Hi everyone,

I'm interested in knowing how one would go about replacing part of the
main beam (basement) of a 1926 house.

I've consulted a structural engineer to figure out the required size/
strength of the new beam (probably steel). He will also be specifying
the size of the required column and its footing. I'm currently trying
to figure out how the work can be accomplished and would appreciate
some input.

The beam to be replaced is made of 3 wooden 3x12. My issue is with the
fact that the floor joists are hanging from that beam (as opposed to
being supported by it). Sitting on this beam is also a 4-feet section
of a load-bearing wall.

I figured that I could support the floor joists with jack posts or
some temporary load-bearing wall on both sides of the existing beam,
but how can I support the 4-feet section of wall without being in the
way of the new beam to put in place?

Whatever I put in place there must be removed in order to put in the
new beam, but I can't put in the new beam without supporting that
wall... What kind of approach would you suggest to take here?

Phil wrote:
Hi everyone,

I'm interested in knowing how one would go about replacing part of the
main beam (basement) of a 1926 house.

I've consulted a structural engineer to figure out the required size/
strength of the new beam (probably steel). He will also be specifying
the size of the required column and its footing. I'm currently trying
to figure out how the work can be accomplished and would appreciate
some input.

The beam to be replaced is made of 3 wooden 3x12. My issue is with the
fact that the floor joists are hanging from that beam (as opposed to
being supported by it). Sitting on this beam is also a 4-feet section
of a load-bearing wall.

I figured that I could support the floor joists with jack posts or
some temporary load-bearing wall on both sides of the existing beam,
but how can I support the 4-feet section of wall without being in the
way of the new beam to put in place?

Whatever I put in place there must be removed in order to put in the
new beam, but I can't put in the new beam without supporting that
wall... What kind of approach would you suggest to take here?

What's the engineer say since he has access to all the particulars?

I'm curious about why this is needed now in an 80+ yr dwelling. Unless
there's a definite need for replacement, I'd be more for simply adding
adequate hangers and _perhaps_ some additional support if it does have
some deflection issues in the beam itself.

As per usual, too little info from afar, particularly for structural
questions...

--

On 2010-06-21, Phil wrote:

I figured that I could support the floor joists with jack posts or
some temporary load-bearing wall on both sides of the existing beam,
but how can I support the 4-feet section of wall without being in the
way of the new beam to put in place?

What is the 4 foot section of wall supporting, and can you unload that
section of wall? For example, if it is carrying ceiling joists, you
could build temporary walls directly above the temporary walls
carrying the floor joists.

Cheers, Wayne

On Jun 21, 3:19*pm, Phil wrote:
Hi everyone,

I'm interested in knowing how one would go about replacing part of the
main beam (basement) of a 1926 house.

I've consulted a structural engineer to figure out the required size/
strength of the new beam (probably steel). He will also be specifying
the size of the required column and its footing. I'm currently trying
to figure out how the work can be accomplished and would appreciate
some input.

The beam to be replaced is made of 3 wooden 3x12. My issue is with the
fact that the floor joists are hanging from that beam (as opposed to
being supported by it). Sitting on this beam is also a 4-feet section
of a load-bearing wall.

I figured that I could support the floor joists with jack posts or
some temporary load-bearing wall on both sides of the existing beam,
but how can I support the 4-feet section of wall without being in the
way of the new beam to put in place?

Whatever I put in place there must be removed in order to put in the
new beam, but I can't put in the new beam without supporting that
wall... What kind of approach would you suggest to take here?

Why cant you leave in the old and add support, if you have to ask here
without even providing and real info I think you are in for trouble.

On Jun 21, 1:19*pm, Phil wrote:
Hi everyone,

I'm interested in knowing how one would go about replacing part of the
main beam (basement) of a 1926 house.

I've consulted a structural engineer to figure out the required size/
strength of the new beam (probably steel). He will also be specifying
the size of the required column and its footing. I'm currently trying
to figure out how the work can be accomplished and would appreciate
some input.

The beam to be replaced is made of 3 wooden 3x12. My issue is with the
fact that the floor joists are hanging from that beam (as opposed to
being supported by it). Sitting on this beam is also a 4-feet section
of a load-bearing wall.

I figured that I could support the floor joists with jack posts or
some temporary load-bearing wall on both sides of the existing beam,
but how can I support the 4-feet section of wall without being in the
way of the new beam to put in place?

Whatever I put in place there must be removed in order to put in the
new beam, but I can't put in the new beam without supporting that
wall... What kind of approach would you suggest to take here?

If it aint broke, dont fix it.
What is the current configuation not doing that it should be doing?
Are floor joists doing their job?

Where is the house located? High winds? seismic?

My house was built in 1930 (SoCal) I have not had to mess with any of
the original work unless I was changing load paths, fixing dry rot or
1930's plumber damage.

Photos would help a lot; overall shots & closeups.

cheers
Bob

"Phil" wrote

I've consulted a structural engineer to figure out the required size/
strength of the new beam (probably steel). He will also be specifying
the size of the required column and its footing. I'm currently trying
to figure out how the work can be accomplished and would appreciate
some input.

Why not ask the engineer? He can see it, we cannot. I'm not even going to
try to tell you because no matter how I read your post and no matter how
well you read my reply, there is a potential for serious error. I'd want to
see it in front of me. Ask the engineer or a good contractor.

On Jun 21, 4:19*pm, Phil wrote:
Hi everyone,

I'm interested in knowing how one would go about replacing part of the
main beam (basement) of a 1926 house.

I've consulted a structural engineer to figure out the required size/
strength of the new beam (probably steel). He will also be specifying
the size of the required column and its footing. I'm currently trying
to figure out how the work can be accomplished and would appreciate
some input.

The beam to be replaced is made of 3 wooden 3x12. My issue is with the
fact that the floor joists are hanging from that beam (as opposed to
being supported by it). Sitting on this beam is also a 4-feet section
of a load-bearing wall.

I figured that I could support the floor joists with jack posts or
some temporary load-bearing wall on both sides of the existing beam,
but how can I support the 4-feet section of wall without being in the
way of the new beam to put in place?

Whatever I put in place there must be removed in order to put in the
new beam, but I can't put in the new beam without supporting that
wall... What kind of approach would you suggest to take here?

I think some pictures or drawing are needed to get any useful advice
ouf of the newsgroup. Typically you build temporary walls or use jack
posts to take the load off. In the case of the wall you would need to
build one or two temporary walls along it. You may also need to nail
some cross pieces at the ends to keep it from falling thorugh when you
remove the 3x12 under it.

I do agree with some of the other posters, is it not possiel to repair
what you have? Or are you trying to get an uninterrupted span where
I'm guessing there must be some posts holding up these 3x12s?

On Jun 22, 8:05*am, jamesgangnc wrote:
On Jun 21, 4:19*pm, Phil wrote:



Hi everyone,

I'm interested in knowing how one would go about replacing part of the
main beam (basement) of a 1926 house.

I've consulted a structural engineer to figure out the required size/
strength of the new beam (probably steel). He will also be specifying
the size of the required column and its footing. I'm currently trying
to figure out how the work can be accomplished and would appreciate
some input.

The beam to be replaced is made of 3 wooden 3x12. My issue is with the
fact that the floor joists are hanging from that beam (as opposed to
being supported by it). Sitting on this beam is also a 4-feet section
of a load-bearing wall.

I figured that I could support the floor joists with jack posts or
some temporary load-bearing wall on both sides of the existing beam,
but how can I support the 4-feet section of wall without being in the
way of the new beam to put in place?

Whatever I put in place there must be removed in order to put in the
new beam, but I can't put in the new beam without supporting that
wall... What kind of approach would you suggest to take here?

I think some pictures or drawing are needed to get any useful advice
ouf of the newsgroup. *Typically you build temporary walls or use jack
posts to take the load off. *In the case of the wall you would need to
build one or two temporary walls along it. *You may also need to nail
some cross pieces at the ends to keep it from falling thorugh when you
remove the 3x12 under it.

I do agree with some of the other posters, is it not possiel to repair
what you have? *Or are you trying to get an uninterrupted span where
I'm guessing there must be some posts holding up these 3x12s?

Thanks for all the replies. I didn't provide enough information, so
I'll to give some more here. Please let me know if were still missing
important bits!

The goal is not to repair, but to remove a column in the basement. I'd
like to have an uninterrupted span of 16 feet in the basement to use
as a family room.

The current situation is as follows: the beam is in 3 sections of 12
feet. It's currently supported by 3 columns: one at 8 feet, 16 feet
and 24 feet from the front wall. On the ground floor, the previous
owners made some modifications and removed part of the original load-
bearing wall. From the front wall: there is now a 4-feet section of
remaining wall, a 16 feet opening and 6.5 feet of wall. That opening
is supported by a steel beam with columns on either ends (approx 4
feet and 20 feet from the front wall).

Here's some amazing ASCII art that depicts the current situation. If
you look at this with a mono-spaced font (such as courier) it should
come out ok:

U ||||||||||||||||||||||||||
------------------
G ||||| |||||
===================----------------------
B || | | | ||


- Legend -
U : Upper floor (roof left out)
G : Ground floor
B : Basement
- : existing beam
| : existing column
||: existing wall (load-bearing or foundation wall)
= : existing section of beam to be replaced

By replacing that section of beam, I can remove that first column and
only have a single one at 16 feet which is ok in regards to what's
around it.

I did look into another solution: move the 2 columns in the basement
directly under the columns on the ground floor: 4 feet and 20 feet.
Then place a re-enforcing steel plate to hold up the two sections of
wood beam. The engineer made those plans and made the specs of the
columns, footings and steel plate. The downside of this plan is that I
have to take down additional walls in the basement, the footings are
quite large (4x4x1) and I end up having 2 columns in the basement. So
I asked the engineer to look into a single-column solution to see if
this alternative plan is feasible and what are its downsides. I'll be
getting these plans in the next few days.

Obviously, I'll also be asking the engineer about how to support this
wall section and the floor joist. But I thought I could get some
insight here also.

The goal is to know how one goes about doing this before I call
contractors. I like being informed independently from the people that
will be doing the job, otherwise they could be doing some nasty stuff
and I wouldn't the wiser... I'm trying to stay out of trouble, not get
into it!

Some additional info:
House is located in very safe, non-seismic place of the world (lived
here 30 years, we've had 2 below 5)
No hurricanes or tornadoes have ever gone by
Ground is very dense
Neighbours are attached on both sides

Thanks for all the replies!
Phil

On Jun 22, 10:29*am, Phil wrote:
On Jun 22, 8:05*am, jamesgangnc wrote:





On Jun 21, 4:19*pm, Phil wrote:

Hi everyone,

I'm interested in knowing how one would go about replacing part of the
main beam (basement) of a 1926 house.

I've consulted a structural engineer to figure out the required size/
strength of the new beam (probably steel). He will also be specifying
the size of the required column and its footing. I'm currently trying
to figure out how the work can be accomplished and would appreciate
some input.

The beam to be replaced is made of 3 wooden 3x12. My issue is with the
fact that the floor joists are hanging from that beam (as opposed to
being supported by it). Sitting on this beam is also a 4-feet section
of a load-bearing wall.

I figured that I could support the floor joists with jack posts or
some temporary load-bearing wall on both sides of the existing beam,
but how can I support the 4-feet section of wall without being in the
way of the new beam to put in place?

Whatever I put in place there must be removed in order to put in the
new beam, but I can't put in the new beam without supporting that
wall... What kind of approach would you suggest to take here?

I think some pictures or drawing are needed to get any useful advice
ouf of the newsgroup. *Typically you build temporary walls or use jack
posts to take the load off. *In the case of the wall you would need to
build one or two temporary walls along it. *You may also need to nail
some cross pieces at the ends to keep it from falling thorugh when you
remove the 3x12 under it.

I do agree with some of the other posters, is it not possiel to repair
what you have? *Or are you trying to get an uninterrupted span where
I'm guessing there must be some posts holding up these 3x12s?

Thanks for all the replies. I didn't provide enough information, so
I'll to give some more here. Please let me know if were still missing
important bits!

The goal is not to repair, but to remove a column in the basement. I'd
like to have an uninterrupted span of 16 feet in the basement to use
as a family room.

The current situation is as follows: the beam is in 3 sections of 12
feet. It's currently supported by 3 columns: one at 8 feet, 16 feet
and 24 feet from the front wall. On the ground floor, the previous
owners made some modifications and removed part of the original load-
bearing wall. From the front wall: there is now a 4-feet section of
remaining wall, a 16 feet opening and 6.5 feet of wall. That opening
is supported by a steel beam with columns on either ends (approx 4
feet and 20 feet from the front wall).

Here's some amazing ASCII art that depicts the current situation. If
you look at this with a mono-spaced font (such as courier) it should
come out ok:

U *||||||||||||||||||||||||||
* * * *------------------
G *||||| * * * * * * * *|||||
* *===================----------------------
B || * * * *| * * * *| * * * *| * * * * * *||

- Legend -
U : Upper floor (roof left out)
G : Ground floor
B : Basement
- : existing beam
| : existing column
||: existing wall (load-bearing or foundation wall)
= : existing section of beam to be replaced

By replacing that section of beam, I can remove that first column and
only have a single one at 16 feet which is ok in regards to what's
around it.

I did look into another solution: move the 2 columns in the basement
directly under the columns on the ground floor: 4 feet and 20 feet.
Then place a re-enforcing steel plate to hold up the two sections of
wood beam. The engineer made those plans and made the specs of the
columns, footings and steel plate. The downside of this plan is that I
have to take down additional walls in the basement, the footings are
quite large (4x4x1) and I end up having 2 columns in the basement. So
I asked the engineer to look into a single-column solution to see if
this alternative plan is feasible and what are its downsides. I'll be
getting these plans in the next few days.

Obviously, I'll also be asking the engineer about how to support this
wall section and the floor joist. But I thought I could get some
insight here also.

The goal is to know how one goes about doing this before I call
contractors. I like being informed independently from the people that
will be doing the job, otherwise they could be doing some nasty stuff
and I wouldn't the wiser... I'm trying to stay out of trouble, not get
into it!

Some additional info:
House is located in very safe, non-seismic place of the world (lived
here 30 years, we've had 2 below 5)
No hurricanes or tornadoes have ever gone by
Ground is very dense
Neighbours are attached on both sides

Thanks for all the replies!
Phil- Hide quoted text -

- Show quoted text -

Support the floor joists with temporary walls or jack posts with beams
on top. Put a couple temporary walls on either side of the wall that
is on top of the 3x12. These can be pretty simple. Lag a couple
2x6's to the ends of the wall directly on top of the floor to support
it while the 3x12s are removed. It might hang from above but I
wouldn't take the chance. Remove the 3x12 and replace it. Since the
present beam is a 3x12 I'd also look at a 3x12 manufactured beam
instead of steel. It will be easier to reattach the floor joists.
And I suspect the manufactured beam can handle the 16' span. Your
engineer could tell you.

On Jun 22, 11:00*am, jamesgangnc wrote:
On Jun 22, 10:29*am, Phil wrote:



On Jun 22, 8:05*am, jamesgangnc wrote:

On Jun 21, 4:19*pm, Phil wrote:

Hi everyone,

I'm interested in knowing how one would go about replacing part of the
main beam (basement) of a 1926 house.

I've consulted a structural engineer to figure out the required size/
strength of the new beam (probably steel). He will also be specifying
the size of the required column and its footing. I'm currently trying
to figure out how the work can be accomplished and would appreciate
some input.

The beam to be replaced is made of 3 wooden 3x12. My issue is with the
fact that the floor joists are hanging from that beam (as opposed to
being supported by it). Sitting on this beam is also a 4-feet section
of a load-bearing wall.

I figured that I could support the floor joists with jack posts or
some temporary load-bearing wall on both sides of the existing beam,
but how can I support the 4-feet section of wall without being in the
way of the new beam to put in place?

Whatever I put in place there must be removed in order to put in the
new beam, but I can't put in the new beam without supporting that
wall... What kind of approach would you suggest to take here?

I think some pictures or drawing are needed to get any useful advice
ouf of the newsgroup. *Typically you build temporary walls or use jack
posts to take the load off. *In the case of the wall you would need to
build one or two temporary walls along it. *You may also need to nail
some cross pieces at the ends to keep it from falling thorugh when you
remove the 3x12 under it.

I do agree with some of the other posters, is it not possiel to repair
what you have? *Or are you trying to get an uninterrupted span where
I'm guessing there must be some posts holding up these 3x12s?

Thanks for all the replies. I didn't provide enough information, so
I'll to give some more here. Please let me know if were still missing
important bits!

The goal is not to repair, but to remove a column in the basement. I'd
like to have an uninterrupted span of 16 feet in the basement to use
as a family room.

The current situation is as follows: the beam is in 3 sections of 12
feet. It's currently supported by 3 columns: one at 8 feet, 16 feet
and 24 feet from the front wall. On the ground floor, the previous
owners made some modifications and removed part of the original load-
bearing wall. From the front wall: there is now a 4-feet section of
remaining wall, a 16 feet opening and 6.5 feet of wall. That opening
is supported by a steel beam with columns on either ends (approx 4
feet and 20 feet from the front wall).

Here's some amazing ASCII art that depicts the current situation. If
you look at this with a mono-spaced font (such as courier) it should
come out ok:

U *||||||||||||||||||||||||||
* * * *------------------
G *||||| * * * * * * * *|||||
* *===================----------------------
B || * * * *| * * * *| * * * *| * * * * * *||

- Legend -
U : Upper floor (roof left out)
G : Ground floor
B : Basement
- : existing beam
| : existing column
||: existing wall (load-bearing or foundation wall)
= : existing section of beam to be replaced

By replacing that section of beam, I can remove that first column and
only have a single one at 16 feet which is ok in regards to what's
around it.

I did look into another solution: move the 2 columns in the basement
directly under the columns on the ground floor: 4 feet and 20 feet.
Then place a re-enforcing steel plate to hold up the two sections of
wood beam. The engineer made those plans and made the specs of the
columns, footings and steel plate. The downside of this plan is that I
have to take down additional walls in the basement, the footings are
quite large (4x4x1) and I end up having 2 columns in the basement. So
I asked the engineer to look into a single-column solution to see if
this alternative plan is feasible and what are its downsides. I'll be
getting these plans in the next few days.

Obviously, I'll also be asking the engineer about how to support this
wall section and the floor joist. But I thought I could get some
insight here also.

The goal is to know how one goes about doing this before I call
contractors. I like being informed independently from the people that
will be doing the job, otherwise they could be doing some nasty stuff
and I wouldn't the wiser... I'm trying to stay out of trouble, not get
into it!

Some additional info:
House is located in very safe, non-seismic place of the world (lived
here 30 years, we've had 2 below 5)
No hurricanes or tornadoes have ever gone by
Ground is very dense
Neighbours are attached on both sides

Thanks for all the replies!
Phil- Hide quoted text -

- Show quoted text -

Support the floor joists with temporary walls or jack posts with beams
on top. *Put a couple temporary walls on either side of the wall that
is on top of the 3x12. *These can be pretty simple. *Lag a couple
2x6's to the ends of the wall directly on top of the floor to support
it while the 3x12s are removed. *It might hang from above but I
wouldn't take the chance. *Remove the 3x12 and replace it. *Since the
present beam is a 3x12 I'd also look at a 3x12 manufactured beam
instead of steel. *It will be easier to reattach the floor joists.
And I suspect the manufactured beam can handle the 16' span. *Your
engineer could tell you.

The current beam is 3 pieces of 3x12. I expect that the new beam will
be steel and that it will be 12 inches high to support the 16 feet
span. I don't know how wide it's going to be though (7 inches maybe?)

The current floor joists are attached to the current wood beam. That
is, the beam does not run *under* the joists; rather, the ends of the
joists are nailed to the beam. So if I remove the beam, there's
nothing directly under that 4 feet section of wall to support it.
That's what I'm trying to figure out: how do I support this wall while
I'm replacing the beam?

If the new beam is not as wide as the old one (say 7 inches instead of
9), I suppose I could use those 2 inches to support the wall on either
side. But an inch on either side seems pretty slim!

If the new beam is not as high (say 11 inches), then I thought I could
use some type of steel plate supported by jack posts on either side.
Then slide in the new beam and simply leave the steel plate there
after removing the posts.

Otherwise, I thought I'd need to raise the wall a little, but I'm not
sure I like this very much. Anybody do anything similar? What can I
expect by doing this?

Cheers,
Phil

Phil wrote:
....

The goal is not to repair, but to remove a column in the basement. I'd
like to have an uninterrupted span of 16 feet in the basement to use
as a family room.

....

Alternate suggestion -- instead of trying to replace the whole thing,
why not ask what it would take in a steel plate bolted alongside the
existing beam to get the span? (I'd guess 1/2" would do it, but I
didn't try any calc's, that's just gut feel).

That would only require supporting the floor joists on one side, cutting
them back to allow sliding in the (predrilled judiciously ) plate
bolting it through the beam and attaching the joists. If carefully
measured, you could even have the hangers welded in the proper locations
and simply attach the joists instead of both directions in place...

$0.02, etc., ...

On Jun 22, 11:00*am, jamesgangnc wrote:
On Jun 22, 10:29*am, Phil wrote:



On Jun 22, 8:05*am, jamesgangnc wrote:

On Jun 21, 4:19*pm, Phil wrote:

Hi everyone,

I'm interested in knowing how one would go about replacing part of the
main beam (basement) of a 1926 house.

I've consulted a structural engineer to figure out the required size/
strength of the new beam (probably steel). He will also be specifying
the size of the required column and its footing. I'm currently trying
to figure out how the work can be accomplished and would appreciate
some input.

The beam to be replaced is made of 3 wooden 3x12. My issue is with the
fact that the floor joists are hanging from that beam (as opposed to
being supported by it). Sitting on this beam is also a 4-feet section
of a load-bearing wall.

I figured that I could support the floor joists with jack posts or
some temporary load-bearing wall on both sides of the existing beam,
but how can I support the 4-feet section of wall without being in the
way of the new beam to put in place?

Whatever I put in place there must be removed in order to put in the
new beam, but I can't put in the new beam without supporting that
wall... What kind of approach would you suggest to take here?

I think some pictures or drawing are needed to get any useful advice
ouf of the newsgroup. *Typically you build temporary walls or use jack
posts to take the load off. *In the case of the wall you would need to
build one or two temporary walls along it. *You may also need to nail
some cross pieces at the ends to keep it from falling thorugh when you
remove the 3x12 under it.

I do agree with some of the other posters, is it not possiel to repair
what you have? *Or are you trying to get an uninterrupted span where
I'm guessing there must be some posts holding up these 3x12s?

Thanks for all the replies. I didn't provide enough information, so
I'll to give some more here. Please let me know if were still missing
important bits!

The goal is not to repair, but to remove a column in the basement. I'd
like to have an uninterrupted span of 16 feet in the basement to use
as a family room.

The current situation is as follows: the beam is in 3 sections of 12
feet. It's currently supported by 3 columns: one at 8 feet, 16 feet
and 24 feet from the front wall. On the ground floor, the previous
owners made some modifications and removed part of the original load-
bearing wall. From the front wall: there is now a 4-feet section of
remaining wall, a 16 feet opening and 6.5 feet of wall. That opening
is supported by a steel beam with columns on either ends (approx 4
feet and 20 feet from the front wall).

Here's some amazing ASCII art that depicts the current situation. If
you look at this with a mono-spaced font (such as courier) it should
come out ok:

U *||||||||||||||||||||||||||
* * * *------------------
G *||||| * * * * * * * *|||||
* *===================----------------------
B || * * * *| * * * *| * * * *| * * * * * *||

- Legend -
U : Upper floor (roof left out)
G : Ground floor
B : Basement
- : existing beam
| : existing column
||: existing wall (load-bearing or foundation wall)
= : existing section of beam to be replaced

By replacing that section of beam, I can remove that first column and
only have a single one at 16 feet which is ok in regards to what's
around it.

I did look into another solution: move the 2 columns in the basement
directly under the columns on the ground floor: 4 feet and 20 feet.
Then place a re-enforcing steel plate to hold up the two sections of
wood beam. The engineer made those plans and made the specs of the
columns, footings and steel plate. The downside of this plan is that I
have to take down additional walls in the basement, the footings are
quite large (4x4x1) and I end up having 2 columns in the basement. So
I asked the engineer to look into a single-column solution to see if
this alternative plan is feasible and what are its downsides. I'll be
getting these plans in the next few days.

Obviously, I'll also be asking the engineer about how to support this
wall section and the floor joist. But I thought I could get some
insight here also.

The goal is to know how one goes about doing this before I call
contractors. I like being informed independently from the people that
will be doing the job, otherwise they could be doing some nasty stuff
and I wouldn't the wiser... I'm trying to stay out of trouble, not get
into it!

Some additional info:
House is located in very safe, non-seismic place of the world (lived
here 30 years, we've had 2 below 5)
No hurricanes or tornadoes have ever gone by
Ground is very dense
Neighbours are attached on both sides

Thanks for all the replies!
Phil- Hide quoted text -

- Show quoted text -

Support the floor joists with temporary walls or jack posts with beams
on top. *Put a couple temporary walls on either side of the wall that
is on top of the 3x12. *These can be pretty simple. *Lag a couple
2x6's to the ends of the wall directly on top of the floor to support
it while the 3x12s are removed. *It might hang from above but I
wouldn't take the chance. *Remove the 3x12 and replace it. *Since the
present beam is a 3x12 I'd also look at a 3x12 manufactured beam
instead of steel. *It will be easier to reattach the floor joists.
And I suspect the manufactured beam can handle the 16' span. *Your
engineer could tell you.

I just realized I misunderstood your solution.

So you're proposing to support the ground-floor wall from the ground
floor itself. Interesting. This moves the weight of the wall on either
side which would be supported by the temporary walls (or posts) in the
basement.

There's a column in that wall that supports a 16 feet beam in the
ceiling there. I suppose that means that I'd have to support that beam
in a similar way, by making some temp walls on the ground floor that
would support this beam (and, while were at it the 4-feet section of
wall).

Could I support the 4-feet wall from its top instead of its ends? The
reason is that one end is not very reachable and the other is
obstructed by the column supporting the beam.

Cheers,
Phil

On Jun 22, 11:38*am, dpb wrote:
Phil wrote:

...

The goal is not to repair, but to remove a column in the basement. I'd
like to have an uninterrupted span of 16 feet in the basement to use
as a family room.

...

Alternate suggestion -- instead of trying to replace the whole thing,
why not ask what it would take in a steel plate bolted alongside the
existing beam to get the span? *(I'd guess 1/2" would do it, but I
didn't try any calc's, that's just gut feel).

That would only require supporting the floor joists on one side, cutting
them back to allow sliding in the (predrilled judiciously ) plate
bolting it through the beam and attaching the joists. *If carefully
measured, you could even have the hangers welded in the proper locations
and simply attach the joists instead of both directions in place...

$0.02, etc., ...

That's Plan A, or close to it at least. The steel plate has been
speced-out and requires some, as you say, judiciously placed brackets
for the joists. The downside is that the engineer didn't seem to think
that I could get the 16 feet span using this. When we discussed this
plan, we immediatly thought we needed to place the basement columns
under the gound-floor columns to get proper support. You're right
though, I should get him to check if we can get a 16 feet span using
the steel plates solution.

Thanks!
Phil

Phil wrote:
On Jun 22, 11:38 am, dpb wrote:
....

Alternate suggestion -- instead of trying to replace the whole thing,
why not ask what it would take in a steel plate bolted alongside the
existing beam to get the span? (I'd guess 1/2" would do it, but I
didn't try any calc's, that's just gut feel).
....

That's Plan A, or close to it at least. The steel plate has been
speced-out and requires some, as you say, judiciously placed brackets
for the joists. The downside is that the engineer didn't seem to think
that I could get the 16 feet span using this. When we discussed this
plan, we immediatly thought we needed to place the basement columns
under the gound-floor columns to get proper support. You're right
though, I should get him to check if we can get a 16 feet span using
the steel plates solution.
....

I'm having hard time thinking that's not feasible/adequate unless
there's a lot more going on here than a simple two-story. What's he say
is the limiting criterion, deflection or loading (stress)?

But, if the engineer's convinced the plate alone isn't enough, have a
lower flange welded to it -- either a wide leg angle or T. In essence a
channel w/o the upper flange that you really don't have need for.

In the extreme, one could even go the "U" but that would surely seem
overkill (again unles....).

W/O actual loadings, drawings, etc., hard to say.

--

I'm having hard time thinking that's not feasible/adequate unless
there's a lot more going on here than a simple two-story. *What's he say
is the limiting criterion, deflection or loading (stress)?

We actually did not discuss the possibility of a 16 feet span with
steel plates only. So I can't say what his opinion is. But based on
his proposed solution, I figured he didn't think it was possible. I'll
have to chat with him to know for sure.


But, if the engineer's convinced the plate alone isn't enough, have a
lower flange welded to it -- either a wide leg angle or T. *In essence a
channel w/o the upper flange that you really don't have need for.

In the extreme, one could even go the "U" but that would surely seem
overkill (again unles....).

His proposed solution *is* a steel U. 40 inches long with 9 blots on
both ends. He says that a U is required due to the compression
constraints on top of the beam and the tension constraints on the
bottom. He seems to think that simply putting in plates is not
sufficient for proper support.

Keep in mind that the engineer is going with the safest solution here.
So it's probably somewhat overkill.


W/O actual loadings, drawings, etc., hard to say.

--

His proposed solution states that the columns (one a 4.5 feet and one
at 19.5 feet) both require material to support 25 000 pounds. So he
speced the columns as 5.25x5.5 PSL.

What other loads would you need to have a better idea? I can ask him
to give me the values.

It's true though that if the second column is at 16 feet instead of
20, then the first column might not be required if the steel U is
strong enough. I should've thought about that earlier!

Thanks again,
Phil

Phil wrote:
Hi everyone,

I'm interested in knowing how one would go about replacing part of the
main beam (basement) of a 1926 house.

I've consulted a structural engineer to figure out the required size/
strength of the new beam (probably steel). He will also be specifying
the size of the required column and its footing. I'm currently trying
to figure out how the work can be accomplished and would appreciate
some input.

The beam to be replaced is made of 3 wooden 3x12. My issue is with the
fact that the floor joists are hanging from that beam (as opposed to
being supported by it). Sitting on this beam is also a 4-feet section
of a load-bearing wall.

I figured that I could support the floor joists with jack posts or
some temporary load-bearing wall on both sides of the existing beam,
but how can I support the 4-feet section of wall without being in the
way of the new beam to put in place?

Whatever I put in place there must be removed in order to put in the
new beam, but I can't put in the new beam without supporting that
wall... What kind of approach would you suggest to take here?

Call a house mover. How would they support it for moving?



--
LSMFT

I haven't spoken to my wife in 18 months.
I don't like to interrupt her.

On Jun 21, 3:19*pm, Phil wrote:
Hi everyone,

I'm interested in knowing how one would go about replacing part of the
main beam (basement) of a 1926 house.

I've consulted a structural engineer to figure out the required size/
strength of the new beam (probably steel). He will also be specifying
the size of the required column and its footing. I'm currently trying
to figure out how the work can be accomplished and would appreciate
some input.

The beam to be replaced is made of 3 wooden 3x12. My issue is with the
fact that the floor joists are hanging from that beam (as opposed to
being supported by it). Sitting on this beam is also a 4-feet section
of a load-bearing wall.

I figured that I could support the floor joists with jack posts or
some temporary load-bearing wall on both sides of the existing beam,
but how can I support the 4-feet section of wall without being in the
way of the new beam to put in place?

Whatever I put in place there must be removed in order to put in the
new beam, but I can't put in the new beam without supporting that
wall... What kind of approach would you suggest to take here?

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.

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
decision.

Thanks for your comment.
Phil

Phil wrote:
I'm having hard time thinking that's not feasible/adequate unless
there's a lot more going on here than a simple two-story. What's he say
is the limiting criterion, deflection or loading (stress)?

....

In the extreme, one could even go the "U" but that would surely seem
overkill (again unles....).

His proposed solution *is* a steel U. 40 inches long with 9 blots on
both ends. He says that a U is required due to the compression
constraints on top of the beam and the tension constraints on the
bottom. He seems to think that simply putting in plates is not
sufficient for proper support.

Well, I'm confused... what's 40"???

Keep in mind that the engineer is going with the safest solution here.
So it's probably somewhat overkill.

Well, he ought to be making something adequate but minimal to do the
job, not over-designing; that's not engineering.

W/O actual loadings, drawings, etc., hard to say.

--

His proposed solution states that the columns (one a 4.5 feet and one
at 19.5 feet) both require material to support 25 000 pounds. So he
speced the columns as 5.25x5.5 PSL.

What other loads would you need to have a better idea? I can ask him
to give me the values.

It's true though that if the second column is at 16 feet instead of
20, then the first column might not be required if the steel U is
strong enough. I should've thought about that earlier!
....

I'm totally confused now -- where did the 20' span come from? Your
objective stated up top was a 16-ft clear span for a family room. Yes,
a 20-ft span is going to cause the requirements to go up quadratically
to a first approximation on deflection which would be ~1.5X and linearly
on stress, though.

Oh, OK, I went back to your drawing and sketched it out on paper w/
dimensions. I see what he did was to automatically place his columns
under the upstairs walls to get the direct support transmitted
vertically. That's kewl...but what strikes me is that he doesn't need
additional beam to transmit that (locally distributed) point load; the
existing beam is (apprently) doing that fine w/o crushing so it will
continue to do so.

It would seem the only real function the additional structural member
has to do is to handle the distributed load across the longer gap which
shouldn't be that great it would seem.

It almost sounds like he's discounting the existing beam entirely owing,
I suppose, to the point I didn't catch early on of it being a 12-ft run
on 8-ft supports. I'm not going to second-guess the guy but I'd wonder
if it really is needed to actually get that full U section under the
existing beam at the outside end.

I see w/ that location of the two columns you do have roughly the 16-ft
open space; I'm just surprised since the bulk of the loading is on the
ends instead of distributed it requires so much heft. What's the
dimension on the U he's given, including thicknesses?

To do any calculation would require knowing all the loads assumed,
live/dead/additional code-required for the jurisdiction, etc. They
ought to be on the design documents if you have access to those but if
all you've contracted for is a design, that may not be part of the deal.

As others noted, it would be possible to rig up ways to get it there but
it does just seem pretty stout for the application from afar and w/o
actually doing any real numerics, of course...

--

On Jun 22, 1:50*pm, dpb wrote:
Oh, OK, I went back to your drawing and sketched it out on paper w/
dimensions. *I see what he did was to automatically place his columns
under the upstairs walls to get the direct support transmitted
vertically. *That's kewl...but what strikes me is that he doesn't need
additional beam to transmit that (locally distributed) point load; the
existing beam is (apprently) doing that fine w/o crushing so it will
continue to do so.

Yes, moving the columns under the ones from the ground floor was
automatically considered. Turns out that the required footing is much
larger than I had expected, so I have to tear down a whole lot more
basement for this solution. This is why I'm looking for alternatives.

It would seem the only real function the additional structural member
has to do is to handle the distributed load across the longer gap which
shouldn't be that great it would seem.

The additional member here is the steel piece?

It almost sounds like he's discounting the existing beam entirely owing,
I suppose, to the point I didn't catch early on of it being a 12-ft run
on 8-ft supports. *I'm not going to second-guess the guy but I'd wonder
if it really is needed to actually get that full U section under the
existing beam at the outside end.

I see w/ that location of the two columns you do have roughly the 16-ft
open space; I'm just surprised since the bulk of the loading is on the
ends instead of distributed it requires so much heft. *What's the
dimension on the U he's given, including thicknesses?

So, the proposed steel piece is a U: its legs are 10 inches high, the
base is 9 inches wide and would run along 40 inches of the beam. It's
1/4 inch thick.

Since the beam is made of 3 sections of 12 feet, this piece is there
only to support the connection of 2 of those sections. The steel piece
would cover 20 inches on both sides of the split.

In my mind, the proposed columns (at 4.5 feet and 20 feet) are doing
all the work really since they're directly below the ones on the
ground floor.

I asked him to look into another solution that has only one column at
16 feet (instead of 2: one at 4 and 20). The reason is that this 16
feet span would better suit what's around it: more specifically, the
staircase. As mentioned above, a single column would have less impact
due to the size of the required footing.


To do any calculation would require knowing all the loads assumed,
live/dead/additional code-required for the jurisdiction, etc. *They
ought to be on the design documents if you have access to those but if
all you've contracted for is a design, that may not be part of the deal.

Yes, the codes are on the drawing, but not the assumed loads. I can
get him to add these numbers I suppose.

I understand all the complexities involved here, so I'm not looking
for formal advice: that's why the engineer is working for me.

In your mind, a 16 feet span with steel support around the split at 12
feet, a proper column at 16 feet, w/ proper footing *could* handle
this? Again, not looking for formal advice, here, I just want to steer
my engineer in the proper direction. They don't come cheap!


As others noted, it would be possible to rig up ways to get it there but
it does just seem pretty stout for the application from afar and w/o
actually doing any real numerics, of course...

--

Yeah. Seems like a much larger job than I really expected...

Phil wrote:
On Jun 22, 1:50 pm, dpb wrote:
....

It would seem the only real function the additional structural member
has to do is to handle the distributed load across the longer gap which
shouldn't be that great it would seem.

The additional member here is the steel piece?

Yes, see below for more on that...

....

I see w/ that location of the two columns you do have roughly the 16-ft
open space; I'm just surprised since the bulk of the loading is on the
ends instead of distributed it requires so much heft. What's the
dimension on the U he's given, including thicknesses?

So, the proposed steel piece is a U: its legs are 10 inches high, the
base is 9 inches wide and would run along 40 inches of the beam. It's
1/4 inch thick.

Since the beam is made of 3 sections of 12 feet, this piece is there
only to support the connection of 2 of those sections. The steel piece
would cover 20 inches on both sides of the split.

In my mind, the proposed columns (at 4.5 feet and 20 feet) are doing
all the work really since they're directly below the ones on the
ground floor.

Indeed, that's where I was confused before...I had misunderstood and
thought this U was the full-length beam replacement and were trying to
figure out how to get it in place on one end. I couldn't figure out
how, since the main load was, as you say being carried by the columns
one needed anything anyways near that stout as the intermediate beam
between them. That it's a gusset plate I can go with at the dimensions.

But, that leaves me w/ the problem of not understanding what's the issue
in the installation I think.

I asked him to look into another solution that has only one column at
16 feet (instead of 2: one at 4 and 20). The reason is that this 16
feet span would better suit what's around it: more specifically, the
staircase. As mentioned above, a single column would have less impact
due to the size of the required footing.

....

In your mind, a 16 feet span with steel support around the split at 12
feet, a proper column at 16 feet, w/ proper footing *could* handle
this? Again, not looking for formal advice, here, I just want to steer
my engineer in the proper direction. They don't come cheap!

No, I don't think that would work; what I was envisioning was a full
length side plate of (say) 1/2" x 10" bolted thru the existing beam to
handle the longer span w/ the upstairs load handled by the columns.

I thought your original proposal was to replace the existing beam in its
entirety and my suggestion was to leave it in place and rather than put
something underneath it over the existing column to trim the joists and
rehang them leaving the vertical primary support on the column.

I think there's still some talking past each other owing to each having
a vision but not a common set of drawings/concepts...

....

Yeah. Seems like a much larger job than I really expected...

Always is when get an engineer involved...

Altho I commend you for getting somebody to actually look at the
situation given the nontrivial nature of the loading distributions and
particularly that discontinuous beam that complicates things.

Good luck; knowing the guy didn't try to fit in a full-length U to
bridge the gap and claim it had a stress problem makes me feel much
better about his doings...I believe it for the 1/4"T short section to
hold the end moments; I wasn't so sure when presumed it was much heavier
material and full length. vbg

--

On Jun 22, 2:48*pm, dpb wrote:
I think there's still some talking past each other owing to each having
a vision but not a common set of drawings/concepts...

Yes, the main confusion comes from the fact that my original question
was not about this plan. I was asking about a different plan that I'm
considering due to the problems with this solution.

Plan 1: 2 columns (4 and 20 feet) under ground-floor columns with
steel U supporting the beam's gap
Plan 2: single column @ 16 feet with beam replacement. (this post was
about this plan)

Ideally, I'd have a single column @ 16 feet, but this doesn't seem
possible without replacing the beam.

Thanks again,
Phil

On Jun 22, 3:22*pm, Phil wrote:
On Jun 22, 2:48*pm, dpb wrote:

I think there's still some talking past each other owing to each having
a vision but not a common set of drawings/concepts...

Yes, the main confusion comes from the fact that my original question
was not about this plan. I was asking about a different plan that I'm
considering due to the problems with this solution.

Plan 1: 2 columns (4 and 20 feet) under ground-floor columns with
steel U supporting the beam's gap
Plan 2: single column @ 16 feet with beam replacement. (this post was
about this plan)

Ideally, I'd have a single column @ 16 feet, but this doesn't seem
possible without replacing the beam.

Thanks again,
Phil

What's the distance in the other directions, aka 90 deg from your
beam. Is it possible to put a smaller steel I beam 90 deg in place of
the column you want to remove?

On Jun 22, 3:34*pm, jamesgangnc wrote:
What's the distance in the other directions, aka 90 deg from your
beam. *Is it possible to put a smaller steel I beam 90 deg in place of
the column you want to remove?

Interesting thought!

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?

Thanks,
Phil

On Jun 22, 3:43*pm, Phil wrote:
On Jun 22, 3:34*pm, jamesgangnc wrote:

What's the distance in the other directions, aka 90 deg from your
beam. *Is it possible to put a smaller steel I beam 90 deg in place of
the column you want to remove?

Interesting thought!

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?

Thanks,
Phil

Yea, but I was hoping for a shorter distance :-) Oh Well.

On 2010-06-22, Phil wrote:

Plan 1: 2 columns (4 and 20 feet) under ground-floor columns with
steel U supporting the beam's gap

Plan 2: single column @ 16 feet with beam replacement. (this post was
about this plan)

[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
flitch plates.

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.

Cheers, Wayne

Wayne Whitney wrote:
On 2010-06-22, Phil wrote:

Plan 1: 2 columns (4 and 20 feet) under ground-floor columns with
steel U supporting the beam's gap

Plan 2: single column @ 16 feet with beam replacement. (this post was
about this plan)

[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
flitch plates.

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)...

--

On Jun 22, 9:12*am, dpb wrote:
Phil wrote:
On Jun 22, 11:38 am, dpb wrote:

...

Alternate suggestion -- instead of trying to replace the whole thing,
why not ask what it would take in a steel plate bolted alongside the
existing beam to get the span? *(I'd guess 1/2" would do it, but I
didn't try any calc's, that's just gut feel).

...

That's Plan A, or close to it at least. The steel plate has been
speced-out and requires some, as you say, judiciously placed brackets
for the joists. The downside is that the engineer didn't seem to think
that I could get the 16 feet span using this. When we discussed this
plan, we immediatly thought we needed to place the basement columns
under the gound-floor columns to get proper support. You're right
though, I should get him to check if we can get a 16 feet span using
the steel plates solution.

...

I'm having hard time thinking that's not feasible/adequate unless
there's a lot more going on here than a simple two-story. *What's he say
is the limiting criterion, deflection or loading (stress)?

But, if the engineer's convinced the plate alone isn't enough, have a
lower flange welded to it -- either a wide leg angle or T. *In essence a
channel w/o the upper flange that you really don't have need for.

In the extreme, one could even go the "U" but that would surely seem
overkill (again unles....).

W/O actual loadings, drawings, etc., hard to say.

--

dpb-

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.

OP-
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?

cheers
Bob

On Tue, 22 Jun 2010 07:29:33 -0700 (PDT), Phil
wrote:


Obviously, I'll also be asking the engineer about how to support this
wall section and the floor joist. But I thought I could get some
insight here also.


The goal is to know how one goes about doing this before I call
contractors. I like being informed independently from the people that
will be doing the job, otherwise they could be doing some nasty stuff
and I wouldn't the wiser... I'm trying to stay out of trouble, not get
into it!

Huh????

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
job???

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.

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:
http://www.jlconline.com/cgi-bin/jlc...8259467c07&p=1


Here is one other approach:
http://www.jlconline.com/cgi-bin/jlc...03ef3ea2b6&p=1

Here is another, though you may have to pay to access the archive
http://www.jlconline.com/cgi-bin/jlc.../View/9712repl

--
~~~~~~~~~~~~~~~~~~~~
DanG
Keep the whole world singing . . .


"Phil" wrote in message
...
Hi everyone,

I'm interested in knowing how one would go about replacing part
of the
main beam (basement) of a 1926 house.

I've consulted a structural engineer to figure out the required
size/
strength of the new beam (probably steel). He will also be
specifying
the size of the required column and its footing. I'm currently
trying
to figure out how the work can be accomplished and would
appreciate
some input.

The beam to be replaced is made of 3 wooden 3x12. My issue is
with the
fact that the floor joists are hanging from that beam (as
opposed to
being supported by it). Sitting on this beam is also a 4-feet
section
of a load-bearing wall.

I figured that I could support the floor joists with jack posts
or
some temporary load-bearing wall on both sides of the existing
beam,
but how can I support the 4-feet section of wall without being
in the
way of the new beam to put in place?

Whatever I put in place there must be removed in order to put in
the
new beam, but I can't put in the new beam without supporting
that
wall... What kind of approach would you suggest to take here?

On Jun 23, 2:07 am, wrote:
Either trust your engineer, or hire a second one as a double check.

I was referring to the contractor, not the engineer.

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.

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.

Cheers,
Phil

On Jun 23, 11:11*am, "DanG" wrote:
If you intend to remove the existing woodbeam, you will need to
build a temporary wall on each side of thebeamthat will carry
the load while you remove and replace. *Getting abeamof 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:http://www.jlconline.com/cgi-bin/jlc...c21ccb012c0f6d...

Here is one other approach:http://www.jlconline.com/cgi-bin/jlc...c21ccb012c0f6d...

Here is another, though you may have to pay to access the archivehttp://www.jlconline.com/cgi-bin/jlconline.storefront/4c21ccb012c0f6d...


Thanks! This is great stuff! Didn't know about JLC.

Cheers,
Phil

On Jun 23, 12:23*am, DD_BobK wrote:
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.

OP-
You didn't give the exact dims of the 3x12's (true 12" or 11.25"?) *or
the depth of the joists (2x8's?)

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
everything yet).

I did measure the joists, but can't remember off the top of my head. I
think they're 2x12.

but my rough calc says that plates (1/2" x 12") both sides should
just about do the trick.

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
split?

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
ends.


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.

Interesting, I'll see what he has to say about this.

How about some photos?

I'll see what I can do.

Thanks!
Phil