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Discussion Starter #1
Do support a sagging beam in my basement, I am required to pour 2 -24 x 24 x 12 inch square footers. I have done the laborious work and have dug them out.

I need to schedule the BI to come out and look at them before pouring so I have a few questions:

Currently I just have a square cutout with dirt sides and a dirt floor, even though it is in the correct dimensions. I am unfamiliar with concrete work and would like advice on how to set up a "form". Also, the current slab I have poured in my basement is a bit unlevel. The new footer has to be perfectly level, so how could I achieve this?

I looked online and was having some difficultly finding information on this other than people asking for what size they needed, which I already have from the SE.

Thanks in advance.

Tom
 

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IF your slab is level and your footer has to be perfectly level then you need to extend the height of your footer above the height of the floor. to do this you will need to make forms. If you dont need to extend it past the top of the concrete then earth forming a footer should be find assuming you have the proper compaction. That is a question for your inspector though.

How far out of level are you? I'm not sure what your tolerances are but in most places you can use non shrink grout under a base plate to level up to 1/4". Or a lot of structural systems you can use a leveling plate. I think that you will find that very few footers are perfectly level.
 

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tommy, just nail some 1x4's together to form a box 24" x 24",,, put those into the holes for a snug fit - place a level on top of the forms & tap til the little bubble's in the ctr of the marks on the level's sight glass - that will achieve your goal of having these new footers perfectly level :thumbup:

i'm sure the information's someplace on the i-net but most people own & know how to use levels by the time they own a home :laughing: no steel in your footers ?down here we use 2 mats of # 4 bar - ea mat at 90* to the other & 1/3rd & 2/3rds vertical evenly spaced horizontally :thumbsup:
 

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tommy, just nail some 1x4's together to form a box 24" x 24",,, put those into the holes for a snug fit - place a level on top of the forms & tap til the little bubble's in the ctr of the marks on the level's sight glass - that will achieve your goal of having these new footers perfectly level :thumbup:

i'm sure the information's someplace on the i-net but most people own & know how to use levels by the time they own a home :laughing: no steel in your footers ?down here we use 2 mats of # 4 bar - ea mat at 90* to the other & 1/3rd & 2/3rds vertical evenly spaced horizontally :thumbsup:
Make sure your building inspector and engineer of record are ok with you having a 22.5" x 22.5" footer for the first 3.5".
 

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Discussion Starter #6
The engineers specs did not call for any steel actually. I will double check but I did not see it. When pulling the permit they did not question it either.

Although these questions may seem elementary, I appreciate you guys answering them. Again, I have very very little experience with concrete but am attempting to use this as an opportunity to gain some.

The other question I have is when I remove the forms, I will have a 1x space that has no concrete. I would have had to cut through the slab to get my forms in place if I am understanding you correctly. What is to be done with this area?

Also, it is an unfinished basement and always will be. Am I able to put in a raised footer? As I mentioned earlier my slab is unlevel (sagging in the middle due to no footer under center pier). What is the proper way to do this? One part will have to be either under or over the current slab "line".

Thanks,

Tom
 

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experience is doing something correctly while ' lessons ' are gain'd from f'ing up :yes: being from camden is no excuse :no: after removing the forms, fill that space w/mortar,,, i'd think you could have a raised footer,,, by "line" you mean elevation ( height of finished top ) of the 2 ? ? ?
 

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Discussion Starter #8
Already have had too many lessons in this house, don't need another one (see my project thread, haha).

Also, Camden County is a big county. If I was from Camden, do you think you would still be alive after a comment like that? I mean, I know you are from the ATL but still...

Thanks and I will let you know how it goes...and so I am clear by "mortar" you are referring to the cement mix that I am using or a totally different animal?
 

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wuz in nj for 8yrs - otherwise i wouldn't have learnt to wear unlaced work boots :laughing: i'd use leftover conc mix & strain out some rock ( small crushed stone ) IF it were my bsmt,,, some of the pther ' purists ' may disagree but they don't know my bride, nagzilla :eek:
 

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if I understand your post correctly you are required to install 24" wide x24" long x12" deep footings to provide proper bearing for a column to support the beam, is this correct? if you have a dirt floor in the basement and not a concrete slab I'd just dig a square hole that is 24" x 24" to a depth of 12" and place the concrete in the hole up to the top of the hole. no form work needed.

I'd probably use 2-#5 rebars in each direction in the bottom of the hole (3" up from the dirt bottom) put a brick under the bars. won't hurt.

Should you desire to place a concrete floor in the basement in the future you would not have the footing in the way.

Just my humble thoughts, many ways to accomplish the same goal. Good luck!
 

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Discussion Starter #11
GBrack - I have a concrete slab. 2 inches thick, unlevel. But yes, your understanding of the issue is correct.

Thanks,

Tom
 

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cut out the slab to size and then dig 12" below the bottom of the concrete slab, still no form work. place concrete for footing up to bottom of slab. once column is installed use grout to fill in the area of the slab you cut out, this will lock in the base of the column.
 

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It would be better to dig the hole deep enough so the entirety of the 12 inch high footer is even with and/or below the main slab. This way you or the next person to own the house won't have the footer sticking up when trying to finish the basement floor.

Additional concrete and mortar can be added at a later date to cover the footing and level things out.
 

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The last tow posts are exactly how we do it here, but we also use adjustable columns, and it's important to support the "heft" of the column with concrete to take load off of the screw jack...........
 

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jo, we also use adjustables but i'd always thought the main reason for conc filling the steel columns was fire resistance as steel bends & collapses when exposed to hi heat,,, conc allows the steel to resist more the hot effects... isn't the main support still the screw on top of the column ? :huh:
 

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The Lally column was invented by John Lally, and has been manufactured by Dean Column since 1929. The original Lally column was a concrete filled tin plate tube, and has been improved and standardized since then. Dean Column currently uses 16 gauge steel tubing, and makes the column in either a 3-1/2 inch OD or 4" OD model. They use 3000 psi concrete to fill the tube.

The concrete provide most of the compressive strength of the column. For example, the 3-1/2 inch column has a net area of 9.6 square inches, of which about 9 square inches is concrete. At 3000 psi, the concrete would have a net compressive strength of about 27,000 lbs. The ultimate load capacity for a 6 foot long 3-1/2 inch diameter column is listed in the Dean website as 31,000 lbs, so you can see that most of the load is carried by the concrete.

As the column gets longer, buckling begins to control, and the allowable load decreases rapidly. For example, the same column in a 12 foot model has an ultimate load capacity of 16,400 lbs. Computing the buckling load on a composite steel/concrete structure is complicated, so it is fortunate that Dean has done the hard mathematics and published their table.

The concrete is claimed to provide greater resistance to fire than a hollow steel column of equivalent vertical load capacity, however there is no documentation offered in the Dean Column website. It is certainly true that steel weakens greatly when subject to heat, so the claim may well be true. In residential settings, a fire sufficiently hot to weaken steel in the basement would likely burn the house down completely, and there may be little advantage in having columns survive such an inferno. In industrial settings, there may be great advantage in having fire resistant construction, so there a concrete filled column may be important.

In any case, Dean Column makes their columns filled with concrete, and I believe they have very competitive pricing, since concrete is relatively inexpensive compared with steel, and their use of concrete allows them to use thin steel versus the required gage of their competitors.
 

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jo, we also use adjustables but i'd always thought the main reason for conc filling the steel columns was fire resistance as steel bends & collapses when exposed to hi heat,,, conc allows the steel to resist more the hot effects... isn't the main support still the screw on top of the column ? :huh:
I'm not talking about concrete "inside" of the steel column, but concrete around the bottom to lock the post in place both vertically & horizontally. The protocol here is to always place the screw at the bottom, encased in concrete. All adjustment should be made to the column before the floor is poured (or "diamonds" are left out around the columns, and patched in after the stucture is built) and if the columns would need to be adjusted later, the pad is probably failing anyways...........
 

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Discussion Starter #19
I realize this is an old thread I started, however when pouring the concrete do I want to add "bolts" or anchors for the lally column? Or will this be adjusted afterwords?
 

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I realize this is an old thread I started, however when pouring the concrete do I want to add "bolts" or anchors for the lally column? Or will this be adjusted afterwords?
What did your engineer call for? You can embed anchors or drill in expansion anchors afterwards.
 
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