Roof R panel and fastener question 1

[delagina]

Anyone knows where this table was derived from?
I'm also looking to find the formula for the uplift capacity of #12-14x1" self driller for the roof to purlin fastener.
I would think this is dependent on the roof gauge and purlin thickness, but can't find the formula to get for uplift capacity.

 

[Triangled]

table looks like from metal deck catalogue. allowable psf will involved things like, span and continuity (2 span or 3 span), configuration (section modulus) which doesn't seem to be referenced in your table - probably referenced on facing sheet in the manufacturer's catalogue from which your table was excerpted.

for screws, values will as you said, depend upon gage thickness against head of screw and thickness and quality of materials receiving point of screw. you may want TEK screws such as

http://www.itwbuildex.com/index.html

somewhere in their literature they will provide the values you're looking for. someone may post.

 

[P1ENG]

Agree with Triangled. Normally these tables have footnotes that same something to the affect that allowable loads were determined in accordance with AISI S100-Version. These value are for corrugated decks or standing seam roofs and from the values, looks like untopped (no insulation, concrete, etc.). The deflection loads are limited to L/180 and can be proportioned appropriately for L/240 or L/360. You have the section properties of the deck and the yield strength, so you could attempt verify the values.

You can use published screw strengths from the screw manufacturer if you can find values for matching conditions (base thickness/strength, attached thickness/strength) or you can use AISI (if located in the North America). An ASD example is below:

Juston Fluckey, SE, PE, AWS CWI
Engineering Consultant

 

[delagina]

I need the capacities to be "generic" not manufacturer specific. I rarely have structures with roof that I have to specify (we usually use third party metal builder)

Anyway, in this industrial shed I have specify everything. I thought 24 gauge R panel roof have standard capacity and not manufacturer specific? Where can I get R panel "standard" capacity formula similar to the table?

 

[delagina]

P1eng - is that spreadsheet in aisi website? I'm located in the US

 

[P1ENG]

delagina,

No, that snapshot is from my MathCAD library. Nothing is hidden, so you could easily reproduce it in Excel if you like. If you want generic, then that calculation is for you. As far as generic span table, it will greatly depend on the profile of the deck and AISI checks are not something "generic". Hand calculations will require an iterative design process. I use a program called CFS to check formed sections, but it is not free. If it is the metal builders livelihood to bend decks, then they should be able to provide you with span capacities. If they just happen to be some outfit that has a roll former, then you need to make sure you specify minimum thickness and yield/ultimate strengths of coils.

Juston Fluckey, SE, PE, AWS CWI
Engineering Consultant

 

[delagina]

P1ENG,

I don't know who the contractor will use to buy the roof panel.
How do I get the capacity " 24 GA "R" PANEL " without being manufacturer specific.
If you can link me to the formula for this, I'd appreciate.

Thanks,

 

[P1ENG]

I don't think there is such a thing. Do all 24 GA "R" panels have the same profile shape? I would say no. Again, calculating the bending strength of a formed section is not an easy, 1-formula process.

Juston Fluckey, SE, PE, AWS CWI
Engineering Consultant

 

[delagina]

How do you suggest I go about this.
I need to show in my drawing the type of roof to use.
I guess I'll just specify the manufacturer and say approved equal?
This is just a simple industrial shed. I didn't realize there is no "standard" R panel roof capacity or formula.
I'm looking at a goby drawing and it just specified, 24GA "R" panel. Not saying the goby is correct though.

 

[P1ENG]

List the uniform load on the panel and its span. Then give the option for a specific panel that works and put the responsibility on others if a different panel is chosen. Like the below:

Uniform Load on R-Panel = XX psf
Maximum Span of R-Panel = X'-Y"
Use 24 GA (pick a manufacturer that will work) R-panel or equivalent. Owner responsible for verifying equivalent load capacities for the given span with the manufacturer of the equivalent panel.

Juston Fluckey, SE, PE, AWS CWI
Engineering Consultant

 

[delagina]

thanks,

 

[ajh1]

The uplift capacity on the fastener is generally going to be one of two things:
1) fastener pull-out driven by screw diameter and thickness of supporting steel
2) fastener pull-over driven by screw head or washer diameter and the thickness of the roof panel.