Installing a Lally Column - Contractor Talk - Professional Construction and Remodeling Forum

BCFBeacon · 02-25-2008, 08:26 PM

One of my friends recently hired and essentially fired a contrator to dig up his existing basement slab, put in a french drain and sump and replace an existing lally column. I shouldn't even say it was a lally column. It was more a glorified floor jack sitting directly on the old slab. Long story short, the contractor put in the drain and dug out a spot for the footer (I checked it out before they poured to make sure it was the proper size/depth). For some reason the contractor never poured the footer/never installed the column and just poured the new slab. Now the contractor is MIA. I have seen columns put in but have never done it myself and never seen it done without a footer. I know how to cut the column but wasn't sure how long to cut it (i.e. exact length, slightly longer. If so, how much longer). Also, how big (thickness and area) should the top and bottom plates be? This is essentially a root cellar in an early 1900's house, so we not talking about a big space. Any help would be appreciated.

Patrick · 02-25-2008, 08:30 PM

Generally, lay the steel plate on the floor, measure between the plate and the beam. cut your column and then use a jack to just lift the beam up a hairs width to slide the column in with the plate on top.

neolitic · 02-25-2008, 08:31 PM

Do you need to take some sag out
of the beam now?

A W Smith · 02-25-2008, 09:10 PM

I have always set the column so it is captive in the slab on top of the footing. Although I saw Tom Silva do it wrong on "ask this old house." After having the homeowner basically excavate a proper 2 x 2 footing under the slab. Tom had him fill the hole with concrete right to the top. I said to myself "WTF Tom!!? your supposed to do it in two pours!!" Then he proceeds to cut the column with his column cutter and sets it right on top of the slab where it could potentially fall over if there's movement.

neolitic · 02-25-2008, 09:16 PM

We buy 'em from a masonry supply
cut to length with top and bottom
plates welded, then screw
the top to the beam, and tapcon
the bottom plate.

But it sounds like the OP may need
to string the beam and jack it up
to straight, since the old one has
been out for awhile?

philner · 02-25-2008, 09:46 PM

I have my plates welded on at a local machine shop for $10 a pop. I will encase the bottom in the slab when convienent(wrap sill seal around the column so the expansion and contraction doesn't crack the slab) But will tapcon if needed. I would suggest checking the girder with a string for staight, The old lally wasn't replaced because it was in great shape. Phil

BCFBeacon · 02-26-2008, 06:34 AM

Thanks for the help. The beam currently has very little sag. The span is actually pretty short (approx.10ft) and the original beam is in very good shape. This is more preventative/homeowner piece of mind. One more question - should the bottom plate be the size the footer was supposed to be or are plates pretty standard size? Thanks again.

neolitic · 02-26-2008, 07:52 AM

If you buy the column from a masonry
supply they have standard sizes to
match the column (3",4",6",...).
If you go to a fabricator or machine
shop I guess they can make whatever
you want.

Railman · 02-26-2008, 08:18 AM

Around here it used to be common to do thickened slab footers for lally columns, but not any more. The main reason for the change is accountability. Inspectors want to see the pads when they do the footer soil inspection. As long as the footer area match's the column, there shouldn't be a problem.

Joe

tom m · 02-26-2008, 11:18 AM

I did one a month or so ago. You dig the footing below the slab and pour it below the slab. Then you position the new column at its location and lock it in with the slab /top pour. They make adjustable for this reason, you bury the adjustment part with-in the slab top coat. I poured mine all at once slab and footer. I did not use an adjustable and I had a large steel wrap around connector. So I had to position it in place then hold it up there! I did that by making clamps out of 2x4 that bridged the hole and used carriage bolts to draw the lumber together around the pole so it doesnt drop. This is a pain in the azzzz but i made the pour all at once time is money.

Railman · 02-28-2008, 12:19 PM

I see post with the screw on top almost daily. As a matter of fact my home is that way. There's nothing wrong with it that way, unless a good screw scares ya!

Joe

MALCO.New.York · 02-28-2008, 12:32 PM

Definitely like a good screw top or bottom. From my Women (as long as she is not too heavy) or my Lallys. I prefer my Lallys on top.

big steve · 02-28-2008, 05:11 PM

Did you consider adding to the beam and eliminating the column. if its only a 10 foot span you could probably add an lvl through bolted.Check your loads .if you call georgia pacific , they have people who can help you calculate what you need.As for the footer, i have seen the slab and footer poured together but you need to cut the slab around the column to control any cracking.This is not the way i do it but i gues it works
Good luck, Big Steve

philner · 02-28-2008, 05:47 PM

Adjustable screw type columns are for temporary use and not meant to be permanently installed.

skymaster · 02-28-2008, 06:03 PM

Not legal here unless you weld the screw.

Railman · 03-21-2008, 06:15 PM

http://www.qualitywayproducts.com/qw...escription.htm

If you read the specs, they say their posts surpass all local, & national codes, with the screw either way, & have been tested by an independent engineering co. as such.

I know for a fact that they are legal, & used widely around here, with the screw on the top. I don't know about anywhere else.
Joe