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Frost Protection of Foundation/Footing

Inspector Gift said:
While I agree that our codes can use improvements, the word "FOOTER" is not used in any of the codes I have. Which code section is it used in your codes, Jeff? It always puzzles me when builders or inspectors use incorrect terminology, and yet claim they know the code. So, with all due respect, I humbly suggest that they clarify and check their own verbiage before criticizing the model code. Perhaps the word "FOOTER" is the same as "FOOTING" and still part of the foundation system?

Is not the "foundation wall" a system? Does it include reinforcement steel, anchor and holdown bolts, a minimum thickness, and a footing (or point of bearing)? Does a monolithic slab have a footing (or point of bearing)? -- I'd say 'YES" to all three questions!

The answers to my questions often become apparent when I strive to understand the INTENT and PURPOSE of a code section.
OK, you don't like the word footer, you would prefer footing. No problem, that is the way it is written. I will give you that because if I am being technical then I am wrong and should use the proper terminology. Thank you for bringing that to my attention.

That still does not, however take away from the fact that a footing is a footing and a foundation wall is a wall. Why then are footings under section 403 and foundation walls are under 404? They are integral to each other but still are clarified separately in the code and by construction.

A footing is the system in which the foundation sits on. It is the base. We rarely see monolithic pours and we do a footing inspection.

Afterwards, the foundation wall is constructed since the separate footing already was.

Together, however both the footing and the foundation wall are considered the foundation. A foundation includes both, but a foundation wall is only part of it, just like the separate footing is.

That is why the word "wall" is after the word foundation. It is a separate structure, most of the time constructed with a different material than the wall itself.

Therefore, it is our belief and has been since some of our municipalities had the BOCA standard that the foundation wall is a separately built structure and that structure must extend below the frost depth. There are footings, there are foundation walls and there is a foundation which is a combination of the two.
 
Keystone said:
Not to go off in another direction but "Inspector Gift" hit on one of my pet peeves, terminology - footer & masonary - footing & masonry
I have a similar one since 80% of the electricians and inspectors don't know how to spell "receptacle". Instead we get: recepticle most of the time and other variations such as resepticle, raceptacle, and so on.........

Kind of like when I point to a ceiling light box or smoke detector box and refer to it as an outlet. They look at me cross-eyed because they don't know the difference between an outlet and a receptacle.
 
Hmmm, are you measuring from the required minimum footing depth or from the as built footing depth? For speed and convenience I have simply poured the footing trench full to grade a time or two. On two that spring to mind, from there we built rubblestone walls, nothing was "slippery" to frost.
 
Therefore, it is our belief and has been since some of our municipalities had the BOCA standard that the foundation wall is a separately built structure and that structure must extend below the frost depth. There are footings, there are foundation walls and there is a foundation which is a combination of the two.
So why not take a position that in addition to foundation walls "other permanent supports of buildings and structures" such as beams, girders, and posts be located below the frost depth as well? That would be consistent with the position that the top of spread footings shall be located at or below the frost line to allow for the bottom of the concrete, CMU or PT wood foundation wall to extend below the frost depth.
 
There is no logical reason to extend the foundation wall below the frost line. Even if that is someones interpretation of the code it is ridiculous and probably(and rightfully) the quickest way to the unemployment line.
 
Agree with incognito on the first point but the reality is that wrong interpretations do not typically appear to have any consequences for the individual making them.
 
If the code stated clearly that the foundation had to extend below the frost line, I could understand. It does, however, clearly state that the "foundation wall" which is part of the foundation assembly must extend below the frost depth. It is physically impossible for the "foundation wall" to extend below the frost depth unless the entire footing is below frost depth. You see, that is how it is written. There is no gray area, the code specifies "foundation wall", not just foundation or footing. There is a reason behind it. I have contacted multiple inspectors about this privately and they all have the same opinion. I don't see how you can read those written words in the codebook and not come to the same conclusion.
 
jar546 said:
If the code stated clearly that the foundation had to extend below the frost line, I could understand. It does, however, clearly state that the "foundation wall" which is part of the foundation assembly must extend below the frost depth. It is physically impossible for the "foundation wall" to extend below the frost depth unless the entire footing is below frost depth. You see, that is how it is written. There is no gray area, the code specifies "foundation wall", not just foundation or footing. There is a reason behind it. I have contacted multiple inspectors about this privately and they all have the same opinion. I don't see how you can read those written words in the codebook and not come to the same conclusion.
So how do you reconcile the IBC's provision?

2009 IBC1809.5 Frost protection. Except where otherwise protected from frost, foundations and other permanent supports of buildings and structures shall be protected from frost by one or more of the following methods:
In an inverted T footing the foundation wall distributes its load through by spreading out into a strip footing. In essence the "foundation wall" does not mysteriously end at the top of the footing, but rather the wall continues through the expanded width of the footing. The issue is ground heave due to moisture laden soils freezing.
 
2006 IRC, Table R301.2(1), Frost line depth, Footnote b: The frost line depth may require deeper footings than indicated in Figure R403.1(1). The jurisdiction shall fill in the frost line depth column with the minimum depth of footing below finish grade.

A trench foundation has a built-in footing. Would you require a spread footing to bear lower than a trench? Isn't the 42-inch frost depth (here) the minimum bearing level of the entire foundation system?
 
Jar, you never responded to my post about diagrams R403.1(2) & R403.1(3) where the frost depth is shown at the bottom of the crushed stone layer, which is a minimum of six inches below the footer plate? This would seem to cement, if not set in stone, your argument, that the frost line be below the footing. ;)
 
Jar, you need to read and apply the entire section of that code provision. The charging statement is minimum depth for footings. The last sentence says the depths of footing where applicable, shall also conform to Sections R403.1.4.1 though R403.1.4.2. One of the methods is to place the footing below the frost depth, which the statement in R403.1.4 tells you you must do.The section you are hung up on says you need to protect foundation walls, piers and other permanent supports of buildings and structures from frost by one or more of the following methods. So in other words, if you place the footing below the frost depth, the code is saying that is one way to protect the foundation walls. You are reading way too much into the code.

R403.1.4 Minimum depth. All exterior footings shall be

placed at least 12 inches (305 mm) below the undisturbed

ground surface. Where applicable, the depth of footings shall

also conform to Sections R403.1.4.1 through R403.1.4.2.

R403.1.4.1 Frost protection. Except where otherwise

protected from frost, foundation walls, piers and other

permanent supports of buildings and structures shall be

protected from frost by one or more of the following methods:

1. Extended below the frost line specified in Table

R301.2.(1);

2. Constructing in accordance with Section R403.3;

3. Constructing in accordance with ASCE 32; or

4. Erected on solid rock.
 
That was my question too, but I didn't want to slow down the thread!

Joe
 
jar546 said:
Yes, but I have to throw myself into it.................Great responses from many, even though many of you are wrong
LOL

Now please answer papio's question about the figures that show a foundation wall sitting on crushed gravel where it clearly defines the bottom of the gravel as needing to be below the frost line, not the wall but the bottom of the gravel.

The diagrams are real cut and dry, the fon
 
Papio Bldg Dept said:
Jar, you never responded to my post about diagrams R403.1(2) & R403.1(3) where the frost depth is shown at the bottom of the crushed stone layer, which is a minimum of six inches below the footer plate? This would seem to cement, if not set in stone, your argument, that the frost line be below the footing. ;)
I am not familiar with wooden foundation walls without concrete footings. Looks like they made a mistake on the diagrams because it does not match the wording of the code. :)
 
jar546 said:
I am not familiar with wooden foundation walls without concrete footings. Looks like they made a mistake on the diagrams because it does not match the wording of the code. :)
I am feeling a bit under the weather today so that actually hurt when I bursted out laughing about who was making the mistake.
 
I hate to say it Jar, but you are wrong. The charging statement refers to footings placed below the frost line. Section R403.1.4.1 is a subsection of R403.1.4. Applying your logic the entire foundation wall would have to be below the frost line, which is virtually impossible.
 
"The charging statement refers to footings placed below the frost line. Section R403.1.4.1 is a subsection of R403.1.4."

As I said in post #37...........
 
Why can't the wall be part of the footing? Where is it in the code that the wall has to be poured in one continuous pour?

Figure R317.1(5) shows that the foundation wall is part of the footing.
 
gbhammer said:
I am feeling a bit under the weather today so that actually hurt when I bursted out laughing about who was making the mistake.
I think jar did an excellent job getting 4 pages out of this topic myself. Given that I worked on several projects with one of the ICC's consulting engineers for wood foundations, I feel fairly certain jar can only dig his footing hole deeper at this point if he still wants to come out on top.
 
for kicks and giggles, here is the 2006 IBC (Commentary in italics)

1805.2 Depth of footings. The minimum depth of footings below the undisturbed ground surface shall be 12 inches. Where applicable the depth of the footings shall also conform to Sections 1805.2.1 through 1805.2.3.

*Footings are required to extend below the ground surface a minimum of 12 inches. This is considered a minimum depth to protect the footing from movement of the soil caused by freezing and thawing in mild climate areas (see Section 1805.2.1 for general frost protection requirements).

1805.2.1 Frost Protection. Except where otherwise protected from frost, foundation walls, piers and other permanent supports of buildings and structures shall be protected by one or more of the following methods:

1. Extending below the frost line of the locality;

2. Constructing in accordance with ASCE 32; or

3. Erecting on solid rock.

Exceptions: Blah blah blah.

Footings shall not bear on frozen soil unless such frozen condition is of a permanent character.

*Unless the exception applies, the foundation is to be protected from frost in accordance with this Section. A common method of accomplishing this is by placing the footing bottom below the frost line.
 
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