Support... or lack thereof

Specific Inspection Topics Structural Inspections
41

Would it not be as simple as reccommending to have the othe half of the adjustable post installed?

Agreeing that two 2"x4" post will not match the support capacities of the adjustable column, a continuous stud wall under a support beam for a house would not be a problem.

Weight distribution and load capacities of a stud wall construction under the beam would be no different than load capacities required to hold up roof rafters or trusses.

Concrete floor depression requirement, give me a break, that is commercial where loads wayyyyyy exceed that of a residential load.

Residential concrete= minimum of 2500 psi.
Load design= 40 psi at best

Do the math. ha. ha.

Marcel :slight_smile: :slight_smile:

42

Marcel

So just to add to the confusion… why not frame the wall with 2x6 and bottom plate, that should spread the loader gooder, eh? :wink:

43

I agree Raymond, but just trying to find a happy medium to the resolve of this debate. ha. ha.
Either or would work.

Marcel :slight_smile: :slight_smile:

44

Well, don’t do the math based on those figures, because I’m sure Marcel meant to say 40 psF. :slight_smile:

45

The load from the beam goes exactly to where it went before the steel post was removed, and the 2 2x4 studs are very likely quite adequate to support the load and transmit it to the very same footing which supported the steel post. Yes, a steel post, if pushed to its limit, will likely be capable of supporting more load than two spaced wood posts, but if the loads ever approached that limit, then there are probably many other severe structural problems in the house. Would I be happier if those two studs were tied together? Sure. But it is very possible that even just one of the studs would be capable of supporting the actual design loads in the example.

In order for the other studs to carry any load at all, the beam would have to deflect excessively between its original supports. If the beam was properly designed, it will not do so. Therefore, a continuous footing under the beam is not necessary and would serve no purpose.

Nevertheless, if I were an inspector, I would refer the situation to a structural engineer, who is licensed and presumably qualified to make an accurate assessment.

46

Thanks for the correction Richard, it would make a difference wouldn’t it? ha. ha.

At least I conveyed the message. :wink:

Marcel :slight_smile:

47

Its the mid span support that is in question. It has been removed temporarily or permanently. The meagre 2x4 studs are not meant to carry the load mid span. The stud on the left looks like it has a bow in it.

48

Ray; having multiple studs, would that not eliminate mid span support and distribute it accordingly?

Would not the concentrated span load on one steel column be dispersed equally among the sharing load studs?

Just a thought. :slight_smile:

Marcel :slight_smile:
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49

Really, the way the steel post is disassembled, it appears to be a telescopic adjustable column that is not approved for use as a permanent support. So, that may be why it was removed and studs infilled.

50

You are right Larry, remember this?

http://www.octoberhome.com/articles/adjustcolumn/adjustcolumn.html

Marcel :slight_smile: :wink:

51

Yes, thank you…my filing of links system is lacking sometimes. :smiley:

52

Marcel … building interior basement bearing walls without a thickened slab section for support … I am surprised you would even consider that. And yes, I have seen them crack typical 4,000 psi basement slabs without a thickened section.

For some example requirements see IRC R403.1 for typical interior bearing wall foundation support … and the figure which specifically shows the required thickened slab section below an interior bearing wall, which needs to be a minimum of 6" thicker than the slab (width depends on the soils). The requirements are in the IRC model code for a reason … :wink:

JMO

53

I concur with this part of Richard’s response because, really, it is still a beam with center bearing and infilled studs. JMO:D

54

I agree Robert, but in this residential building that I see around me, I have yet to see or will see someone that has constructed a slab with bearing walls that would meet this criteria.

The question is will the continuous 2"x4" stud wall bearing on an assumed 4" thick concrete floor replace the capacities of that adjustable jack? Yes.

Architectureally and Engineering concept, no.

This is a residential home of a small magnitude of the necessary designs required to necessitate engineering concepts as you and I are accustomed too would be overlay exaggerated.

This is an existing house, and do you expect that it can be corrected to meet the existing codes and structural capacities of the Engineering World.
The answer is no.

The solution is to recommend further evaluation.

What will the further evaluation unveil is the question?

Well, for starters,
The partition should have a depressed slab. Fine and dandy, but will not happen.

The bearing partition should be framed with a minimum of 2"x6" framing members spaced no more than 24" o.c…

The bearing partion should be framed with a minimum of 2"x4" spaced at 16" o. c. maximum members with double plates at the top bearing and Pressure treated lumber sole plate in contact with concrete.
Most likely will not happen.

Adjustable lally columns are temporary supports anyways, but at the very least could be re-installed.

Is there a 2’x2’ x 10" thick footing under that column? Who knows.

Is the slab bearing on soil capacities of Group IV or Group I of the IRC?

So many unknowns.

What will the Engineer say after seeing all this, would be my question.

Assume that the subsoil meets Group I and assume the slab is of 3000 psi mix and assume their is a 1.4x1.4 x6x6 wire mesh and no depression.
Assume that it is only one story.

That stud wall would be more than necessary.

Is it right? No.

Was it right? No

So how would you assess it?

You think a Contractor could resolve this? No
You think a Contractor could fix. Yes with lots of money. ha. ha.

So you see there is no easy solution or answer to something so simple as supplementing what is missing with the equivalent.

Marcel :slight_smile: :slight_smile:

55

Et voila!

56

Why not simply recommend replacing that telepost…no need for a structural engineer here in my opinion.

57

MArcel,
You win!
Actually the inner part is inside the outer part and in embedded into the concrete at the base. It was part of the original construction. It was allowed to be used as a permanent post at the time of construction.
Larry, as you state there are a lot of invisibles under the concrete, however the buiolding inspector for the town would be responsible for this.
The only thing that needs to be done is the replacement of the pin and the adjustor on the top (the adjustor was there , but not the pin.)
And any home inspector that does not call this type of a defect would be very deelict in his duty.

58

That sectional post to my knowledge is permitted by building officials, because I see it time and time again in homes supposedly inspected and issued a occupancy permit fwiw.

59

But it is NOT a bearing partition. The beam above it still spans the same distance that it did when it was supported by the steel post, only now it is supported at that location by two wood studs instead. There is absolutely no need for a depressed slab footing.

60

Marcel … Just because something isn’t usually done correctly in a certain locality, or a client doesn’t follow a recommendation, doesn’t make it right or acceptable. Home inspectors should use industry accepted construction standards (like the IRC as an example) as a general guide, and if things are not done correctly it should get flagged.

From an HI point of view I dont agree. I have seen that situation crack 3"-4" slabs with good concrete from first hand experience … and why I mentioned that the IRC requirements for a thickened slab section under bearing walls is there for a reason. And it is a big leap of faith to assume the slab is a solid 4" thick. If there are no slab bearing walls many builders do not pay much attention to basement slabs, and sometimes I see them as thin as 1-1/2" to 2" thick.

What I would do as an engineer to evaluate the situation is completely different from what an HI is doing and should recommend.

Again, the two 2x4 studs (say about 2,000# to 4,000# capacity) cant even come close to replacing a typical steel column (say 15,000# - 30,000# capacity). Just to give some example numbers for discussion … say its a typical 25’ wide two story house. The load on a basement center bearing wall can be about 1,200 #/ft to 1,500 #/ft (even more for a posted roof ridge). If the columns are even closely spaced at 10’ to 12’ apart the column loads could be 15,000# to 20,000# … 25,000# to 30,000# for larger column spacing. Many dont realize how quickly loads can add up even in residential construction.

I think the bottom line for an HI is DONT GUESS OR MAKE ASSUMPTIONS with things like loads, capacity, supports, footings, slab thickness, etc … “Observe and Report” … and if you see something unusual, or something that looks wrong, just flag it and move on.

There is a reason that the highest liability area for an HI is the Structure, partly because things are not as simple as they may appear on the surface.

JMO & 2-nickels … :wink: