# Exercising against the floor jacks supporting our house **URL:** \ **Category:** Factual Questions\ **Created:** [December 19, 2022, 12:05am UTC](https://boards.straightdope.com/t/exercising-against-the-floor-jacks-supporting-our-house/976755 "2022-12-19T00:05:02Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![Caribbean\_cruiser](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/caribbean_cruiser/32/9349_2.png) [@Caribbean\_cruiser](https://boards.straightdope.com/u/Caribbean_cruiser)\ **Post date:** [December 19, 2022, 12:05am UTC](https://boards.straightdope.com/t/exercising-against-the-floor-jacks-supporting-our-house/976755/1 "2022-12-19T00:05:02Z")
Yes, I know this sounds bonkers but I want to know if it’s very very safe to lightly lean against one of my basement floor jacks (which are set in concrete at the base and hold up one of several structural I-beams, up top) as I do squats using a light 30-lb dumbbell, mainly for support in case I lose my balance. Another exercise finds me using exercise bands, attached to the floor jacks, to do back exercises. Note: I am not Lou Ferrigno, nor do I turn green when angry. I’m just looking for some support as I exercise in a small, unfinished part of my basement, and I don’t want to lean against drywall and scuff the paint. (Yes, I just said that.) Please tell me I have nothing to worry about. Comments from rescue dogs are not welcome! ---
**Author:** ![Princhester](https://avatars.discourse-cdn.com/v4/letter/p/3e96dc/32.png) [@Princhester](https://boards.straightdope.com/u/Princhester)\ **Post date:** [December 19, 2022, 12:25am UTC](https://boards.straightdope.com/t/exercising-against-the-floor-jacks-supporting-our-house/976755/2 "2022-12-19T00:25:29Z")
If you could push over posts set in concrete and holding up your house, your house would already be unsafe and you would need to get out now. A light breeze on one wall of the house would exert more force than you leaning on it. You couldn’t push it over with ten men. ---
**Author:** ![Isilder](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@Isilder](https://boards.straightdope.com/u/Isilder)\ **Post date:** [December 19, 2022, 1:20am UTC](https://boards.straightdope.com/t/exercising-against-the-floor-jacks-supporting-our-house/976755/3 "2022-12-19T01:20:41Z")
That is NOT so. What happens is that the soils under the foundations expand and contract, eg with water… So at one point of time the jack may be unloaded. Plenty of redundancy in the jacks and piles and other foundations… Or maybe this jack just never got loaded much… the beams just haven’t settled down onto it ? What has to be is that the jack must be securely held at top and bottom, so it won’t slide out . The top may be just inserted under a bouncy beam. The floor structure is designed to bear loads, not to resist being lifted. The beam on the jack may lift and let the jack fall ? ---
**Author:** ![OldOlds](https://avatars.discourse-cdn.com/v4/letter/o/a3d4f5/32.png) [@OldOlds](https://boards.straightdope.com/u/OldOlds)\ **Post date:** [December 19, 2022, 1:38am UTC](https://boards.straightdope.com/t/exercising-against-the-floor-jacks-supporting-our-house/976755/4 "2022-12-19T01:38:05Z")
I’m not a structural engineer. That said, it seems to me that if one of those jacks (I assume lally columns) is so unloaded that you can knock it over, it wasn’t bearing much load in the first place. That might be an issue in and of itself, but I think you’re fine. ---
**Author:** ![Princhester](https://avatars.discourse-cdn.com/v4/letter/p/3e96dc/32.png) [@Princhester](https://boards.straightdope.com/u/Princhester)\ **Post date:** [December 19, 2022, 2:05am UTC](https://boards.straightdope.com/t/exercising-against-the-floor-jacks-supporting-our-house/976755/5 "2022-12-19T02:05:01Z")
It’s concreted in. Can you push over a concreted in post? Are you the hulk? It’s either firmly in place or doing nothing ---
**Author:** ![ZonexandScout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zonexandscout/32/544_2.png) [@ZonexandScout](https://boards.straightdope.com/u/ZonexandScout)\ **Post date:** [December 19, 2022, 4:20am UTC](https://boards.straightdope.com/t/exercising-against-the-floor-jacks-supporting-our-house/976755/6 "2022-12-19T04:20:27Z")
Every jack I’ve ever seen has the top plate screwed in place on the floor joist or beam. If the bottom is secure, it will be quite difficult to move the jack. ---
**Author:** ![Caribbean\_cruiser](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/caribbean_cruiser/32/9349_2.png) [@Caribbean\_cruiser](https://boards.straightdope.com/u/Caribbean_cruiser)\ **Post date:** [December 19, 2022, 6:58pm UTC](https://boards.straightdope.com/t/exercising-against-the-floor-jacks-supporting-our-house/976755/7 "2022-12-19T18:58:42Z")
Yes, these structural posts are definitely concreted into the basement floor. Rapping them with my hand suggests they are as solid as solid can be. A label on one says it is rated to support up to 15,400 lbs, which is slightly more force than I can generate. The top of these “lolly columns” is not actually screwed to the I-beam but rather it has thick metal “ears” that are bent over so as to grab the I-beam and prevent slippage. I think this answers my question. Thanks one and all. ---
**Author:** ![Dewey\_Finn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dewey_finn/32/4222_2.png) [@Dewey\_Finn](https://boards.straightdope.com/u/Dewey_Finn)\ **Post date:** [December 19, 2022, 7:10pm UTC](https://boards.straightdope.com/t/exercising-against-the-floor-jacks-supporting-our-house/976755/8 "2022-12-19T19:10:00Z")
[Lally column](https://en.wikipedia.org/wiki/Lally_column), actually, not lolly column. ---
**Author:** ![md-2000](https://avatars.discourse-cdn.com/v4/letter/m/9d8465/32.png) [@md-2000](https://boards.straightdope.com/u/md-2000)\ **Post date:** [December 20, 2022, 5:25am UTC](https://boards.straightdope.com/t/exercising-against-the-floor-jacks-supporting-our-house/976755/9 "2022-12-20T05:25:57Z")
> [@Caribbean\_cruiser](#): > > Yes, these structural posts are definitely concreted into the basement floor. > [@ZonexandScout](#): > > Every jack I’ve ever seen has the top plate screwed in place on the floor joist or beam Yes, these things usually have a U-shaped or flat plate top. Regardless, this should have screws attaching it to the floor beam (through holes in the plate for that purpose). If the house or ground shifts so you can knock these over, then it could just as easily unload enough to fall over. Most such jack posts I’ve seen are not cemented in (in case replacement is necessary) but also bottom plate is bolted into the cement or the bottom plate is just sitting there. Every so often you should check to be sure the house is not sagging where these posts are (giveaways like hard-to-close doors, or does a marble want to roll pretty fast to a certain point?) If the house is settling, you can give the jack a fraction of a turn (or more) to help level that area of the house. But previous posters are right - if you can pull this down with moderate effort, it’s not really a support and suggests the house could start sagging in that area. ---
**Author:** ![jjakucyk](https://avatars.discourse-cdn.com/v4/letter/j/3d9bf3/32.png) [@jjakucyk](https://boards.straightdope.com/u/jjakucyk)\ **Post date:** [December 20, 2022, 2:08pm UTC](https://boards.straightdope.com/t/exercising-against-the-floor-jacks-supporting-our-house/976755/10 "2022-12-20T14:08:00Z")
> [@Dewey\_Finn](#): > > Lally column [![](https://img.youtube.com/vi/05WhNMT8FWE/hqdefault.jpg "Mr Blandings Lintels") ](https://www.youtube.com/watch?v=05WhNMT8FWE) ---
**Author:** ![Babale](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/babale/32/15666_2.png) [@Babale](https://boards.straightdope.com/u/Babale)\ **Post date:** [December 20, 2022, 2:33pm UTC](https://boards.straightdope.com/t/exercising-against-the-floor-jacks-supporting-our-house/976755/11 "2022-12-20T14:33:19Z")
It’s probably safe to exercise against, but if you ever capture your supernaturally strong arch enemy by removing the source of his strength, don’t tie him to the posts just in case his strength comes back at the last moment as he will definitely collapse the house down on you both.