Another how to fix it thread

[TRAK.Structural]

So a contractor I do work with from time to time called me out to look at something. The inspector failed his floor framing because he over-notched the joists due to an existing 2x4 ledger strip (dark colored wood) rather than the typical 2x2 strip (it's a renovation job). So now I'm trying to rationalize if/how I can make this work. My first thought is to just have them put hangers on each joist and nail them to the 2x4 ledger strip, but this 2x4 is only face mounted to the rim/band behind it with no vertical support from below. Ideally I want most of the load being transferred directly to the band which is vertically supported by the foundation wall instead of to the 2x4 and then to the band through nail shear. Am I over thinking this? What does the group think?

 

[Flotsam7018]

If you can get an LUS24 or similar to work and add fasteners from the ledger strip back to the rim, I don't see a problem with that.

Otherwise, you could toy with checking the notched shear capacity per NDS and add some reinforcement screws through the depth to prohibit a split propagating from the notch.

 

[BN4537]

Assuming one or two family residential. Hoping a commercial guy didn't do that...

From the 2021 IRC Table R602.3(1).



Then size the joist hangers/angle brackets per span.

 

[SE2607]

I would add an LUS face mount joist hanger and an LTP4 over the area where the member is/likely to split.

 

[SWComposites]

Nice that they added a split starter notch also.
"eh, the toe nail will hold it"
can you lag bolt the ledger to the rim?

 

[ANE91]

Agree with @Flotsam7018. Lag screw edgewise through the depth to restrain tension perpendicular to grain.

 

[XR250]

I would fasten the top blocking and the bottom ledger to the band with some structural screws and add a full-depth hanger.
What is the demand?

 

[KootK]

If all load paths to the foundation wall must pass through the connection between the ledger and the rim, then I like hangers. Ideally face mount hangers that can get the job done over the height of the 2x4 ledger if possible. Do whatever you must to connect the ledger and rim appropriately.

A bunch of overhead installs of GRK screws in a 2X for notch reinforcement (lags too large) is a pretty big ask in my opinion. And I don't see what advantage that would have over hangers if hangers would work.

 

[Greenalleycat]

I agree with Koot

Also, laughing at the nice nailing from the floor that completely missed the joist at the top of the photo

 

[Tomfh]

I’d use hangers too, ones with nail holes full depth of the hanger, not just at the top. That way you stitch across the notch.

Hammer in packers between the dark wood and the light wood., that way you can mobilise both.

 

[ANE91]

At least the glue is there

 

[TRAK.Structural]

Nice that they added a split starter notch also.

Yea the split starter notch is great, compliments to the chef.

I would fasten the top blocking and the bottom ledger to the band with some structural screws and add a full-depth hanger.
What is the demand?

Demand is 440# (D+LL). SDWS screws at 200#/screw should be pretty easy to carry that load back to the band, and good idea about a full depth hanger.

 

[Ron247]

Greenalleycat, it is a common misconception among engineers how construction workers view proper equipment usage. They most likely used an air gun. Air guns are meant to nail air. You must be thinking of a wood gun. They did properly nail the air, but usually I space air nails a little closer since the have limited grip unless the humidity is high.

 

[Enable]

Of those commenting on the nails missing the joist, how do you know they didn't realize when they felt the nail discharge and try again? Perhaps that is why there are two already so closely spaced in a sub-floor. They clearly tried somewhat as evidenced by the adhesive, which would be entirely missing if they were not attempting to do an adequate job. Moreover, have any of you attempted to build a home or even just a subfloor, not for yourself, but under a constrained budget and time scale that really only permits one to move forward? They are shooting nails blind into the floor. Give them a break for peats sake.

 

[Ron247]

Enable, not speaking for others, but only myself, just having a little fun.

 

[Greenalleycat]

Greenalleycat, it is a common misconception among engineers how construction workers view proper equipment usage. They most likely used an air gun. Air guns are meant to nail air. You must be thinking of a wood gun. They did properly nail the air, but usually I space air nails a little closer since the have limited grip unless the humidity is high.

You learn something new every day - this is why I visit this forum
Going to start speccing structural air screws in my future designs

 

[Ron247]

Now I have a real problem. I am constantly picturing a free-body diagram of a nail into air. I have 14.7 psi air pressure applied to the exposed surface of a 16d nail. If we can find a reference with the coefficient of friction between steel and air, we might be onto something. Its like a song you can't get out of your head. Until we can solve this, I am not tackling the structural air screw, much more difficult.

Gosh, I need a nap.

 

[Greenalleycat]

Now I have a real problem. I am constantly picturing a free-body diagram of a nail into air. I have 14.7 psi air pressure applied to the exposed surface of a 16d nail. If we can find a reference with the coefficient of friction between steel and air, we might be onto something. Its like a song you can't get out of your head. Until we can solve this, I am not tackling the structural air screw, much more difficult.

Gosh, I need a nap.

All we have to do is get them to build a fully air sealed subfloor
Then we can assume that the air will behave like an incompressible fluid as it cannot escape and thus our shear capacity will go through the roof....

 

[Stick.]

I am not tackling the structural air screw, much more difficult.

I think it should be easier since you don't need to rely on that fickle thing called friction. Just need the tensile strength of air and you can plug it into your standard thread strength equations. Should be pretty easy to get air's tensile strength too, just make sure the tension tester isn't running in a vacuum and then run a few tests.

 

[ANE91]

This thread is going to completely screw with any AI being trained on this site.