Can someone point me in the direction of the IRC maximum amount or have a knowledge of how many stacked wood 2x blocks are allowed on concrete block piers to support the main girder system?
For our understanding from framing contractors, a maximum of three 2x blocks are allowed, then metal shims installed after for final leveling.
If we are wrong, we want to know what is right.
Thanks in advanced!
4", or more, concrete (don’t know about steel shims) is required, I believe. I believe that is because one can buy a solid 4" block ready to go, but not for sure on the reasoning.
And, I believe 5 or more blocks, in one pier, need to be core grouted.
Sorry, don’t have the code.
Edit: Try CODES.docx (10.6 KB)
or this:
Codes by state.docx (7.8 KB)
2018 IRC for the use of CMU’s in piers R606.7.
The “Codes” do not address the use of wood as shims for the very reason you are stating that it can be compressed and cause movements.
Although not “best practice”, those wood 2x’s are never going to compress, so I wouldn’t worry about it.
I agree with Stephen. You might be going a bit overboard. Home inspectors do not do code inspections and you would have to admit nobody is going to do anything about the issue anyway.
Cheers
I believe there is no fine line between inspecting for defects and performing engineering and whatever this is it ain’t home inspecting as per any SOP.
This is one of those that falls under the what’s acceptable locally. While HUD has some hard rules that limit the total height of the wood blocking and shimming (varies with the area), IRC does not. If you did not notice any depressions from the beam in the 2x blocking, the only way to verify if it’s adequate is to do some math. This falls under engineering. If plans are not available to show this is acceptable, the only way to get this off your back, if you don’t feel comfortable taking on the liability, is to call it out for review by a SE. Remember, unsupported masonry piers are limited in height by IRC. One cannot just stack unlimited number of 2x to support a beam. Ideally, the masonry pier would go up all the way to the bottom of the beam and up to 1inch is filled with a metal shim. But… we don’t live in ideal world, so… The issue here is that someone can come behind you and throw you under the bus, even if nothing happens as a direct result of these four 2x.
If that is new construction and you are concerned, call your AHJ for a clarification on what he/she will accept. If it is a 2+ year old house, then those blocks are performing. Around here, our AHJs would accept that.
What do you guys think of this one from yesterday’s new construction inspection? Looks like more wood used than concrete. BTW, I’m in the same state as the OP.
Look close at the second picture. To make room for that 5th piece of 2x8 shim they actually notched out the bottom of the beam.
I’d could be happy with it, depending on what I saw on close inspection. The issue of concern is the beam twisting over time. Loading plus drying of the beam (and the possibility of twisting) needs to be addressed. Twisting is of particular importance with southern yellow pine, which that beam may utilize. That issue may or may not have been addressed by what is visible in your photo.
I’m not seeing the whole picture, but why is that beam there? Appears to be a pretty short span then a beam in between.
It’s what I thought, too…especially for new construction. 
Library, Fish tank, Baby Grand, Hydro-massage ‘Party’ tub, etc…
Here are a few pictures from February when I did the pre-drywall inspection.
The beams are under the stairs.
Remember that picture of the wet corner in the crawlspace? Well here it is this week:
This one got away from the builder. His head should be spinning. And of course, no vapor barrier. I doubt the AHJ would go for that.
This is odd as well. No beam here?
What a mess Burt, including your video with all the water. What did the rest of the structure look like above the crawl space?
I see now he added the vapor barrier/pool liner. 
It looked pretty good. It new construction so we might not see the settlement leading to wall cracks and wonky door and window frames for a little while.
OMG, there is a dog in the crawlspace! Is there a dog den? Of all the animals that I’ve seen in crawlspaces, so far, no dogs.
