Web joist

[jenofstructures]

good day to all of you

im designing a building using web joist as a part of roof.
I already have the loads that i need for the joist and found a web joist that suit for this (i used vulcraft).

the problem is, i want to know the properties of the said web joist but i just can't see the geometric sizes that they are gonna use.

can please be anyone of you have some properties of this material?


thank you very much

 

[paddingtongreen]

The term is "open web joist". What information do you want that isn't in the tables?

Michael.
Timing has a lot to do with the outcome of a rain dance.

 

[jenofstructures]

the sizes of the member of the joist

 

[msquared48]

Should be in the Vulcraft design manual.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[jenofstructures]

no, vulcraft only gives the name of the joist(either k series, LH or DLH), its depth,series number, and its load tables.... They also gives the requirement and members of bridging. But i need the member that they are gonna use for a certain joist

lets say i chose 20LH01,it only shows that the depth of the joist is 20" but it didn't tell whats the member comprising the 20LH01. Like the top chord and bottom chord used
for the certain joists.

 

[jenofstructures]

i also have an additional question regarding open web joist

is the note on vulcraft manual,4.7 Camber (pg 25) showed the recommended camber for shored?or it is unshored?

thank you very much

 

[msquared48]

The "01" in the nomenclature is the chord size. Typically ranges fro 01 to 12. In that the 01 is not translaterd in the manual to an actual member as you mentioned, you will probably have to call Vulcraft.

What bugs me is that I found it years ago, but cannot now. May have been in an older manual I wore out.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[dik]

Unless you have snow accumulation or strange loading for a 30 to 40 psf live load, the joist depth will be approx 0.7 * span (in inches), ie, a 30' span would use a 22" deep joist...
as a reasonable guess.

Dik

 

[SteelPE]

We had a similar question a few weeks ago.

http://www.eng-tips.com/viewthread.cfm?qid=261921

The only way you are going to get the proper information is to call manufacturer. Sometimes they are helpful… other times not so much. Good luck.

 

[spats]

Joist manufacturers have never published chord and web sizes, as far as I know. There's no such thing as a standard angle that represents a chord size "3", for instance. Each manufacturer, and even each plant of a particular manufacturer, such as Vulcraft, can have a different standard. Many times it even depends what's in stock at the time of fabrication. Most manufacturer's have proprietary angle sizes made especially for them, so you can't even assume they're using standard angle sizes out of the steel manual.

All you can do is estimate sizes, using some simple math and a double angle column capacity table. The manufacturer should be able to tell you what angle size is designed for a particular situation, but my understanding is that the shop can always substitute heavier sections.

 

[JedClampett]

jenofstructures, if you're looking to verify any joist information, you're going to find it very difficult. If you want a 24 inch deep joist that's good for 100/300 (100 lb per linear foot DL, 300 lb per linear foot Total Load) the joist manufacturer will provide you exactly that. But if you want to dig into the specific properties of the joist, you can either specify a KCS joist or keep bothering the joist manufacturer until you get an answer or die trying. As earlier posters have said, for various reasons, joist manufacturers are very stingy giving out information.

 

[paddingtongreen]

jenofstructures, if you are looking for clearances, your best bet is to show your needs on the drawing. Manufacturers don't limit themselves to fixed section sizes, if they get a good deal on something that works, they will use it. If you tell them your clearances, your point loads etc. they will re-arrange their web framing to suit, or they will come back to you with alternative suggestions.

Michael.
Timing has a lot to do with the outcome of a rain dance.

 

[jenofstructures]

thanks guys for the information
i already thought of this because if the manufacturer gave you their properties and sizes, it will limit their job because contractor may be used this to manufacture their own open web joist