Hi All – I have a huge 1875 home in Eastern MA. I’m digging out and replacing the basement floor (it’s barely an inch thick, missing completely in some areas, and this is part of an overall solution to control water in the basement). In the course of doing this I’m wondering if I should replace 9 screw-type posts with steel/concrete lally columns, for two reasons: first, I read somewhere that the screw-type post is not intended to be permanent. Second, I have no confidence that they are sitting on solid footings – they may in fact just be sitting on an inch of concrete.
The house is reasonably level and stable (as level as a 135 yo house can be!), and the posts are not rusted out (this may just be a sign that they were added recently).
I’ve done this before so the actual process of replacing the posts isn’t daunting to me. I just think it makes sense to do this now rather than excavate and pour a new floor around the existing (sub-standard?) posts.
Thoughts? Thanks!
P.S. If I DO go ahead with this my plan is to pour the top of the new footings about 4″ below the expected finished floor level, set the new posts, then pour the floor around them. I’m assuming I should still rest the posts on the steel plates provided with them, even though the new floor will anchor the lally columns and the plates will be buried in concrete. Correct?
Replies
Lally posts
You are right about preparing footings for the support columns. However, you do not want to encase the steel columns in concrete. Best to keep the steel separated from the concrete with a plinth block to avoid corrosion, and to allow for the removal/replacement of a column in the future.
Just pour footings prior to floor and reinstall the columns when you're done. How do you keep the ceiling (next floor) supported while doing this? By doing the floor a bit at a time.
Have fun!
It is, however, common practice in many areas to just pour the floor around the posts.
The other reasonable alternative is to pour footings for the posts flush with/proud of the finished floor level, install the posts, and then pour the floor around the footings. This is best in many ways as the floor and footings can be isolated from each other to a degree.
To the OP: Some screw posts are designed to be permanent, some aren't.
bill
The sleeve type telescoping posts with pins are not recommended. HUD approved screw type (ordered within 3" adjustibility) are fine for what you propose.
Lally column
You want to pour a good footing first. Under normal conditions the bottom of the column will not have any issues in our life time. If that is a concern either put a good metal paint or roofing tar on the bottom of the column. Encasing the column in concrete is the best way to install the column. You should never have to replace the column again.
The bottom plate should always be used because it is spreading the weight out over the footing not creating a point load where the column sits. If you plan on pouring a 4" slab I would recommend using our adjustable base set. It carrys 55,00# you can adjust it up to 3" and it will get covered in your floor.
As for the hollow columns our there, the 3" 11ga single shaft adjustable columns are code compliant for perminant use. The two piece jack post are not allowed for perminant construction.
You can find out more info on our website http://www.deancolumn.com If you have any questions please contact me on our website. Good luck.
David
David
It would seem to me that he could get very good information and the columns at a good lumberyard. You know, shop local for a very available product?
Where would your company do a better job?