# Raising floor 5.5", leveling for floating, potential probs?



## phil. (Aug 27, 2007)

Okay, the house is all on slab, we have a 5.5" sunken/step down living room, step up to hallway and dining room. We want to raise the floor to the be level w/ the rest of the slab and then lay either engr'd wood or laminate (all on grade, not a basement situation). I am planning on framing out the sunken part w/ ripped 2x material + 3/4" subfloor to bring to appropriate height.

My worry is getting all the area's flat so that the install of flooring goes smoothly. Ideally the slab is within 1/8" flat per 6ft :no: , but I haven't actually ripped all the carpet out yet to be able to check. I know that'll be the only way to know for sure how much leveling is going to be required, but I'd like to research/learn a little more before I fully dive into this project (prepare for the worst, hope for the best). 

So let's assuming I rip up the carpet and find that the sunken living room and the dining room slabs aren't flat. Would it be best to level upper slabs first and then frame out the sunken portion to be level? Is building up the sunken portion to be flat enough to transition to the hallway and dining room (dining opening ~ 10ft to sunken portion) and having it be flat within 1/8" per 6ft (tolerance by one flooring option I'm considering) going to be near impossible?

Thanks guys/gals.


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## JazMan (Feb 17, 2007)

Hi Phil,

I think you need 5.5 inches of cement not wood. Once that is done you can address the flatness of the entire floor.

Jaz


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## phil. (Aug 27, 2007)

JazMan said:


> Hi Phil,
> I think you need 5.5 inches of cement not wood. Once that is done you can address the flatness of the entire floor.
> Jaz


Can you explain more why cement would be the preferred option over framing it out w/ wood? I've got 3 quotes so far, 1 wood was $1950, and the 2 cements were $2,450 and $3,400. I've priced out framing it myself and it should be ~$600 for materials, obviously price is my driving factor at this point, but if it's an obvious mistake I would like to know. Thanks.


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## JazMan (Feb 17, 2007)

Poring cement if the best way to make the floor flat and solid. You will not do that with wood.....solid I mean. You're going to have bounce, if not right away, after a season or two as the wood distorts. Then you would have a transition from wood to concrete, that is not good. It's bad enough having a cold joint of 2 concrete surfaces. 

In addition to all that as you mentioned you may have to do some leveling to get a flat plane over the entire area. Having you types of flooring types will only make for more work. Why not do it right and save $$$ on something else if that was your priority.

Jaz


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## phil. (Aug 27, 2007)

JazMan, thanks for the responses. I do agree that concrete would be more solid and easier to get a flat plane between all areas, but do you think that if I'm already planning on having a floating floor if the bounce and transitions would be as big of an issue? Basically I'm wondering if you are thinking of the flooring situation as glue down, but if you considered it as floating if you would think "hm...yeah framing it might work okay". 

If I wasn't already planning on doing it myself for $600, I would for sure go w/ concrete at $2450 versus framing at $1950. I assume concrete (5.5 yards or so) would not be a DIY or at least not a first time working w/ concrete DIY project.

Thanks again.


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## JazMan (Feb 17, 2007)

WEll.....you'll have to get the finished floor very flat, as you already know. I think you said is has to be flat within 1/8" in 6 ft. of the required plane? That could get pretty tricky since you know the slab will not be flat. If you just lay joists on the slab it's going to bounce and move when you walk on it. It may even trap moisture wicking up from the slab unless you are at the top of a sandy hill.

If you go ahead, the only flooring options will be floating laminate or carpet. (if the laminate people say it's OK with a certain isolation membrane or padding they make for that). Both poor choices, but yes they are cheap. Carpeting for obvious reasons. Laminates just look cheap and sound awful. Have you ever lived on one? Neither add any value to your home. 

Jaz


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## cniggeler (Apr 11, 2011)

*Same thought process for garage remodel?*

Hi,

This job seems similar to what we'd like to do. We want to convert our garage into living area. It's 20' wide and has a concrete slab like the rest of the house. There are two issues with this slab:
1. It slopes 3 inches over 18 feet.
2. There is a 3.5" step-up at the end of the garage attached to the house. This raised area is 41" wide (making the total length of the garage about 21 feet).

I was thinking that a wood frame would work well for three reasons:
1. It will allow for thermal barrier between the slab and the subfloor, although pouring new concrete could make radiant heat a possibility.
2. It will cost less than concrete.
3. That's a lot of additional concrete, so I'm concerned about settling and cracks.

Phil, did you ever do this job, and if so how did you proceed and what were the results? 

Jaz, are you saying that no combination of joist spacing and subfloor thickness will suffice to avoid sagging/bouncing, or maybe that it's just a headache that can be easily avoided by the application of a few extra $$$?

Thanks!


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## Bud Cline (Mar 12, 2006)

Pour concrete.


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## Gary in WA (Mar 11, 2009)

There are a few ways to do this. First, do you need additional parking as required in CA? Second, have you check locally with your B.D. for guide lines or requirements for a garage conversion?

Gary


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