Delta Joists by Butler
Delta Joists by Butler
(OP)
Hello all,
I have some drawings of an existing warehouse that I'm hoping to hang some equipment from the ceiling in. Unfortunately the drawings with the specific joist information are missing (or was never given to us because it's proprietary). The cover page says it's a Delta Joist system by Butler and are "1/4:12DS / Full Delta" joists.
Does anyone have any information on these? Or is my only hope taking some site measurements?
All other posts on the subject don't seem to offer any design help, only identification.
Thanks in advance,
Adam






RE: Delta Joists by Butler
RE: Delta Joists by Butler
RE: Delta Joists by Butler
RE: Delta Joists by Butler
RE: Delta Joists by Butler
EIT,
VA, USA
RE: Delta Joists by Butler
Mike McCann, PE, SE (WA)
RE: Delta Joists by Butler
RE: Delta Joists by Butler
However, it was never made clear to me if he was actually the "only" engineer they had on staff, or if he was the only one that had dealt with my particular project type. I would hope they have more than one semi-retired engineer.
EIT,
VA, USA
RE: Delta Joists by Butler
The greatest trick that bond stress ever pulled was convincing the world it didn't exist.
RE: Delta Joists by Butler
al..
RE: Delta Joists by Butler
Well, there you go. I guess that is why Ben Franklin said “Believe none of what you hear, and only half of what you see.”
EIT
RE: Delta Joists by Butler
RE: Delta Joists by Butler
@ajh1,
I am looking for as much information as possible. Since we are looking to hang equipment, any material or section properties/dims or load tables if available. Or the availability of these items...
Any information to aid in coming to a conclusion whether it's safe or not to hang the units. The building was build in 1999.
Additionally, does "1/4:12DS" refer to a specific joist configuration?
What does a full Delta joist refer to?
Is there any unique challenges with this system?
Attached is an image of the joists, not specifically where we will be hanging equipment.
Thanks in advance,
Adam
RE: Delta Joists by Butler
I believe the "1/4:12DS" simply means 1/4:12 roof slope on a double slope building, although I will verify that.
A full Delta Joist is one full V (2 trusses with appropriate bracing).
The Delta Joist product is basically a bar joist installed at a 45 degree angle to the vertical. The top and bottom chord are single hot-rolled angles that are installed such that when the truss is placed at 45 degrees the legs of the chord are perpendicular and parallel to the roof plane. The chord sections are screwed together along their length.
The product was developed to provide a diaphragm-capable structural system so that we could place our standing seam roof on top as a direct swap for bar joists and a diaphragm deck without having to completely redesign the bracing systems for a conventionally designed building.
If you want to reach me direct, use the following email: ajharrold at butlermfg dot com
I will try to post some of the more generic information here on the forum so others can gain some insight as well.
Al..
RE: Delta Joists by Butler
I would like to comment in general on past order retrievals. Butler uses one of the many underground storage areas here in the Kansas City area, and yes a number of years ago there was a serious fire in the cave we for storage. To my knowledge I have never had trouble getting a file retrieved, although a few have come back encased in plastic bags with latex gloves provided and smelling like they came out of the fall leaf burn pile. The bigger problem on retrieval is simply lack of information to make the request. The two BlueScope Buildings brands (Butler and VP) process somewhere on the order of 5000-7000 orders per year. Our retention policy is that all orders are retained in storage for the lifetime of any warranties on the building. Our primary roof systems now have an available 25 year warranty, so typical retentions are in the 20-25 year range. If the building is older than that I'm sorry, but we won't be able to retrieve it. If you figure that the typical order will have a file folder in the range of 1"-2" thick (much more for some of the large custom jobs) you can appreciate the number of boxes that make up 20 years worth of orders. The last job I pulled had 2 full boxes for that one project.
If you can't reasonably identify the job location, approximate date of construction, and/or the original end customer the chances that we will be able to find the order are slim. If you can somehow come up with some of the original erection drawings (either from the contractor who built the building or the owner)and can pull the Butler order number from those, the likelihood that we can find the order in the archives goes up tremendously.
Al..
RE: Delta Joists by Butler
As an aside to one of my previous posts, I misspoke somewhat regarding the definition of "Full Delta". Towards the end of the period that this product was on the market we created a "Hybrid Delta" option. Delta Joists were used around the perimeter of the building to the extent required to provide sufficient lateral bracing in both directions. The center portion of the roof was filled with our truss purlin product as a cost savings measure. The ultimate problem with the Delta Joist product was that it basically required 2 joists for each joist location and thus was overly expensive unless you were supporting extremely high snow loads, hence the attempt to minimize the Delta requirement on the building.