Question:
The house we recently bought has a central beam in the ceiling of the basement running the whole length of the house, with two brick pillars holding it up. At some point, someone put in a 4×4 post midway between the brick pillars for extra support. The housing inspector recommended that we replace the 4×4 with a steel lally column. The bottom of the 4×4 gets wet when it rains, which isn’t very often. Anyway, how does one go about installing a steel lally column? Home Depot seems to have only one length of lally columns, and they come pre-filled with concrete. Is that normal? I though that one would put the thing up and then fill it. Does one normally get a precut, pre-filled column for such an application? Do I need a house jack to install it? The 4×4 has an extra piece of wood between the top of it and the beam it supports. Do I do something like that and hammer in a shim after placing the lally column? Are there any books that explain this sort of thing? Thanks for the help. scott — Scott Stuart stuart at ll mit edu
Response:
Lally columns are sold in standard lengths and they are all filled with concrete. There’s a special tool used to cut them. It’s basically a giant pipe cutter. You cut only through the metal and the concrete just snaps off. A hammer is then used to knock off any jagged concrete. You could probably accomplish the same thing using a hacksaw to cut all the way around the circumference but it’ll take awhile and the cut won’t be as "clean". You don’t need a house jack. Use a scrap 4×4 or double up some 2×4s. Make the length slightly longer than the distance from the ceiling beam to the floor. The wood will be a slight angle and simply by hammering it towards an upright position the ceiling will be raised slightly. Once the lally column is in place you just knock the temporary support out. You shouldn’t use shims on either end of the lally. There are square metal plates about 4" on a side that are used. The metal plates need to be nailed to the ceiling and floor. You’ll need a ramset or Hilti gun to nail into the concrete slab. Technically, underneath the lally column should be a footing (or footing under the slab). You probably don’t have this since the support was added after the fact. You may need the distribute the weight out over a larger area to prevent the slab from cracking. A small piece of pressured treated lumber (2×8) would probably work. Make sure it is secured to the floor also. I have 2- 8 foot lally columns if anyone wants them for free. They’re heavy! -al sung A Sung Consulting (Hopkinton,MA) – Hide quoted text — Show quoted text -> The house we recently bought has a central beam in the ceiling of the > basement running the whole length of the house, with two brick pillars > holding it up. At some point, someone put in a 4×4 post midway > between the brick pillars for extra support. The housing inspector > recommended that we replace the 4×4 with a steel lally column. The > bottom of the 4×4 gets wet when it rains, which isn’t very often. > Anyway, how does one go about installing a steel lally column? Home > Depot seems to have only one length of lally columns, and they come > pre-filled with concrete. Is that normal? I though that one would > put the thing up and then fill it. Does one normally get a precut, > pre-filled column for such an application? Do I need a house jack to > install it? The 4×4 has an extra piece of wood between the top of it > and the beam it supports. Do I do something like that and hammer in a > shim after placing the lally column? Are there any books that explain > this sort of thing? > Thanks for the help. > scott > — > Scott Stuart > stuart at ll mit edu
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