Cutting and installing lolly columns
musashi
| Posted in Construction Techniques on
Hello:
I have recently bought a 1915 attached 2-story brick house, and the main beam in the basement needs some support. I am going to put in concrete-filled, steel lolly columns. There is a concrete slab in the basement, which I will chip away where I want to put in the columns, and make new concrete footings for them.
My questions are these:
* How big and how deep do I have to make my footings?
* How can I cut the columns to length? Will a Sawzall do it, or do I
need a chop saw with an abrasive wheel?
* Any tips for fine-tuning the height? It will be hard to get an
absulutley perfect cut.
Thank you for any tips or suggestions that you might have.
Alex
Replies
Generally we pour the footers 8" deep. You cut the columns with a large pipe cutter. Many suppliers have one they will loan out. You can cut them within a 1/32". Often they will leave some concrete that is uneven with the cut, just chip it flush with a few hammer taps.
Beat it to fit / Paint it to match
IMHO, 2 story brick house I would go at least 18x18 or even 24x24 plus rebar with 3500- 4000psi mix. When it comes to digging and concrete I only want to do it once.
YMMV
The awful thing is that beauty is mysterious as well as terrible. God and the devil are fighting there, and the battlefield is the heart of man.
- Fyodor Dostoyevski
I've only put a steel post in once. And it was not filled with concrete. So this post may be worthless to you...
I ordered the post long by four or five inches and had flanges welded at the ends.
I dug the hole for the footing (1'x2', 30 or so inches deep) and put the rebar in. I jacked the beam up to where I wanted it with jacks on both sides of where the post was going.
I bolted the post to the beam so it was now suspended above the hole and extended down into it. I filled the hole with concrete, burying the bottom of the post.
The second steel post at the front of the pic is there to run from the bottom of the hole to about three feet above the floor surface and filled with concrete to protect the post from cars (this is a garage).
Rich Beckman
Another day, another tool.
Edited 1/17/2005 11:44 am ET by Rich Beckman
Most of the advice above seems reasonable. As long as you don't have unreasonable loads, 30" x 30" x 12" should be plenty. Add a few pieces of rebar criss-crossing the center. Keep the footing a few inches below the top of the slab, so later you can patch the floor and lock the column in place. Make sure you allow the concrete to cure a few days before positioning the column.
The few times I've cut lally columns, I wrapped a piece of paper around the column at my cut mark to mark a neat circumference. I used my Sawzall with a metal-cutting blade (Carbide abrasive blade worked great) to cut through the steel, and then snapped the core with a hammer blow and a few taps to tidy up the end.
You should be able to get your length to within an eighth or so. Use a hydraulic jack to raise the beam just enough to slide the column and its steel plates into position. You might have to persuade the column plumb the a hammer and block. Then let the beam back down.
Al Mollitor, Sharon MA
To all of you that have offered suggestions:
I appreciate your help very much. I now feel more prepared to tackle the job. Thanks.
Alex, Brooklyn, NY