>how to concrete I have this post that goes right through

>>1204780
Prop structure held by pole
Cut post
Remove post
Clean concrete somewhat
Remove small amount of dirt from hole
Pour coffee can's worth of mixed quickCrete
Smooth while wet
Place post on concrete
Attach new post to old structure

Oops, also let the concrete dry first

Support the weight elsewhere, cut about a half inch off above the concrete, and hammer in a half inch thick welding shim under the pole.
Easy.

Thx for the input guys. Should I use any kind of backer for the cement or just pour it in? Been reading up on it and it seems I should get hydraulic cement as it expands and will plug the hole better. During heavyrains water will rise out of hole but getting weeping tile install so not too worried about hydro pressure going somewhere else after sealing.

>>1205206
You could use a concrete bonder if you want, most of them you brush on to the existing concrete surfaces that will contact new concrete and let it dry so its slightly tacky and then pour in your new concrete. Acts like a glue between the old and new for a better bond.

>>1205214
I see. Should I place any backer at the bottom of the dirt whole? I got some of that insulation foam tube that you put over pipes I can stuff down there. I use it as backer for filling cracks before caulking.

>>1205219
foam doesn't like a good idea - I'd think if anything some gravel - since there is usually gravel put down under a concrete floor.

all that said I bet the "proper" way of doing this is to pull your rotted wood post out and cut away a larger access hole in your concrete floor. dig down a few feet and pour a proper footer with a bracket on top to re-install a new support post (wood kept above the floor level or a steel post)...
Ill do a quick sketch and post it in a few...

File: new post support.jpg (43KB, 724x694px) Image search: [Google]

43KB, 724x694px

>>1205756
diagram.

>>1205756
>>1205769
something very similar to this was done in my (120+ year) old house. I bet at some point my basement floor was just dirt. then later (thin) concrete floor was poured to make it more usable (for storage) then later still the main beam spanning the whole house needed shoring up so three steel columns were set on three concrete footers that were poured through holes cut through the floor and a long steel I-beam placed on top of the three steel poles replaced the original wood beam spanning the whole house. that shit ain't going no where.

>>1205769
taking a 2nd look at your pic - and your comment that the post is currently loose and not really supporting anything. I'd still go with my diagram but you could probably re-use your old post, just cut the rot off the bottom. I had a similar situation with a 2X4 post that was "supporting" part of the basement stairs. the bottom rotted from contact with the cement floor over the decades (long before I woned the house) and I just removed the post and cut the rot end off and added a 2nd 2x4 and a dutch lap joint to replace the post to actual "support" mode. tho I doubt it is really even needed; the stairs are supported in other spots and by the stringers. the floor above is supported by the steel columns and steel beam.

>>1205769
>>1205776
Hey thank you very much for taking the time to draw that, that is pretty much what I imagined it is too. Your issue and mine sound very familiar, the house is from the 50's so the post has probably rotted over time, it's very loose and I figure once I take a sawzall to it I can pull out the rotted wood from the ground leaving a hole. I will then follow your diagram and call it a day. I may replace the post with a 4x4 fence post but the main goal is to fill the whole first.

>>1205769
Do this. A slab isn't really intended to support a point load like this.

>>1205776
>the post is currently loose and not really supporting anything.

This would be the time to check the structure above the post for sag. And jack it up level before putting in a footing and cutting the new post to length. But don't get carried away or too much jacking could crack plaster and jamb doors.

File: basement floor jack.jpg (184KB, 2000x2000px) Image search: [Google]

184KB, 2000x2000px

>>1204780
Use one of these.

/thread

>>1206051
>the main goal is to fill the whole first
diagram anon here; well the 'proper' job isn't just 'filling the hole' - you are making a 'footer' to support the post. this will probably require you to make the hole in the floor left after removing the post a little bigger and also digging down into the dirt below a bit then pouring in the concrete. and don't forget to put something on top of the footer (a post bracket) to anchor the post to before the concrete hardens. will be major pain to drill it in later.
>>1206108
yeah, this will do the job but these are really meant to just be temporary. tho I suspect a lot of people end up leaving them in place long term. problem here is if the post in question is really holding some weight, just slapping another post or a jack like this under it and on the [thin] concrete floor the floor will just crack and sink under the weight.
looking at the OP pic hard to tell if where that post is located is really carrying a load - there is that square column of bricks nearby (assuming that is a chimney base?). that could be tied into the floor structure above and carrying some or most of the load in that area...
BTW a 4x4 fence post should be perfectly fine to use. that is essentially what was there with two 2x4s put together. as other person said, you can jack up the beams above a bit then cut your post and fit it in snug, then lower your beams back down onto the post. that will give it a solid fit.

>>1206108
man, I love Basement Jaxx

(self-sage for stupid comment)

>>1207400
cont.
also to jack up the beams you can use an adjustable column like >>1206108 (the top portion is adjustable via a screw - you need a big wrench and a lot of leverage)
or you can use a 2 or 3 ton automotive floor jack (with a wood beam (could be another 4x4 or two 2x4s put together) cut to fit between the jack and the bottom of the beam). even better is a 'bottle jack' - they lift straight up and usually have even higher 'ton' ratings then automotive floor jack. I've used both. both will work but bottle jack is easier. and as other person said don't lift too much or too far too fast or you risk cracking plaster and throwing door jams out of wack.
you can get a bottle jack for cheap at everyone's favorite; Harbor Freight. I bought an 8 ton bottle jack from there many years ago and its still working fine today.

>>1207404
You need no wrench for those jacks you turn the tpp until it makes contact and there is tension between the floor and what its supporting, grab the fat part and do a couple of jerks. Thats it. There is no spot for a wrecnh

>>1207561
guess it depends on the type/brand. ones I've used had a spot on the screw where a wrench is used to really get a tight fit or actually lift.

Isn't that a bearing wall 12 inches away?

>>1207708
yeah I was wondering what that stack of bricks is - thought maybe the base of a chimney: I have a similar thing in my basement complete with an access door to scoop out ashes yet I do not have a traditional fireplace above - I think it was a chimney that had wood burning cast iron (pot belly) stove(s) hooked into it. but yeah if that is a partition wall then I doubt that wood post is even needed - yank it out, fill the hole in the floor, done. it looks like maybe that was a post to hold up some stairs - seems like stairs back in there above the tires. stairs should have enough support from the stringers so post may not be needed.

>>1207400
Op here, the basement has two of those brick pillars. They are not part of a chimney system but are support columns for the main house beam(?). I'll take some pics if needed. I have a hydraulic jack that I use for my car maybe I'll use that then I'll check the tonnage. Thx for the input so far!

>>1207402

I see what you did there. Well played anon.

>>1204780
>>1205769
>>1205776
Yeah, the main issue is that concrete in basements is always damp because of condensation, so wood in contact eventually rots. So it depends on whether you want it to be done "right" (which would require knowing the code in your county re how deep the footer has to go etc), or whether you want it to prevent your house from settling and be in good shape for 10+ years and that's it.

The quick fix is to jack it up with >>1206108. Houses are surprisingly flexible so 3-6" should be doable with no issues. You CAN use a car/truck/bottle jack but you have to be careful to stack it correctly, the main issue is if it has any angle, it'll slip while you are working on it.
Cut off the bottom 6" or so of the post, then slip in 2-3 solid cinderblocks underneath. A slightly better solution would be a hollow cinderbock under the post (if you can fit it in), and fill it with concrete and set a bracket into it so the wood wont sit on damp concrete and rot in the future. the concrete would also pour into the hole.

Get a spade bit and a drill, you're probably going to have to core out the wood and chisel it out from the inside. When they're set into concrete like that the concrete enters into the pores and cracks for a good grip. Also, wood rot generally needs water AND air, so it'll probably be sound under the surface.
Personally, I'd knock out the wood for a bit under to give you a solid 4-6" slab, and then leave the part in the dirt. Footers are mostly necessary to prevent frost heaving, and the rest of the slab will prevent that.

>>1205769
what's the point of gravel though?

>>1208274
So water doesnt turn the soil soft and settle.. rock allows drainage.

>>1208251
>Get a spade bit and a drill, you're probably going to have to core out the wood and chisel it out from the inside. When they're set into concrete like that the concrete enters into the pores and cracks for a good grip. Also, wood rot generally needs water AND air, so it'll probably be sound under the surface.
>Personally, I'd knock out the wood for a bit under to give you a solid 4-6" slab, and then leave the part in the dirt. Footers are mostly necessary to prevent frost heaving, and the rest of the slab will prevent that.
whaaaaa?
above you said use a bracket so wood not in contact with concrete. here you are saying to drill and chisel the wood for *better* contact?
footer size and depth differ depending on local code. but looks like this is in the center of a basement, don't think frost will be a problem here. basement floor is most likely already more then 4 feet below the ground level and your in the center of a somewhat climate controlled space. if it were near an outer wall then that'd be another story. question is; if what's above really needs support (considering there seems to be a brick wall nearby) and if so how much?
if you don't use a post bracket, another idea to keep wood on concrete contact from rotting is to put a chunk of something that is rot resistant on the base of your 4x4 post. that kind of "plastic" wood would work or maybe a piece of 'green' wood (which would last longer in contact with concrete then 'regular' wood). I did this with wood shelving I built in my basement that sits on a concrete floor.

>>1209696
>your
you're