The house is 20 feet wide and the beam is not exactly in the middle.
I'm not at home currently, so I can only estimate that it's 8 feet
from one wall and 12 from the other.
You're suggesting that the column at 4 feet could be replaced by a 20
feet long steel beam?
[Also, from previous posts, there is a column coming down at x = 4
feet carrying half the load from a 16 foot span of floor joists for
the second story.]
The only difference between these two plans is the column carrying
the second story floor joists. The load from the first story floor
joists is the same in both case, 16 feet of span. But in Plan 1, the
ground floor column is above your basement column, while in Plan 2,
the ground floor column hits the basement girder 4' from the basement
column, imposing extra bending moment on the girder.
By my calculations, which I am not qualified to do, that extra point
load increases the maximum moment in the basement girder by a factor
of 25/16, or plus 56%. [Assuming the floor joist loads for the first
and second story are the same.] So unless your steel flitch plate
solution for Plan 1 is at the edge of what is feasible, I would expect
it to be possible to do Plan 2 the same way using more or thicker
Of course, there may be other irregularities not presented, or there
may be a difficulty in making the connections properly in Plan 2.
Your structural engineer should be able to tell you.
Sounds about right. My thinking, (again, w/o _any_ calculations :) )
while a little more installation effort, was to extend the side plate
the full or nearly the full distance and beef it up to 3/8" or even
1/2". I'm pretty confident that would handle the deflection pretty
easily if the vertical loads are on the columns, wherever he chooses to
end up putting them.
But, he's got an enganier who's gettin' the big bucks and my
registration ain't no good anywhere but TN and here and I'm not working
anyway (other than farming again, that is)... :)
Great minds think alike........... flitch plates with a piece of
angle iron or channel welded on to serve as a joist seat.
I would suggest using plates both on both sides (symmetry & all).
Rather than bolting through I would recommend to your engineer that
plates have offset hole patterns & use Simpson SDS 2 inch "lags".
They usually can be installed without pre-drilling unless the timber
is very hard / dry.
Make sure hole pattern considers joist locations.
You didn't give the exact dims of the 3x12's (true 12" or 11.25"?) or
the depth of the joists (2x8's?)
but my rough calc says that plates (1/2" x 12") both sides should
just about do the trick.
Tell your engineer that "through bolting sucks", results in a very
sloppy fit up
and removes too much material from the original member
The Simpson SDS are the way to go.
How about some photos?
The 3x12 are probably true 12 feet, but it's hard to know for sure due
to the fact that they're not completely visible (haven't torn down
I did measure the joists, but can't remember off the top of my head. I
think they're 2x12.
You're saying that with a single column @ 16 feet and 2 1/2" plates
of 12 feet along the beam should hold up? There's a split @ 12 feet in
the beam, so would these new plates span 6 feet on both sides of the
Is this achieved by the use of the SDS instead of bolting through, or
is that a separate concern?
The engineer's current solution is 1/4 inch U spanning 20 inches on
both sides of the split, but requires 2 columns: @ 4.5 and 20 feet.
The U would be bolted through the member with 9 1" bolts on either
Interesting, I'll see what he has to say about this.
Either trust your engineer, or hire a second one as a double check.
Do you not intend to get a permit and a municipal inspection for this
My city would require an engineer's drawing and an engineering sign
off on the correctness of the work carried out for the type of
structural alteratrion you contemplate.
Incidentally, the job you outline is neither unusual nor complicated.
Pay an engineer!!!
Ken in calgary.
On Jun 23, 2:07 am, firstname.lastname@example.org wrote:
I was referring to the contractor, not the engineer.
Same here. But the engineer's plan will layout the result of the work,
not exactly how the work should be carried out. For example, it says
that proper support must be put in place during the work. It doesn't
say how to put that proper support in place.
By posting here, I was hoping to get an insight on how to properly
execute the plan. I want to be able to verify that the contractor's
solution is sensible.
I have a similar set up with beam and joists, I just added supports
and thick plate steel under the beam the leveled it slowly. Why do you
need a new beam, why cant you just add supports to what you have. When
you start jacking to make it level things may break, I had a few
joists I had to sister on new joists but your idea of removing what is
there is full of risks you cant imagine, like everything failing
completely, the money and time you will waste in proper jacks to
support everything while removing the old beam is taking a little job
and making it major.
Yeah, that's what I started to realize. I figured it would be simple
to replace the existing beam, but I think now that this is full of
traps and a much bigger job than I expected.
I don't need to replace anything, I'm trying to get rid of a column in
the basement. If it's too complex/expensive, I can live with the
column there. Currently, I'm still looking at the different
possibilities to assess their complexity and cost. I'll take a
decision once I have all the info I think I need.
Getting some external insight is very helpful for taking this
Thanks for your comment.
If you intend to remove the existing wood beam, you will need to
build a temporary wall on each side of the beam that will carry
the load while you remove and replace. Getting a beam of size
into location and situated where it can be lifted into position
are usually the hard part. There was a similar project taken on
this past year in JLC.
This one is your project exactly:
Here is one other approach:
Here is another, though you may have to pay to access the archive
Keep the whole world singing . . .
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