Replace wood with steel
Replace wood with steel
(OP)
A friend of mine is trying to replace a support column and wood beam in his garage, which is under half of his house. He asked me, a structural engineering student, to suggest a steel beam that could replace the combined supports. The available space for the replacement is equal to the existing occupied space.
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9.5”
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-----------------------------11’--------------------I-----------------------------11’------------------------------
I
I
I 6.5’
I
I
I
Basically, what I tried to illustrate above, there are 3 2x10s together forming a 4.5” x 9.5” cross section that spans 22’ with a 6.5’ steel column supporting the middle. The column is a 2.5” diameter, 1/8” thick steel tube. There is no way to find the actual load that this assembly holds, but I want to find something that is reasonably effective and safe. My suggestion is 2 C7x14.5 beams, back to back of course. Can I get any recommendations from actual professionals?
___________________________________________________________________________________________________________________
9.5”
___________________________________________________________________________________________________________________
-----------------------------11’--------------------I-----------------------------11’------------------------------
I
I 6.5’
I
I
I
Basically, what I tried to illustrate above, there are 3 2x10s together forming a 4.5” x 9.5” cross section that spans 22’ with a 6.5’ steel column supporting the middle. The column is a 2.5” diameter, 1/8” thick steel tube. There is no way to find the actual load that this assembly holds, but I want to find something that is reasonably effective and safe. My suggestion is 2 C7x14.5 beams, back to back of course. Can I get any recommendations from actual professionals?






RE: Replace wood with steel
Mike McCann, PE, SE (WA)
RE: Replace wood with steel
RE: Replace wood with steel
Now don't take this the wrong way, BUT, if you're going to be a structural engineer how can you say "There is no way to find the actual load that this assembly holds"? As an exercise, there are two ways to do it: draw up the framing and calculate the loads or using the section properties of the members work backwards to determine their capacity. Use conservative values for shear and bending.
Why not use a wide flange? The channels need to be bolted together.
RE: Replace wood with steel
The greatest trick that bond stress ever pulled was convincing the world it didn't exist.
RE: Replace wood with steel
TTFN

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Of course I can. I can do anything. I can do absolutely anything. I'm an expert!
RE: Replace wood with steel
RE: Replace wood with steel
Sorry but you really are out of your depth. You need to tell your "friend" to contact a real Structural Engineer in your area who is qualified to undertake this engagement.
RE: Replace wood with steel
RE: Replace wood with steel
The OP's problem may appear to be a "simple" one, but, the OP will learn that almost NOTHING is ever "simple." People LIE, drawings LIE, and construction LIES. Unless the OP is experienced enough to recognize where someone lied or omitted about what was done, the OP is potentially on the hook for unintentional deaths or injuries. Given that it's unlikely that the OP has the requisite professional liability insurance, their future in structural engineering could be very short indeed.
TTFN

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Need help writing a question or understanding a reply? forum1529: Translation Assistance for Engineers
Of course I can. I can do anything. I can do absolutely anything. I'm an expert!
RE: Replace wood with steel
RE: Replace wood with steel
RE: Replace wood with steel
Where are you studying? Just curious as I have found young Canadian graduates are shown so many disasters and collapses in their undergraduate degrees that many of them are frightened of their own shadows, needing hand holding for years in some cases. The New Zealand graduates are far less fearful, but know enough to know what they don't know, and to refuse work outside of their depth. You seem rather confident to continue guessing, to the detriment of your future career.
Man (or woman) up and tell your friend to go hire someone local. Worst case you're going to get yourself or someone else HURT; best case is significant economic loss or collapse of this structure.
RE: Replace wood with steel