When were *light gauge* lally collumns introduced?

[DavidKn]

Does anybody know when they stopped making "lally columns" from structural (standard) pipe, concrete filled, and switched to the current 16 GA shells? I am looking at 1987 plans for a building that calls for 3-1/2" lally columns. When I calculate the load, it is more than twice what I would put on a modern lally, but for the old-style lally, it would be no problem. I'm only increasing the load about 3%... but still! The cap plate and the footing called for would be good for the full load.

 

[madmantrapper]

I don't know what you are working on but I started building residential in the early seventies and never seen a concrete filled lally column. I worked on many homes built in the early nineteen hundreds thru the seventies and have seen plenty with heavy steel pipe columns but not filled.

 

[DavidKn]

Concrete filled lally columns are very common in Massachusetts, at least in Eastern MA. Maybe that's because John Lally lived in Waltham. From the beginning of the 20th Century up through at least the 1930s or so, they were made with structural steel pipe. I've replaced many of them that were rusted out in wet basements (after 50 years or more), and it is easy to see how they were made. Current ones are 16 Ga steel shells, concrete filled. You can buy them at any lumber supply store. You can cut them to length with a sawsall. But they are not as strong as the old ones. I am trying to find out WHEN the change was made. I've talked to one lally supplier, so far, who says they switched to 16 GA back in the 70s, and before that they used 11 GA (about 1/8"), and that the structural pipe lallies were before his time. So I've narrowed it down, somewhat.

 

[XR250]

Why do they fill them with concrete?
To prevent the 16ga shell from buckling or is it for fire resistance?
I can't imagine it being as economical as simply going to a heavier gage.
The ones I bought recently at Lowes were about 12ga and hollow.