Re: Guide to use of Lally (Lolly) columns.

fredfighter@xxxxxxxxxxx wrote:
RicodJour wrote:

Perhaps I was unclear. I have sized the beams already, I need to size
the columns and their footers.

It was a bit unclear. The first couple of posts made it sound like you
didn't think the beam was involved with the column spacing.

You'd be wise to take marson's recommendation and fax/email a sketch of
what you want to do and have the yard work up a solution. It's a free
service.

I may do that to size the footers. I'll check at 84 lumber later
today.

I doubt that a lumberyard will give you that information. The
beam/column stuff is part of the engineered lumber design software.
Foundations aren't.

You need to determine the type of soil you have, deteremine its
capacity and then just make sure you have the right distribution area
for the footer.
http://www.concretenetwork.com/concrete/footing_fundamentals/why_soils_matter.htm
Use a suitably large factor of safety, at least 2.

{snip}

There are permanent adjustable steel posts with the screw
adjustment at one end (doesn't matter which end you put it on), and
there are steel pipe columns that are fabricated to size.

Yes. If it weren't for building codes I'd design and make my own.
I expect a building inspector will not sign off on a homemade column.

It's not much of a design, really. Pipe cut to length, top and bottom
cap plates, drill some holes for the bolts. Frankly, I don't know how
the inspector would be able to tell who made the columns. They all
look the same and are painted primer red.

Each
manufacturer has their own load tables.

This chart gives generic information:
http://www.engr.uga.edu/service/extension/publications/extengrhndbk/General%20Structures%20INformation/Building%20with%20Steel/D2.1.pdf
This gives information on one specific brand of column:
http://www.icc-es.org/reports/pdf_files/BNBC/93-36.02.pdf

Excellent, that is just what I needed. There are literally hundreds
of webpages about Lolly columns that are devoid of useful information.

It's all in the search terms.

There are many factors involved in sizing structural members. Rarely
is it as simple as picking an item from a chart. Most times people
can't even figure the loads properly - pretty much makes it impossible
to design a solution.

Last I heard, none of the equipment I designed for nuclear power
plants has had any structural (or other) failures. I think I can
handle my addition.

The question you initially asked about spacing of the columns was
phrased in a way that made it seem like you didn't understand the
correlation between beam strength and column spacing. Later you said
you had sized the beam. That was confusing - if you sized the beam,
you had to select a span, which gives you the column spacing and would
mean that you had already answered your own question.

I emphasize safety, whether in the design or actual construction. I've
seen too many accidents and had to clean up too many messes to do
otherwise. Giving advice over the internet is a crap shoot sometimes.
You never know if the person asking the question really understands
what is going on, or whether they've just googled and picked up some
buzzwords so the questions sound professional.

Good luck with your addition. What exactly are you building?

R

.

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