Hello, this is my first time here.

I'm looking for advice on pouring a new concrete floor in my existing dirt floor basement. It's an older house (1885) with plenty of water percolating through. It has French drains and a sump pump that works quite well. This is just a little bit of background. I do have a couple of simple and specific questions that I'm leading up to. I moved in a couple years ago. The house has a decent stone foundation topped with brick. The house was supported in the middle areas by wooden collumns sitting on stones or blocks or maybe just dirt, I'm not sure. I assume that several of them have been changed out. Each time one rotted away a slightly shorter one was put in its place. I've given up on the idea of jacking the house up (though I welcome comments). I just want to support it in its sagged state and put in a new floor. I have put jacks in between the existing and missing collumns and have lifted slightly. I have 17 jacks in place supporting most of the inner parts of the house. So I want to put in lolly collumns where the wooden or missing collumns were.

My questions are: How should I do the footings for the new collumns? Should I dig them out and pour them to the level of the future floor and then pour the floor around them afterwards? Or should I pour them lower, install the lolly collumns and then pour the floor over the footings and around the lolly collumns?

My plan is to start with the missing collumns where I can work easily. I'm leaning toward the first idea though I was thinking that it would be best to have the floor completely sealed over with cement. Maybe that's just the downside of starting with dirt floor in an existing house. I'm also wondering where I can get some additional information on the whole process. Maybe there's a good book on the subject or maybe there's a section of this website that I haven't found yet.

Thanks in advance.

LR

 

Why are you considering the cement floor? I am guessing you won't be using it as basement living space with that many columns? So, what to you hope to acheive with the concrete?
Later
Duneslider

 

The basement will have 10 collumns, I think, when it's done. I have more temporary jacks than I had collumns. As I recall, there were 5 collumns per beam which divide the basement into three sections of probably 450 square feet each. It will be a low ceiling but good for a workshop, storage and maybe a pool room.

 

If your house is sagging now would be the time to fix that. If you are going to be pulling the supports to put new ones in you might as well level the house while you're at it. If the sag isn't bad you might not want to worry about it. I am not an expert at the leveling area but I would say it is something to be looked into, especially since you all ready have jacks.
You will want to check your local building code for the size and depth of the concrete footings and piers. They will be able to tell you what code is.
You could pour the floor first but I think it would be easier to do the footings and piers and then pour the floor up to them. You will want to make sure all the footings have the same height so the floor can be poured right up to them leaving a level floor. Really either way will work just fine.

Sounds like a fun undertaking
Bryan

 

Yes, a fun undertaking and I think I will feel like an undertaker by the end of it. Or I'll need one. I have tried jacking the house up but it looked me square in the eye and said "nope". I think I was able to budge it, but it really doesn't seem to want to move anywhere. I do have a hydraulic jack now that I will probably try in conjunction with the screw jacks but if it still doesn't want to, I'll probably leave it. It's not like the house is sagging and just waiting for a little help to spring back up. It's like the whole house has taken on the new sagged form. And to make things worse, I think panelling jobs and installation of cabinets and things to the unsquare walls helps it maintain its new form. I'm not all that against having a house that has that kind of character anyway. I was wondering just yesterday if there was somewhere I could get old wavy glass to match the other original wavy panes of glass in the house. I like that it looks as old as it is.

 

You can find the old wavy glass. I know I have seen it around but can't say I remember where. A little research and you will beable to find it.
Have fun with the project
Bryan

 

I finally figured out that my house originally had only four collumns holding up the innards. I think back in 1885 people just didn't have so much stuff in their houses. I would like to put a lally collumn in between all of them to end up with a total of 10. I spent a good while today at the lie-berry looking through countless books trying to find information on what footings for collumns should be like. Can anyone tell me?

I have a dirt floor and I want to start with just the footings for the collumns. Do I need gravel? Do I need a vapor barrier? How big and how deep should they be? Where would YOU go to get this information? I tried the home store's books too.

Also I used a cheesy little laser level today to try and get an idea of the amount of sag I have in my house and I think that it's actually about 4" of drop over 20 feet at the worst. It is quite noticeable. I'm thinking I will try jacking it some. I tried a 12 ton hydraulic jack a little bit today in conjunction with the screw jacks and it seems like I could get it to move maybe. I screwed the jack to the end of a 2x6 beam and put a couple handles on the beam to carry it around and position it. It worked out really well.