Hollowcore Typical Large Opening Detail 1

[DayRooster]

Something that has bugged me regarding the typical hollowcore large opening detail is that shelf hangers/angles do not have any positive fasteners or tie-backs. The shelf angles support the cut planks and then just bear on adjacent hollowcore units with clip angles. Which just seems odd because just about every other type of opening in construction you see at least some means securing the support steel in place. Any thoughts from the community on this detail or am I just overthinking this one...

 

[dik]

I'll see if I can dig some up... some of the fasteners are used for securing steel studs to the HC and others are better for heavier loading... There used to be a problem (40 years back) with some of the fasteners causing a cone shaped fracture of the HC... but they've improved. I've even seen Korolath (sp?) used for bearing.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[DayRooster]

Bones - That report only applies to SDC C and above, correct? And optional SDC B <- whatever that means? I guess in those situations for SDC C and above, I would personally require a topping slab regardless of how many people complained

 

[DayRooster]

Dik - For sure, Korolath pads are common. But those aren't anchorage. Still very curious if you are designing the walls as free standing...mainly because that thought has crossed my mind a few times too.

 

[dik]

I didn't read through it, but the top of page 2 requires the HC slabs meet some dimensional requirements... just a quick first search... there's likely other products.

https://www.icc-es.org/wp-content/uploads/report-directory/ESR-2269.pdf

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[dik]

Korolath... I guess I spelled it correctly... it's a bearing material only... not anchorage. I've never secured the HC slabs... I've always assumed the bearing weight and the keyway grout held them in place... I've not used them in seismic locations...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[DayRooster]

Dik - Just a heads up but if I understand your detail properly then the PCI manual states that the wall is not braced at top by the hollowcore...which is all good as long as that’s accounted for in the wall design.

As for the anchors, I have seen those one from Hilti. Again I don’t use them because they are too restrictive. I will allow a substitution if hollowcore vendor can show they comply (which only a few can) but it’s not first design on my drawings. Also from what I’ve seen all the anchor vendors have the same restrictive criteria (Hilti, Simpson, powers, dewalt, etc)

 

[dik]

I suspect there are thousands of sq ft of HC slab providing lateral support for steel stud partitions in north america... whether the PCI states the wall is braced or not... unless I'm misunderstanding something... I've not used them recently, but early projects, steel stud top rails were secured to the HC slabs... it was common.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[DayRooster]

Dik - I think I am a bit lost with your description. I was trying to follow but now I am confused with your last statement. I assume you understand structural bracing requirements and I'll let you be the judge of that since I assume you are the EOR on those projects.

 

[jayrod12]

Before this gets too far, I believe you two are talking about two different types of wall bracing.

Dik is talking about the hollow-core bracing non-load bearing steel studs. At least that's what I think he's getting at, even load bearing steel studs likely.

DayRooster I believe you're more talking about connections to hot rolled framing, or concrete walls(I assume with weld plates that's more for connections to precast walls). We have anchor bars into the wall and grout joints and consider the walls braced where I am. Considering the bulk of the walls around here are foundation walls resisting soil pressure, the load is transferred directly through the bearing ledge and upstand to the hollow-core and therefore would be considered braced as well.

 

[DayRooster]

All good jayrod. I see now Dik is talking about interior walls towards the end. I was thrown off by his quote, "I've never secured the HC slabs... I've always assumed the bearing weight and the keyway grout held them in place...". I thought he was talking about not securing the HC slab. Honestly I was just curious how he was swinging it to make it work for wall bracing on the exterior. Like I mentioned, I have considered free standing exterior walls before...but then it all got confusing so I let my curiosity go so I did not come off negatively.