Raising step down living room questions

phil.

I'm looking to raising the floor of our living room to be level w/ the rest of the house. This level of the house is on slab and the living room is 5.5" lower than the rest of the floor (the room is approx 18'x20'). I understand that I have two options: 1) frame in a new floor or 2) pour concrete.

For a DIY, it seems like framing it would be the solution. Okay here is what I'm thinking:
1) remove old carpet and tack strips
2) lay down vapor barrier over existing concrete slab
3) Rip (pressure-treated) 2x6 down to height so that + new subfloor is level w/ the higher floor we're trying to match
4) Install ripped 2x6 16" on center, but I don't understand how or if necessarily these boards will attach to the existing concrete slab?
5)Install some type of insulation between the joists (thinking this will help reduce any sound differences when walking and transitions to the concrete subfloor, any problems w/ this idea?)
6) Install (nail or screw?) sub floor on top of new joists

I'd like to know anyone's thoughts on this method vs concrete and also if you can help address specifically how I will attach the new floor joists to the concrete subfloor.

Thanks for any help or suggestions,
Phil

Ron6519

You don't really need pressure treated wood over the 6mil plastic. The weight of the framing will keep it down, no need to attach it to the floor. I would attach it to the adjoining walls. After the frame is constructed, check for and low spots that might need shimming. You can use starter shingles to slide under any low spots. For attachment I would use construction adhesive and screw down T&G plywood.
You can put the insulation in, I don't know if it will make any difference in the sound. It could help with the cold.
Ron

crecore

definately "glue and screw" T&G flooring. ...actually use construction adhesive. This will be a lot less likely to squeak and will make the whole system work as a whole so if the slab has dips you will be less likely to here a joist flexing and tapping the slab.

Darylh

This level of the house is on slab and the living room is 5.5" lower than the rest of the floor (the room is approx 18'x20').
What is the material between the slab above and the sunkin floor on the sides???

phil.

Mostly concrete. 2 sides of the room are exterior walls of the house and these are actually concrete blocks on the sunken portion (framing for the walls on top of the blocks). One wall is an interior wall and it is just the slab. Where the floor transitions to another room it is a wood board (likely the form board from the slab pour I'm guessing) next to the slab. One normal size door way transition and another long (9-10ft) transition.

Big Bob

Don't forget to remove your base boards. I would remove Drywall also ( just to avoid any future problem if you have water damage.)

Install your ripped to height 2x6 as a ledger board at the perimeter of the room.

Start where this ties to the existing floor. Used a block = to your new sub-floor plus floor ( think finished height down). You might want this ledger board a little shy so you can shim for any ups and downs. This is your only really critical area.

Run a double floor joist 12'+8' (offset your splice) down the middle.
PT always best/ poly & insul ok ( sprinkle boric acid for future critters)

Screw and Liquid-nail deck as advised

PS think about a floor outlet while it's wide open. You will be glad you did.

phil.

Okay on the two walls of the room that are exterior walls there is concrete blocks up to where they framing of the wall starts, how do I secure my first ledger board to the concrete blocks?

Thanks for all the helpful replies thus far, I'm looking forward to getting this project underway.

Big Bob

Tapcons would work great, or if you know how to swing a hammer.... cut nails are the old fashion way, but you need to hit the mortar joints . I would also use liquid nail.

Have fun and don't hit the wrong nail.

Ron6519

If you have a power nailer or can borrow one, that would work. Add construction adhesive to the back and you're good. The tapcons are also a good method, no special tools, though a hammer drill makes it go faster.
Ron