"Lally" columns
We have a slightly sagging point at the rear corner of the basement level. I’d like to put a support to raise it an inch in the cellar. I went to two construction supply places and they both have posts in a box that you assemble called Tiger. They were very unimpressive sheet steel tubing….
We have a slightly sagging point at the rear corner of the basement level. I’d like to put a support to raise it an inch in the cellar. I went to two construction supply places and they both have posts in a box that you assemble called Tiger. They were very unimpressive sheet steel tubing.
Where should I be looking for a single piece cast iron tube with a threaded adjustable stem at one end? (see screengrab drawing) I thought they were the standard thing, but the sales guys at these places tell me everybody uses this cheesy steel thing.
really it is good
Are you sure you want to raise a sagging section? Won’t that crack all the plaster in the rest of the house?
HDL,
When the time comes I’ve got some 20 ton jacks you could probably borrow.
bruce at jerseydata.net
Sorry. I should have added thay my house is less than 17 feet wide. Also there is no sag at all.
Bruce: I think you’re right I’ll need to use some sort of jack to get the temp posts adjusted to take the weight off the column otherwise some sort of settlement will occur.
JimHill: I agree something to distribute the load is necessary.
Thanks.
HDL
You need to hydraulic jack, or at a minimum wedge beam uprights (minimum 4X4’s) to temporary shoring joists.
Joists like to go down, they don’t like to go up. You don’t want to lose any “straightness” you now possess.
This is why I recommended used joists as temporary shoring. In a pinch, cut-off lengths of paralam will do.
You will need cement filled column,, hung from above, sonotube filled with cement, and backfilled with cement flush to slab. And the cement needs a few days to cure. Just because it feels hard to the touch doesn’t mean it is ready to support a house.
bruce at jerseydata.net
Without seeing the conditions, I would suggest that the beam is there for a reason, be it support of the stair framing where joists are headered off, or perhaps there were stiffening walls in line with that beam and they were taken out by a previous occupant. To that effect, are the floors sagging around the stairs? If so, how much, and is it worth looking into fixing?
The temporary posts will be fine on the existing slab if you put something in to distribute the load a little. Just a 2 foot section of a 3×8 floor joist or something like that would suffice until the real column is installed. Without it, they could poke through the slab.
I have a related question.
In my cellar I have an old brick and mortar column. Water seems to seep in at the junction where this column meets the floor. Ive been told that to fix this properly I’ll neet to support the timber beam in the basement on either side of the column with jack posts while we demo the old column, pour a proper footing that is tied into the floor slab properly and repace the old column with a steel column as JimHill describes before removing the temporary jack posts. Im trying to figure out just what that timber beam is supporting. The house has no bearing wall above this beam as most homes greater than 17′ usually do. So its really only the floor joists for my garden level how much can that really weigh? Would it be too much for the jack posts to support on the slab with no footing even temporarily?
Yes, what bruce, jim and jock said. We had to replace some of the se adjustables with real lally columns. Don’t screw around with structural support.
I had a contractor install these on a job once, instead of standard lally columns. They got rejected and he had to replace them. A true lally column is usually a hollow steel tube filled with concrete to prevent it from buckling, and sitting on a concrete footing.