Putting in a big beam for my barn build. it'll hold up the upstairs and and over hanging balcony that has 4' of it unsupported. Least wise that's what I am wanting. The area that this covers is 20 deep x 32 wide. The balcony is 4 additional depth and still 32' wide. A SYP beam that has one support at the 19' mark only needs to be a 10x14, yet to over hang it 4' unsupported if my cypherin is correct needs to be a 12x18. Is my cypherin wrong?
Thanks
I'm trying to get by using one post. If I need to go to 2, then i'll not overhang. Thus the fuss.
Im not exactly picturing it. But can you brace the overhang back into the post that the beam is on?
Ditto, full drawings needed. People tend to forget, a brace puts a side buckling load on an already end loaded post. Push down on a yardstick from the end. Now while doing that also push on it from the side. That complex combined interaction equation is a whole other level of fun and depending on the slenderness ratio of the post often results in "don't do it".
Double the post. Truss the post. Add another member in a Г + / configuration all the way to the ground with plywood sides to form a monocoque structure. Or make it a steel beam.
A poor guy woulda had this built from pallet wood already cmawn. ;D
This is all exposed. Post be a 12x12 or a matching post to beam.
I'll try and do some drawings, but they'll prolly be later after ballgames. I'll try and splain it betters now
Total length on beam is 24'6". The 6" is buried in north wall. Beam runs south 24'. Post is at the 19' mark. This beam is in the middle of a 20' deep (north/south) X 32' wide (east/west) kitchen and dining room. Above this beam is the 3x12x16'6" floor joists 2" OC that are under the 2 upstairs bedrooms. The 4' over hanging balcony is south side of the bedrooms.
Pictorial of the drawing
(https://forestryforum.com/gallery/albums/userpics/53840/20210501_063942.jpg?easyrotate_cache=1619869186)
I have almost always used a steel flitch plate for cantilevers. One can be hidden inside two beams.
Yeah, i used that on my old farm house remodel years ago. needed the ceiling height, so used i think 5, 2x8 and put a thin plate betwix them all. worked great.
I could use 2 beams, but prefer one. The 10" x 14" SYP beam i can order is about $1,250 dried. I can get a green one much cheaper, but prefer not the hassle of the green build. I can also make the SYP beam bigger. I can also buy some reclaimed, but they are darn expensive. around $2,700 for a 12" x 15"
For wide span doorways my dad would sister a pair a 2x lumber with a steel flat plate bolted in tbe center rather than plywood to shim for thickness. No sag or sheetrock cracks 20yrs later.
Quote from: Don P on April 30, 2021, 11:45:46 AM
Ditto, full drawings needed. People tend to forget, a brace puts a side buckling load on an already end loaded post. Push down on a yardstick from the end. Now while doing that also push on it from the side. That complex combined interaction equation is a whole other level of fun and depending on the slenderness ratio of the post often results in "don't do it".
knock, knock if ya ain't too busy
I was politely thinking, "that bunch of chicken scratches ain't goin on the fridge". I can't make heads or tails of it. Back out and draw more of the footprint, surrounding walls, you've lost me.
Quote from: Don P on May 02, 2021, 12:30:36 PM
I was politely thinking, "that bunch of chicken scratches ain't goin on the fridge". I can't make heads or tails of it. Back out and draw more of the footprint, surrounding walls, you've lost me.
Alrighty
Oh you're fine. Frankness is best although I don't know frank......
Be later, at ball games
I cant tell if its a ground view or a birdseye view.
Quote from: Don P on May 02, 2021, 12:30:36 PM
I was politely thinking, "that bunch of chicken scratches ain't goin on the fridge". I can't make heads or tails of it. Back out and draw more of the footprint, surrounding walls, you've lost me.
Heres ya goes. Was able to get this done
They won again, so one more game at 4
Anyways, the yellow is what will be up upstairs. Orange is the beam
Floor joists are 3x12 2' OC
Proposed beam is 10x14x24 SYP
(https://forestryforum.com/gallery/albums/userpics/53840/20210502_151410.jpg?easyrotate_cache=1619986477)
Quote from: mike_belben on May 02, 2021, 04:10:44 PM
I cant tell if its a ground view or a birdseye view.
birdy
"Plan view"
And that is why we use drawings, that is nothing like what the word pictures had conjured up in my head. Don't try to describe stuff, draw it and draw it well.
Tributary area supported by the beam is highlighted within the red box;
(https://forestryforum.com/gallery/albums/userpics/10017/20210502_151410t.jpg?easyrotate_cache=1620010248)
Trib width would be 16' x 50psf (40LL+10DL) = 800 lbs per lineal foot load on the beam.
This calc;
https://forestryforum.com/members/donp/oerhangbm.htm
You're cutting it mighty fine in #1SYP
Quote from: Don P on May 02, 2021, 11:08:40 PM
"Plan view"
And that is why we use drawings, that is nothing like what the word pictures had conjured up in my head. Don't try to describe stuff, draw it and draw it well.
Tributary area supported by the beam is highlighted within the red box;
(https://forestryforum.com/gallery/albums/userpics/10017/20210502_151410t.jpg?easyrotate_cache=1620010248)
Trib width would be 16' x 50psf (40LL+10DL) = 800 lbs per lineal foot load on the beam.
This calc;
https://forestryforum.com/members/donp/oerhangbm.htm
You're cutting it mighty fine in #1SYP
Yup, that all be correct
Makes it all like easy. No confusing what someone thinks they spellin and what someone thinks they readin.......
passes by 5% if I include the post area span of 234"
passes by 20% if i don't include post area span of 12", since that area isn't spanned
seems since you mentioned skinny (well ok, you didn't say that directly, but you're not talking beauty ;D), that the post area should be included.......?
what % over do you consider is 'healthy'
Thanks
A pass is good, just watch the material quality. For kicks try an LVL... Fb 2800, E 2.0, Fv 280. Each ply of an LVL is 1-3/4" thick, 11.875 tall or 14" tall
I got an overhung beam [shed type roof] sitting on 2 posts, reaching way out to hold up this roof, no post. I was afraid if snow stayed up there it could tip and fail so I hung a barrel of concrete on the back. The beam is steel tube.
For this it isn't a tipping, see-saw, problem. The "control" is bending failure in the main 20' span rather than in the 4' overhang. I would not use tile in the bathroom on that kind of beam span or joist span and spacing. Experiment with making the overhang longer and watch what it does to the main span bending moment and point of max moment, the see-saw is on that end.
Quote from: Don P on May 03, 2021, 08:58:44 AM
For this it isn't a tipping, see-saw, problem. The "control" is bending failure in the main 20' span rather than in the 4' overhang. I would not use tile in the bathroom on that kind of beam span or joist span and spacing. Experiment with making the overhang longer and watch what it does to the main span bending moment and point of max moment, the see-saw is on that end.
shucks. Thought that'd be alright on the span. 3 questions if I may.
1. what size beam wood you be comfy with if one wanted tile
2. and if not tile, but just what you'd put
3. how far could you move the post back if any and if any, wood that solve the above question? Reason I had post there was the wall upstairs being directly above
thanks
With a 20' beam span and wide centers on joists I doubt tile would hold up, I'd use sheet vinyl or a laminate. Don't move the post back if there is a wall above, adding another post would help but the joists are long span and widely spaced so bag the tile. Basically get all deflections, beam, joist, floor sheathing to L/480 or stiffer and it has a chance, but it probably still will crack.
Having an issue with getting that SYP beam i was suppose to be getting...... I can go reclaimed, but that's over 4k. Nope. Thinking about metal. Prefer rec tubing. I'm coming up with a 12x16x.5 has .314 deflection vs .220 for the wood beam. That can't be right, can it? I'm using 16,440 lbs for the force.
Here's the link Rec tubing calculator (https://www.easycalculation.com/engineering/mechanical/deflection-hollow-rectangular-beams.php)
Quote
"Plan view"
And that is why we use drawings, that is nothing like what the word pictures had conjured up in my head. Don't try to describe stuff, draw it and draw it well.
Tributary area supported by the beam is highlighted within the red box;
(https://forestryforum.com/gallery/albums/userpics/10017/20210502_151410t.jpg?easyrotate_cache=1620010248)
Trib width would be 16' x 50psf (40LL+10DL) = 800 lbs per lineal foot load on the beam.
This calc;
https://forestryforum.com/members/donp/oerhangbm.htm
You're cutting it mighty fine in #1SYP
That is a simple beam calc, a beam between 2 supports. What we've been talking about is a beam with an overhang. That is a different set of equations, the load on the overhang is reducing the deflection. I also do not recognize the equation he is using, not saying I've run it against the standard equation to see if he is getting the same result by another path but based on the spelling and notational peculiarities I'm a little leery. Might try engineers edge for a calc.
It would take more rewriting than I have time to modify the wood calc for this. This is the equations you need, it comes from the AISC steel construction manual. The bottom 2 equations are deflection;
(https://forestryforum.com/members/donp/unover1post.jpg)
For I his equation is correct;
QuoteMI for hollow rectangle beams = ((Width * Height3) - (Inside_width * Inside_height3)) / 12
E is 29,000,000
For x use the equation locating the point of zero shear in the middle graphic. for x
1 use a.
Quote from: Don P on May 28, 2021, 09:11:32 PM
That is a simple beam calc, a beam between 2 supports. What we've been talking about is a beam with an overhang. That is a different set of equations, the load on the overhang is reducing the deflection. I also do not recognize the equation he is using, not saying I've run it against the standard equation to see if he is getting the same result by another path but based on the spelling and notational peculiarities I'm a little leery. Might try engineers edge for a calc.
It would take more rewriting than I have time to modify the wood calc for this. This is the equations you need, it comes from the AISC steel construction manual. The bottom 2 equations are deflection;
(https://forestryforum.com/members/donp/unover1post.jpg)
For I his equation is correct;
QuoteMI for hollow rectangle beams = ((Width * Height3) - (Inside_width * Inside_height3)) / 12
E is 29,000,000
For x use the equation locating the point of zero shear in the middle graphic. for x1 use a.
yes, that's a simple beam, but as you said, if with an overhang it acts as a deflection in the main support area. If beam passes simple beam, it passes the one with the small overhang
That's more math then I trust myself to do, to just get an idea what might work, to see if cost effective. simple math i'm better then most, but that wood take me to area's of my mind that haven't been explored in many years....... :laugh:
I'll also try and run it by my engineer, but he's not always conducive to answering things just to get an idea if
scratch all that. Just will use an H beam like your calcs allow, but heavier then needed. maybe a 14x43. Not that it is needed. just looks better i think. I can inlay the web w/ wood. Maybe drill 1" holes every 2' and use sq headed bolts and nuts to bolt it
Now what post does one use......
Quote from: Sedgehammer on May 29, 2021, 10:20:32 AM
Now what post does one use......
A mighty big and well protected one because your life and entire structure may well depend on that single post. Better think about footing required too. ::)
@Gary_C (https://forestryforum.com/board/index.php?action=profile;u=1467) yup. agreed
@Don P (https://forestryforum.com/board/index.php?action=profile;u=17) if you wood chime in on this please sir
according to this column toolbox (http://www.timbertoolbox.com/Calcs/columncalc.htm) and the numbers used, a SYP #1, 10x10 passes easily. But maybe my inputs are off, as it looks like a 2x2 wood pass, so somethings wrong i figure
I used the following inputs;
unbraced length = 106" ceiling is 10' - a 14' H beam = 106"
depth = 10"
width = 10"
compression = 7,130
elasticity = 1.79
load = 16,044
and what sized footing wood be recommended
Murphy's Law should be be telling you to look for another alternative. Putting all your eggs in one basket is risky.
Eggs are for digin1 ....... ;D
Looking at all options at this point, but I think a 10"x will suffice, but I'll see if Don or someone else can make tails or heads off my inputs were correct
I think a 3' sq x 1' deep footing will be more then adequate from what I have read
I could look at the calc but with those dimensions there's another way to look at it. If the post is 1" thick in least dimension for each foot of height... that is if the post is a 10x10 and is 10' tall, it isn't going to fail by buckling. Old engineers called that ratio a short column. The only check you need to do is compression, it will fail by crushing. Take the 100 square inch post top and multiply it by the allowable Fc parallel to grain, shoot low, use 525 psi (there's your error above) =52,500 lbs allowable load. It is a pretty stout basket.
Footing, the distance from edge of post horizontally to edge of footing is also how thick it should be. Close enough there. At least a # grid of rebar in the lower third, no steel closer than 3" to soil anywhere.
Footing size = load/allowable soil bearing capacity. Assuming 2,000psf allowable soil capacity x 9 sf of footing = 18,000 lbs allowable, plastic clays can be down around 1500 and muck can be worthless. Think about your wheel loads and whether you stick trucks. Too small is no bargain if its soft.
Thanks!
Stout indeed! Me bride wants to use one of our largest ERC logs that we cut down this spring. I see it's even stouter in that regard. I'm just having a hard time with right angled interior wood/metal w/ a round post...... does not compute, does not compute..... :o
It does not have to compute, just accept it . You know she right.😁
Quote from: trimguy on May 31, 2021, 06:49:48 PM
It does not have to compute, just accept it . You know she right.😁
i've never seen a woman be so right about so many things and she's not arrogant about it. she's just smart. with that said, she's not always right......... smiley_crying
Quote from: Don P on May 30, 2021, 08:41:55 PM
I could look at the calc but with those dimensions there's another way to look at it. If the post is 1" thick in least dimension for each foot of height... that is if the post is a 10x10 and is 10' tall, it isn't going to fail by buckling. Old engineers called that ratio a short column. The only check you need to do is compression, it will fail by crushing. Take the 100 square inch post top and multiply it by the allowable Fc parallel to grain, shoot low, use 525 psi (there's your error above) =52,500 lbs allowable load. It is a pretty stout basket.
If i twas to use a green syp post. say a 12x12 or even larger, what amount of end shrinkage wood I have? i know it wood take several years for it to completely dry, but is it an amount that wood have sheetrock not happy?
Very little shrinkage in length unless it is full of juvenile wood or twisted grain.