Can someone point me to the right resource?

UptownZoo

Hi all,
What I need right now, more than specific advice, is directions to some clear instructions (clear as mud, huh?). We bought a new house that has a dining room adjacent to a sunken living room. We need to raise the floor of the living room so that it's level with the dining room. Both rooms are on slab concrete and the difference is about 14".

Anyway, I'm just having a hard time finding the directions I need. All my web searches are coming up with directions for raising the floor in a house that's sinking on its foundation. I have a pretty good idea what we need to do, but it'd be nice to have some good instructions for the finer points, ya' know?

johnny331

Are the ceilings at the same level? Or will you have to raise that as well?

UptownZoo

No, the ceilings are the same.

AtlanticWBConst.

Hi,

I am assuming that you have already taken into consideration the ceiling height difference (Loss of height) - were you to change the floor height in the living room. .... you must have ceilings 9' or higher(?)

First off, you would need to determine EXACTLY what the difference in floor heights is between the two rooms, prior to starting any work. Know this at your planning stage.


Example: You could install a vapor barrier (poly), then install 2x4's on the flat around the perimeter of the room. Then install 2x4's on the flat laid out in the pattern of a floor joist system. Again -on the flat, 16" On Center.

Then install a rim-joist set up around the perimeter of the room using 2x12's (11-1/4" width). Next, install 2x12's on the 16" O.C. - sitting on top of the (laid flat) 2x4's. Install these like a normal floor joist set up (deck type layout-except no joist hangers needed). That would give you a height of 12-3/4" (2x4 flat + 2x12 vertical).

At that point, you would have a nice "sleeper-style" floor joist system laid out, with the 2x4's centered underneath the 2x12's (like an upside down "T"). You should also attach those 2 framing members together with long screws or shorter nails, being carefull not to penetrate the Poly Vapor barrier underneath. OR:
If you are concerned with this, you can even use "L" brackets to secure them together instead.

(FWIW - At this point, it's important for you to determine your finished floor height)

Once that is done, install your floor sheathing (3/4") Tongue and Grove CDX or ..... "Advantek" floor sheathing (This is all we use).

Now, you should be at a floor height of: (2x4 on the flat: 1-1/2" + 2x12: 11-1/4" + Floor sheathing: 3/4" ) = 13-1/4".

That means that your sub-floor height would be at 13-1/4" height off the original sunken floor surface.
That gives you 3/4" to work with a finished solid type flooring, and you are at 14" overall height.

Another option is to simply use 2x14's vertical joists - with T&G floor sheathing.

So, you see, you need to know the exact height difference....

The above is just an example. The actual height you need dictates how you will frame/build this.

__________________
- Build Well -

pjpjpjpj

Just a thought - don't forget you will need to raise all the electrical receptacles, switches, etc. There are code requirements for heights, but even if not, you wouldn't want a switch down by your knees and the wall receptacles may end up at floor level. That's going to require a lot of drywall work.

Also, I hope there are no low AC grilles in the room - if so, you will have to raise those as well.

You will also (probably) end up with windows at unusual heights.

Curious why you need to raise the room - if the step(s) is/are the problem, it might be easier to just install ramps instead of steps....

KUIPORNG

floor sunk by 14" that is a lot....how can that be possible... all the wood studs will be broken.. it must be me who don't understand this....

UptownZoo

Thank you all for your replies! I'll try to answer the questions, and then I have a few Qs of my own.

There are two outlets that have to be moved up. We've done that before so no problem. This house has hot water baseboard heat (can be a PITA, I know, but I have a severely asthmatic son, so the improved air quality that this kind of heat can provide was a major deciding factor for us in buying this particular house), and we'll have an expert come in and move the unit in the living room for us. That's not a project I'm prepared to handle, though I will be shadowing whoever we hire to do the job so I can get a feel for the system. The window isn't a problem; it was set to match the one in the family room on the other side of the front of the house, so it'll actually look more normal when we raise the floor. No AC grills; we're in the desert southwest, so just an evap cooler vent in the ceiling.

The steps aren't the problem. We just have a very large family. The dining room and living room are basically just one long room, cut in half and differentiated only by the steps down to the LR and a decorative beam across the ceiling (no worries; the inspector checked that for me yesterday and it is truly decorative, not load-bearing). We need lots of dining room and less living room and with the steps down, there's no way to put in the giant dining table that we need. Also, I just don't really like the way it looks. It seems old-fashioned to me. Plus, we have a number of elderly and/or disabled friends and family and we'd like them to be able to visit us comfortably.

Do you mean in the floor? Or the walls? Just that one section of the house is on a slab; the rest is on a crawl space. The steps are poured concrete, too, but they don't extend quite to the walls. So the wall studs are just longer in that one area. Is that right, or am I just making a massive display or my ignorance here? I love doing home improvement projects, but this is by far the most ambitious thing I've ever done, so I could be completely clueless for all I know! And yes, 14" is a lot. My mom loves it, but I think it looks really weird, literally like a hole.

AtlanticWBConst. - I don't know how to thank you for taking the time to write me such a detailed post! I am so grateful; you really gave me the jumping off place that I need. Yes, I know that I need to take very careful measurements. I don't have them yet because we don't take possession of the house until the 21st of this month, and I can't measure accurately until I rip out the carpet and padding. Egad; all this makes me wish I could just back a cement truck into the house and fill in the stupid hole!

Anyway, thanks so much for the info. We'll have lots of projects to do in the next few months, both preparing the new house to live in, and preparing our old house to sell. I'll definitely be back here again!