3000 psi Concrete Requirement 2

[msquared48]

I have a small residential metal building foundation (30 X 42) on uneven topo with some exterior foundation walls having up to four feet of concrete exposed to the weather. The owner received a comment back from the local jurisdiction (King County) that 3000 psi concrete is required in this area of exposed concrete. This will throw the concrete into the inspected range since it is over 2500 psi. The requirement seems ridiculous to me.

Does anyone know of a specific code reference in the IBC requiring this 3000 figure in this circumstance? If not, then I may be dealing with a local upgrade, or an over exuberant plans examiner trying to be an engineer.

Yea... like that never happens.

Mike McCann
MMC Engineering

 

[sandman21]

I don’t have my code but special inspection is still required for 2500 psi concrete, however if you spec. 3500psi and design for 2500 psi, you can waive the batch plant inspection. Section 1704 something.

 

[RHTPE]

Sandman21 may be correct - See 1704.4, paragraph 2.3, which is part of a list of exceptions.

BUT, as I read that section more carefully, I suspect the exceptions apply only to footings.


Ralph
Structures Consulting
Northeast USA

 

[RacingAZ]

The way around this is you design for 2500 psi (show it on your calcs) but spec out 3000 psi on your plans. Works for me all the time with regards to the plan checker. You won't need a concrete inspection (for 2500 psi or lower per IBC) but you'll get a higher psi concrete. This is the solution if you're just trying to avoid an inspection and satisfy the plan checker.

 

[sandman21]

Section 1704.4.2 exception says it applies to continuous footings under light-frame construction and to concrete foundation walls designed per Table 1805.5(5). As long as you meet the table and the concrete was designed for 2500 psi special inspection is not required, but spec. the 3000 psi so the plan checker is happy.

The section I mentioned in my pervious post is a DSA requirement which does not apply.

 

[dik]

JAE:
Also, according to the IBC, a building official has the right to increase the minimum requirements of the IBC (they can't diminish them).


Can the building official do this, or is it a matter of a local building by-law? Seems like they are being given more clout than they deserve...

Dik

 

[JAE]

My son (an architect) has been recently complaining about their local building officials "practicing architecture" in their plan reviews, requiring all sorts of wild things (one example was in a high school classroom where they required two separate sinks in the chemistry lab vs. the single one they had designed. The official said something to the effect that they thought it made better sense, allowed for chemicals in one sink and non-chemicals in the other, etc...even though both sink drains immediately went to the same outflow pipe.

He believes they are way overstepping their bounds but what do you do about it when they have the power to grant building permits?


I thought Chapter 1 of the IBC gave direct power to the building official to increase the minimum standards of the code but I couldn't find it directly.

My son and his firm are thinking about complaining to a higher authority in their city (not prayers) but that has its pitfalls too.

 

[sandman21]

Your son should be thankful his in not an architect in CA, he would hate DSA, think of the worst building official you have ever had and take it up a 100 notch’s. lol Also lots of people think the BO is stepping over the line when really they are not.