck. Rich.
*tommy boy... check the archives.. this subject was discussed at length about december or january/ february..some real good info was passed....mike
*Thanks guys, I had checked the archives and got quite a few hits but didn't find what I wanted. Mike if you recall the exact discussion, maybe you could direct me to it. I read the board pretty thoroughly and don't recall any comparisons such as I mentioned.FYI, I have that JLC article and it was helpful, its in Sept. 99. Also on the JLC cdrom I found an article in the Sept. 92 issue that has a table "Equivalent Strengths: Flitch Beams vs. Built-up Wood Beams And Steel I Beams", exactly what I was looking for. Proble is it only goes up to 10x22, and that calls for 2 11x1/2 steel plates with 3 12x members. I'm probably looking at 3 3/4" pieces of steel at probably 500 lbs. per piece which would effectively double the price. Thanks for the input. Anyone else have any thoughts on this. I seems to me that it would be alot harder to handle the heavier steel and connect it to the wood in tight quarters.Tom
*Tom - wouldn't you need a stamped design from an architect or engineer to make a change like that anyway? I'm gettin' gunshy of makin' serious deviations from aproved structural members. The opportunity for liability problems far exceeds the gratification of coming up with something on my own...maybe I'm just losin' my nerve.
*Jim,Affirmative on the stamp. I'm going to bid it with the steel, I just think I can make the job easier, if I can do it in pieces. Do you have any ideas for maneuvering a piece of steel like this into place without machines? It's gonna take eight guys to safely get it on the deck so I can jack it into place. Alot of times I'll roll them on pieces of schedule 40 but I gotta go up steps through gardens, etc. And that's just the first floor beams. I guess I hate doing jobs like this that I would design around if it was for myself. Tom
*tom...i just spent a half hour searching under ((beams ))) and couldn't find the flitch beam discussion... sorry
*Mike,Thanks for trying, that's about the same luck I had.Tom
*Do you have "Labor Ready" nearby? They are a temporary workforce around here. I've never tried them, but maybe you could hire 10 guys for 2 hours or something. How about those tongs that they use to move railroad rails? They might be rentable. Sounds like a good challenge, for sure.Another thing, I just reread your original post. Is that "10x39" I beam 10" wide by 39" tall? That's a hell of a beam there bro. What about building a box beam in place? Or maybe a series of girder trusses? Probably stuff other folks have mentioned, but it's morning, and my mind is connecting the dots so I'll spill them out...
*Tommy,I assume your 10X39 is a 'W'. The heaviest 10" beam I found on the one list I looked at was a 10X26. You only have 10" of depth to play with and a 20' span. If the plans call for a 10X39 you won't find anything to replace it unless you increase the depth well beyond 10". Looks like you'll need a few strong backs.Disclaimer: Not an engineer; don't know all the details.Good Luck,Jerry