UL263 - Loading of Test Specimens

[blugosi]

Still trying to figure out how TVs or furniture hanging on fire partitions affect their fire listing :-(

Looking at UL263 reference in the UL site, the article "Loading of Test Specimens" refers:

UL 263 requires the load applied to test samples to be based upon the limiting conditions of design as determined by nationally recognized structural design criteria.

If I am reading this correctly, the UL263 tests of a 1 hr wall assembly have been carried out with the vertical loads allowed to that assembly in normal (non-fire) conditions.
Am I right or am I missing something?
If the answer is yes, this may be the best justification for my projects.

 

[princeofpen]

How could anything hanging on a tested assembly NOT effect it would be my question in response. Structural load, heat transference of fasteners, or changes to heat transfer from the room to the wall with a TV etc in the way of the radiation.

 

[steveray]

As the IBC requires design of 5 PSF min I would assume that they are all at least tested to that or maybe we need to fire all of the testing labs....

1607.16 Interior Walls and Partitions​

Diagram
Interior walls and partitions that exceed 6 feet (1829 mm) in height, including their finish materials, shall have adequate strength and stiffness to resist the loads to which they are subjected but not less than a horizontal load of 5 psf (0.240 kN/m2).

 

[blugosi]

As the IBC requires design of 5 PSF min I would assume that they are all at least tested to that or maybe we need to fire all of the testing labs....

1607.16 Interior Walls and Partitions​

Diagram
Interior walls and partitions that exceed 6 feet (1829 mm) in height, including their finish materials, shall have adequate strength and stiffness to resist the loads to which they are subjected but not less than a horizontal load of 5 psf (0.240 kN/m2).

This is Code requirement, I am not sure how safe it is to assume that the UL263 test is actually applying a horizontal force of 5 psf.
Never witnessed such a test myself.

However, I understand that this IBC article refers to horizontal , not vertical loads. Not exactly what I am looking for.

 

[Yankee Chronicler]

This is Code requirement, I am not sure how safe it is to assume that the UL263 test is actually applying a horizontal force of 5 psf.
Never witnessed such a test myself.

However, I understand that this IBC article refers to horizontal , not vertical loads. Not exactly what I am looking for.

The load imposed by something like a flat screen television hung off a wall is an eccentric load. In other words, the center of mass of the television isn't located directly above the centerline of the studs. This means that, although gravity acts vertically in the television, the load isn't transferred vertically to the wall. Of course, it isn't transferred horizontally, either. In fact, it's a rotational force.



The screws want to pull out of the wall, imparting a torsional load on the studs. But it's a relatively small, concentrated load. How much does a typical flat screen television weigh? 50 pounds? 100 pounds? If we assume a wall 8 feet high with studs at 16 inches on center, each stud has a tributory area of 8' x 1.33' = 10.64 square feet.

10.64 s.f. x 5 psf = 53.2 pounds. And wall studs are repetitive elements, so we can assume that some load is shared with the studs on each side. In fact, for something like a flat screen television. there's probably blocking in the wall to distribute the load over at least three studs.

I don't see a problem.

 

[blugosi]

The load imposed by something like a flat screen television hung off a wall is an eccentric load. In other words, the center of mass of the television isn't located directly above the centerline of the studs. This means that, although gravity acts vertically in the television, the load isn't transferred vertically to the wall. Of course, it isn't transferred horizontally, either. In fact, it's a rotational force.

The screws want to pull out of the wall, imparting a torsional load on the studs. But it's a relatively small, concentrated load. How much does a typical flat screen television weigh? 50 pounds? 100 pounds? If we assume a wall 8 feet high with studs at 16 inches on center, each stud has a tributory area of 8' x 1.33' = 10.64 square feet.

10.64 s.f. x 5 psf = 53.2 pounds. And wall studs are repetitive elements, so we can assume that some load is shared with the studs on each side. In fact, for something like a flat screen television. there's probably blocking in the wall to distribute the load over at least three studs.

I don't see a problem.

The attached image is a sample page from one major European manufacturer's installation booklet, where they provide simple tables with the cantilever loads permissible for each system, using approved screws and fasteners/

Similar documents are available by all manufacturers.

The thing is that local distributors hesitate to give a clear answer on whether hanging such loads on a rated partition voids the fire rating certification.

Since my current projects are US based hotel companies and American Codes are applicable, i am investigating the exact US Code or Standard reference stating that a UL263 certified system maintains its fire rating if we hang cantilever loads within the structural limits.

Which exactly are the "limiting conditions of design as determined by nationally recognized structural design criteria" mentioned in the UL263 test?

Per IBC definitions, any metal or wood stud wall that supports up to 100 pounds per linear foot (1459 N/m) of vertical load in addition to its own weight is a non-bearing wall.

Is this within the "limiting conditions " mentioned in UL263?

 

[redeyedfly]

The attached image is a sample page from one major European manufacturer's installation booklet, where they provide simple tables with the cantilever loads permissible for each system, using approved screws and fasteners/

Similar documents are available by all manufacturers.

The thing is that local distributors hesitate to give a clear answer on whether hanging such loads on a rated partition voids the fire rating certification.

Since my current projects are US based hotel companies and American Codes are applicable, i am investigating the exact US Code or Standard reference stating that a UL263 certified system maintains its fire rating if we hang cantilever loads within the structural limits.

Which exactly are the "limiting conditions of design as determined by nationally recognized structural design criteria" mentioned in the UL263 test?

Per IBC definitions, any metal or wood stud wall that supports up to 100 pounds per linear foot (1459 N/m) of vertical load in addition to its own weight is a non-bearing wall.

Is this within the "limiting conditions " mentioned in UL263?

UL263 requires the test specimen to be loaded to it's max allowed by the building code. If it is loaded less than that it will be noted in the listing with a % of maximum load restriction. When the walls are designed by an engineer, they will be loaded less than what was used in the test (assuming the wall is listed as load bearing). If there is a restriction, the engineers must design it to less than the listing, e.g. 80% restriction, they would need to design a wall in which the design load does not exceed 80% of the capacity. TVs and other similar items attached to the wall are negligible.

100plf in the definition of a load bearing wall in the IBC has no relation to the UL263 test loading.

 

[blugosi]

UL263 requires the test specimen to be loaded to it's max allowed by the building code. (...) TVs and other similar items attached to the wall are negligible.

100plf in the definition of a load bearing wall in the IBC has no relation to the UL263 test loading.

Yes, this is what I understand as well, but are you sure the loading referenced by UL is a vertical load, and not horizontal?

And what is the maximum load allowed by the Code for a non-bearing partition or wall if not the 100 plf?

And as far as load bearing wall definitions are concerned, what are the UL263 definitions of load bearing vs non load bearing? Ul263 fire rating certificates are very clear on what they have tested.

Sorry for the multiple questions :-(

See two examples:

 

[redeyedfly]

If it says "Bearing Wall" on the listing, the engineers can design it to its full design capacity. By bearing they mean structural loads, not TVs.

Again, the 100plf in NOTHING to do with the UL263 test. 100plf is definitely NOT a maximum. The maximum amount allowed by code is determined by the required calculations in the code which are done by your engineers.

You're overthinking this. No plan reviewer or inspector in my 30 years of doing this has ever mentioned the load of a TV or casework on a bearing wall, rated or not.

 

[blugosi]

If it says "Bearing Wall" on the listing, the engineers can design it to its full design capacity. By bearing they mean structural loads, not TVs.

Again, the 100plf in NOTHING to do with the UL263 test. 100plf is definitely NOT a maximum. The maximum amount allowed by code is determined by the required calculations in the code which are done by your engineers.

You're overthinking this. No plan reviewer or inspector in my 30 years of doing this has ever mentioned the load of a TV or casework on a bearing wall, rated or not.

I tend to agree.

The issue is that in most European projects, the local AHJ expects a signed statement by the contractor that the fire rated partitions/barriers made of steel studs and gypsum boards have been installed per the manufacturer's listing conditions, and the manufacturer's local representative (usually Knauf, Saint Gobain or Promat in my region EMEA) to sign a similar attestation.

Some manufacturers have sent emails distancing themselves, stating that their systems were not tested with vertical loads.

And we are stuck!

I am trying to find a path of arguments, based on the fact that all of these manufacturer's have certified their systems with UL through their US based affiliates, and if I prove to them that the UL 263 listing is not voided if we hang flat screen TVs or clothes hangers on both sides of a wall separating two hotel rooms, they will have to withdraw their concerns.

BTW, thank you all for your valuable help!!!!