Options for unlevel basement floor

[Deke]

I have this fantasy of finishing half of my basement (the other half remains my shop), but among many challenges is that the 95 year old cement floor is far from level. Head room is also an issue so any attempt to lay strips or pour on top to make it level are not good options. So, there is probably no prayer of tile or laminate flooring. Digging up the floor and pouring a new one... I don't think so. Are there any other options? The idea isn't to make this a home theater or living space, but something nicer than a basement and add in a full bath (that I will level the floor for). For example, maybe a workout room, storage + craft type work area for my wife. Clean with nice walls and a floor that could be presentable.

Also, what is the best way to figure out exactly how out of level it is - finding and marking the high points, the low points and everything in between. Is some kind of laser gadget the best thing here?

 

[tbellemare]

A laser level and pole come to mind for determining level.

You could stain/finish the concrete. It doesn't take any vertical space. It might be possible to do a little grinding and then stain/finish.

Tom

 

[WarnerConstCo.]

If it is that old, I bet it is at the most 2" thick.

 

[Deke]

Warner, I wish! They were a little skimpy on this basement. Also, get this. My neighbors have the same exact house, two of them, and both their basements are a foot deeper (foot higher ceiling!!!). They say these basements were dug by hand (in 1922) and with all the rocks around here, they just went as far as they could and stopped. I have no idea if that is true, but some times I wish a I had a time machine so I could have done a little job site supervision.

I think I may be avoiding what really needs to happen - dig it out and have a new one poured. I can do all the nasty demo work, save some money and build up some muscle. However, not a top priority, just a dream, you know, of having my man cave thing (shop and a nice place to hang out). Lord knows I need it, because my wife has taken over everything else!

 

[Rob Z]

Deke, as Tom suggested, the use of a laser is the best method. 

What we do when we are prepping a floor for either  a mud bed or SLC (self leveling cement) is to find the highest spot (with the laser ) and mark it "0" (with chalk, paint, a Sharpie, whatever works). 

We then mark various points around the room with negative readings ( in inches) that correspond to the distance below the elevation of the "0" mark.  With this method, we map out the floor and can then estimate how much material we need and also will know how thick or thin the material will be when placed. 

We just finished a kitchen in an old house in Washington DC.  I set the "0" mark in one corner, near the stove.  Our negative readings ranged from ~ -1/2" to as much as -2 5/8".  That was one scary floor, and we only improved it about half-way, based on what the customer wanted.

 

[Notorious T.O.D.]

Sell house, buy better house....  Hire movers.

Might make the lady of the house happier also.

Best,
Todd

 

[mouppe]

I like the look of epoxy for basement floors. It would also work well in your workshop.

Richard.

 

[jimbo51]

I had a complete basement waterproofing done in a row house which included replacing the entire floor. The basement floor was at least three inches out of level with the worst high spot being at the base of the stairs which made for unsuitable headroom (

 

[SteveC]

Before digging out the floor. Be wary of the foundation kicking in, as the floor is holding it back.

 

[Holzhacker]

Having done this job more times than I can remember, here are a few thoughts.
- Dig out the floor, stop trying to rationalize some other nonsense.
- Warner is probably right, that cement is most likely 2" thick more or less. Old basement floors like that are very common here. It could be thicker but the odds are low. It's easy to break out and dig. It's messy, sloppy work but good work for a bunch of teenage boys. Have a teenage son with friends? Buy a few demo hammers and shovels. When we used to do these jobs when I was a teenager, my old man would let me know and I'd get some buddies together. Worked out great, we'd get paid a lot more than anywhere else; it was a lot cheaper for the old man than paying real men.
- Around here $7 a square foot is fairly average for repour by a contractor
- Do you have floor drains? Check the floor drain to see how far down it goes prior to the trap. This will give you an indication of how low you can dig without having to deal with sewer lines. Around here about a foot is possible 90+% of the time. More than a foot is sometimes possible. If the sewer rides high then plumbing costs could be an issue.
- You may also need to deal with footings depending on how low you go. If digging out X inches brings you to the perimeter footing, you may need to pour an additional curb along side the footing and the new floor to stabilize conditions
- Are there current ground water issues that should be considered in relation to digging up the floor
- You need 7' finished height for compliant occupancy space
- Yes various epoxy coatings can work and would be the thinnest solution. As long as the floor isn't moving anymore an epoxy coating should be fine.
- Think about how long you will stay in the house, how the house will be perceived with or without the improvement during a sale as compared to other local houses, what will it cost and can you get the money back at resale.
Hope that helps, Markus

 

[LostInTheWood]

Having done this job more times than I can remember, here are a few thoughts.
- Dig out the floor, stop trying to rationalize some other nonsense.
- Warner is probably right, that cement is most likely 2" thick more or less. Old basement floors like that are very common here. It could be thicker but the odds are low. It's easy to break out and dig. It's messy, sloppy work but good work for a bunch of teenage boys. Have a teenage son with friends? Buy a few demo hammers and shovels. When we used to do these jobs when I was a teenager, my old man would let me know and I'd get some buddies together. Worked out great, we'd get paid a lot more than anywhere else; it was a lot cheaper for the old man than paying real men.
- Around here $7 a square foot is fairly average for repour by a contractor
- Do you have floor drains? Check the floor drain to see how far down it goes prior to the trap. This will give you an indication of how low you can dig without having to deal with sewer lines. Around here about a foot is possible 90+% of the time. More than a foot is sometimes possible. If the sewer rides high then plumbing costs could be an issue.
- You may also need to deal with footings depending on how low you go. If digging out X inches brings you to the perimeter footing, you may need to pour an additional curb along side the footing and the new floor to stabilize conditions
- Are there current ground water issues that should be considered in relation to digging up the floor
- You need 7' finished height for compliant occupancy space
- Yes various epoxy coatings can work and would be the thinnest solution. As long as the floor isn't moving anymore an epoxy coating should be fine.
- Think about how long you will stay in the house, how the house will be perceived with or without the improvement during a sale as compared to other local houses, what will it cost and can you get the money back at resale.
Hope that helps, Markus

Yep I totally agree with all of this...plus... you may also be required to put in some kind of egress depending on how your local codes view the use of your room.  Also, about the footings,  if you go down deep enough and have to pour a curb or step the existing footing, then remember to do it in sections and not entire walls at a time.  Otherwise your footings can shift or kick out if you undermine them too much.

 

[Deke]

Thanks everyone. As suspected, no easy fix. There was some part of me dreaming one of you would have some miracle solution, "Just spray on Leveler X90 and in two hours your floors will be as good as new."

I do like my house and can live with a basement that is, well, a basement. I would like to clean up the floor a bit and can probably do a bit of improving in cracks and appearance (though not leveling) without digging it all up. A better investment for more living space would be converting our very large front porch into a four season room. Others on the block have done this and it is a big difference.