I am a home owner building my own home. My city is using 2009 IRC as the basis for their code enforcement. I need clarification about pouring my footers, my local building inspector says I must dig a trench and pour my footers in the ground and can not build forms to encase the footers. I have dug the crawl space down 2’ below existing grade and would like to form up my footers on top of this undisturbed soil, lay my block foundation to 4’ then backfill on the outside against the block to about 3’ all the way around the house. I purchased a used volume of the 2009 IRC to reference while doing the build and Section R408.6 appears to allow for the footers to be poured on top of the finished grade under the house. Can you advise?
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Pouring footers in forms.
- Thread starter Carlos711
- Start date
Mr. Inspector
SAWHORSE
Where I am we require forms for footers.
my250r11
Sawhorse
It should not be a problem as long as your below frost depth and remove the form after pouring.
fatboy
Administrator
Ditto to my250r11's reply!
Beniah Naylor
SAWHORSE
Why is that?
Could be a function of soil type … stability … ability to maintain the wall of the trench.
Mr. Inspector
SAWHORSE
We go down 42" here. Without forms dirt, rocks and even people easily can fall down the slope into the concrete when being poured, never to be seen again.
"Rough neighborhood!", better call Saul!
The inspector is wrong. As long as the as poured concrete is equal to or more than the dimensions in the footing detail there is no problem.
Concerns about the need to remove form material does not give inspector the right to prohibit the forming of the footing. What is the Code provisions that justifies the inspectors actions?
How do you reconcile the inspectors demand that no forms be used when the code has provisions for permanent wood footings constructed using treated wood.
Concerns about thing falling into the concrete are not a reason for prohibiting the use of forms. In fact the use of forms will tend to prevent dirt and debris from falling into the concrete.
The inspector needs to enforce the code not his concerns.
Concerns about the need to remove form material does not give inspector the right to prohibit the forming of the footing. What is the Code provisions that justifies the inspectors actions?
How do you reconcile the inspectors demand that no forms be used when the code has provisions for permanent wood footings constructed using treated wood.
Concerns about thing falling into the concrete are not a reason for prohibiting the use of forms. In fact the use of forms will tend to prevent dirt and debris from falling into the concrete.
The inspector needs to enforce the code not his concerns.
Beniah Naylor
SAWHORSE
Mark, that was Rick's point.
mtlogcabin
SAWHORSE
This is the only part in the IRC that would require you to have lateral support at the bottom. Since your walls will not be supporting more than 48 inches of unbalanced backfill then item 2 of this code section is not applicable to your project as described.
Are your walls subject to hydrostatic pressure from ground water? If they are then provide bottom lateral support or get an engineer.
Around here the contractors always form on top of the undisturbed dirt and if the unbalanced backfill is more than 48 inches then they will provide lateral support at the bottom.
2012
R404.1.3 Design required.
Concrete or masonry foundation walls shall be designed in accordance with accepted engineering practice when either of the following conditions exists:
1. Walls are subject to hydrostatic pressure from groundwater.
2. Walls supporting more than 48 inches (1219 mm) of unbalanced backfill that do not have permanent lateral support at the top or bottom.
Are your walls subject to hydrostatic pressure from ground water? If they are then provide bottom lateral support or get an engineer.
Around here the contractors always form on top of the undisturbed dirt and if the unbalanced backfill is more than 48 inches then they will provide lateral support at the bottom.
2012
R404.1.3 Design required.
Concrete or masonry foundation walls shall be designed in accordance with accepted engineering practice when either of the following conditions exists:
1. Walls are subject to hydrostatic pressure from groundwater.
2. Walls supporting more than 48 inches (1219 mm) of unbalanced backfill that do not have permanent lateral support at the top or bottom.
mtlogcabin
SAWHORSE
Agree
I was just pointing to a code section the inspector may quote to the builder that would not be relevant for his project and location in requiring the footings be in a trench
I was just pointing to a code section the inspector may quote to the builder that would not be relevant for his project and location in requiring the footings be in a trench
Thank you. This exactly what I thought.
Mr. Inspector
SAWHORSE
IRC 403.1.1"Footing projections shall not exceed the thickness of the footing". This is hard to control in a rough dug out ditch without forms.
Apply common sense to this please.
The intent of this section ties back into plain concrete footings, and having a footing that is wider than it is thick for the portion extending beyond the face of the foundation wall. Load disperses at an assumed 45-deg. angle through the concrete. Therefore, when sizing a footing, to prevent the foundation wall from punching through the footing, the depth of the footing needs to be increased to match the projection of the footing beyond the wall.
Now, as long as the footing is wide enough and thick enough for the applied loads, why would it matter if the footing was poured a bit wider than required? Do you want them to come back and saw cut a portion of the footing off? Intent of the code is to prevent punch-through of the wall through the footing in plain concrete.
Mr. Inspector
SAWHORSE
So you are saying we do not need to comply with IRC 403.1.1? Why is it there then?
I am not saying that we do not need to comply. What I am saying is that over-pour is ok. As long as the design is appropriate, a couple extra inches is not a problem.
Mr. Inspector
SAWHORSE
If a couple of inches is OK why isn't the section changed to say that?
Because the code is a minimum standard. And in this case, it is all based upon plain concrete footings.
Genduct
Registered User
If I understand what you are proposing, your are excavating the crawl space to the bottom of the footing and forming up the sides, then building the stem walls and then backfilling the outside dirt ( probably before your add the weight of the structure above or any dirt to the inside of crawl space.
If so, your inspector, like me is concerned about the lack of Lateral Support that the inside dirt would give the footing and wall to avoid having the outside dirt push sideways toward the interior of the crawl space
Msradell
Sawhorse
I'm guessing that that's the case and the same situation would apply if the footing is poured in the ground. Many places require the 1st floor decking to be added before you backfill. That should solve the problem in either case.
I personally prefer when they are poured into forms instead of against excavated earth.