Architecture - lally columns

hey guys,

i have lived and worked in the SW my whole life where homes are mostly slab on grade..i'm going to be building a home with a basement which requires lally columns down the center of the basement to support the center girder for the first floor subfloor..

? 1) my limited understanding is that lally columns are 3 or 4" concrete filled steel pipes on/in footings for support..is this something custom made by a steel shop or can they be bought in various lengths?..

? 2) are the extend-o columns a common alternative?(rated 13,000 to 15,000 lbs each)

i've not received an answer from my home mfgr and would like the adjustability of the extend-o's..

all i do know is that the home has a 30'x40'x8' basement with 5 of these columns running down the long dimension..40# live load on the first floor(what is live load?) and 30# live load on the second floor..

i'm not asking for anything but what's common practice...TIA

The adjustable lally columns are a common alternative and with 5 along a 40' legnth you should have plenty of support. Keep in mind that the adjustability is only for the initial setting of the columns and beams and you should not adjust after that. Live load refers to loads like furniture, people, appliances, etc. - Dead loads refer to the weight of all building materials of the house like the joists, subfloor, walls, finishes, etc. - both must be accounted for in sizing structural members.

thanks for the reply 2nd cut..i am still waiting from the home mfgr as to weather these are a suitible/adequate sustitute...the home will be a milled log kit and i will have 2 weeks vacation to get the subfloor built and the logs up to about 4'..then i have someone else taking over to get it dried in..

if i use the extend o's i can buy them now, because i have a very good idea what i will need for height, bolt them down after the basement's poured, build the perimiter box, pull a string, blah blah blah...you know...

thanks again,
william