Concealed Flange Hangers 1

[XR250]

How do y'all feel about these types of connections at the end of the beam? The capacity does not seem to be reduced in the Simpson tables. Seems like fastener end distance would be an issue.

 

[ANE91]

My understanding is that Simpson publishes strength values for the connector, only. Wood failure modes are not considered. I recall exchanging phone calls and emails with them about cross-grain bending, so I may be extrapolating about all failure modes, but I specifically understood that they precluded failure from tension perpendicular to the grain in their testing. That failure is obviously not applicable in your scenario, but it begs your question about potential end/edge failures.

That said, I’ve spec’d these when I had to, like for a contractor oopsie when reframing was not on the table.

 

[XR250]

I might spec a THAC hanger so I can fold it over the top of the beam (11 7/8" LVL's).

 

[dtimberlake]

Yeah, fasteners splitting the end of the beam, espcially if the grain was like this.

https://images.thdstatic.com/productImages/880cca39-c8df-4f12-a0aa-b48636f46c42/svn/framing-lumber-108524-64_600.jpg

• Single Joist — Fill all round holes on one leg of HUC with #10 screws to web of joist.
• Boxed Joist — Fill all round holes on both legs of HUC with #10 screws to web of both joists.

I get scared pumping #6 drywall screws close to the end of studs.
Pre-drilling 1/8" holes would definitely be on my mind.

 

[jerseyshore]

Did you check to see if the end distance values reduce the loading for that hanger? We've used these a lot, usually with light loads.

 

[jhnblgr]

ICCES_ESR2551.pdf

ssttoolbox.widen.net

 

[XR250]

I looked at the ESR for HUC hangers. They do not mention anything special about their use. I can't imagine there would be no reduction in capacity. Way too easy to split the wood with fasteners that close to the edge. I wonder if they are actually tested or are they just saying "well, it oughtta work the same"

 

[Eng16080]

I would hope the connection with the configuration shown would generally work, at least for them to show it in a picture like that in their catalog.

While there is a point where the capacity of a nail will be diminished when placed too close to the end of a beam, the NDS code interestingly doesn't enforce spacings and edge distance for nails, it only gives recommendations in the code commentary.

For me, I would typically only use a connection like this as a last resort. Even then, I might try to use a top flange hanger instead (if they make such a thing which doesn't project beyond the end of beam). The THAC422 noted above is probably a better solution.

 

[XR250]

Hence why I am going to use a THAC truss hanger so I can fold the straps up and over the carrying member.
My demand is 1,600 lbs so more than I feel comfortable with with sketchy nails, 1/4" from the end of a member.

 

[ANE91]

ICCES_ESR2551.pdf

ssttoolbox.widen.net

Footnote 3 of Table 2 supports my understanding. The engineer needs to check the wood. Simpson doesn’t.

While there is a point where the capacity of a nail will be diminished when placed too close to the end of a beam, the NDS code interestingly doesn't enforce spacings and edge distance for nails, it only gives recommendations in the code commentary.

Generally agree, but see below. Looks like enforcement to me. The tables provide the numbers (e.g., 12.5.1C).

 

[RWW0002]

Simpson has been very responsive in the past to my questions (aim them at a "field engineer" for your area). I have been impressed at how much they internally test connectors and fasteners in various applications and they are generally willing to share data with you, even for non-standard installations.

The published data will be based on the ESR which will itself be base on certain acceptance criteria (AC) approved by ICC. They may well have additional data beyond that published in the ESR or their catalogues that they are willing to share.

I recommend reaching out.

 

[Eng16080]

Generally agree, but see below. Looks like enforcement to me. The tables provide the numbers (e.g., 12.5.1C).

Those tables aren't applicable to nails and wood screws (assuming diameter < 1/4").

Section 12.1.6.5: Edge distances, end distances, and fastener spacings shall be sufficient to prevent splitting of the wood.

True, the code does state that, but then fails to provide any distances for these things. Kind of like saying: "Beam to safely resist all required loads." The code commentary does however provide some good guidance. For this particular case (per OPs question), though, I don't think the commentary addresses end distance with loading perp to grain.

 

[Eng16080]

Simpson has been very responsive in the past to my questions (aim them at a "field engineer" for your area). I have been impressed at how much they internally test connectors and fasteners in various applications and they are generally willing to share data with you, even for non-standard installations.

Agreed. I'm generally hesitant using 3rd party products, but Simpson is definitely one of the better (more trustworthy) companies in my opinion.

I still haven't received a single free vacation though, like every builder is suggesting I get in kickbacks for spec'ing their products.

 

[XR250]

I reached out to the Simpson rep. I'll let you know what they say.
Seems like there is too much possibility for issues with concealed flange hangers. What if the carrying beam is cut 1/8" short and then the edge distance is like 1/8" No one notices it split or it does not until load is applied.
I think I will stick to using these for light loads (under 500 lbs) or welding to beams for saddles.

 

[XR250]

Simpson is definitely one of the better (more trustworthy) companies in my opinion.

They are but there is still a lot of fine print in their catalog that gets unnoticed and IMHO is intentional so they can sell more product.

 

[ANE91]

Those tables aren't applicable to nails and wood screws (assuming diameter < 1/4").

Good call about the quarter-inch threshold. Most nails and screws don’t get that big. Anything larger and the geometry factor kicks in hard, per 12.5.1.2.

 

[RWW0002]

They are but there is still a lot of fine print in their catalog that gets unnoticed and IMHO is intentional so they can sell more product.

I agree that there is some marketing to the fine print, and I am sure there is likely some push-back between the "sales" guys and the "engineering and/or testing" side as to what goes into manuals. I think some of the fine print has to do with the ICC system I alluded to above (testing to an established AC protocol and then having to state to caveats) There is also likely some level of competition between suppliers/products. ex. company A publishes certain data based on very specific conditions. This forces Company B to either match those conditions and note it in a million footnotes or appear to have a sub-standard product via lower allowable values.

 

[fp23]

For light loads (under 1k) it doesn't bother me too much. I've used it in this orientation a lot and haven't ever noticed splitting but I can't say I've been looking out for it. A simpson rep told me once that they use a factor of safety of 4 on their hangers and I usually scale down my hanger capacities by .7 to account for framers using gun nails. With all of those factors of safety it feels pretty safe to me.

If the loads are high, you could use an LVL which is probably less likely to split, or if it's to a ledger just stop the ledger short and hang directly to framing in the wall behind it.

 

[XR250]

Photos of testing from Simpson Rep....

 

[RontheRedneck]

I looked up the text on Simpson's website about how they rate hanger capacities:

"Evaluation is based on a minimum of three static load tests in wood assemblies. The published allowable load is the lower of the tested ultimate with a safety factor of 3, load at 1⁄8" deflection or the NDS fastener calculation limits. "

Seems to me that's some pretty conservative values. And in the past 40 years I've had zero issues with hangers.

In this case I'd be inclined to let it go. Unless the hanger was at something like 90% or more of capacity. Then I'd think about alternatives.