Floor leveling advice needed

[craignlisa]

I am renovating a kitchen and bathroom in 1 apartment on a 40 year old quadraplex. The kitchen floor is not level to the tune of 1-1/2" over 6 feet over a 6 x 6 foot area. This area joins the hallway which is also low. How can I level the kitchen floor? The floor construction is 2 x 12 joists, covered with 1 x 6 boards running diagonally with 1/2" gaps. There are 3/8" plywood sheets covering all this. Rather than using a liquid compound that would have to fill very thick, can I "rip" 2 x's to give a tapered 0" to 1-1/2" over 6 feet? Make about 8 of them then space them evenly over the affected area on the floor then cover the entire kitchen with 3/4" plywood. Where it joins the hallway I'll use a transition moulding because of the "step" created (I'm only working on the kitchen not the hallway). Does this seem too labor intensive? Will I have creaky floors? Is this to code?

[HayZee518]

Seems like a good plan. Just a question but when the 2X12's were installed were they put in with the "cup" side up or down? 2X12's considering their length have a crown if you sight along one edge. Usually this crown is installed upwards so that as weight is applied in the middle of the span it tends to reinforce the spring back of the board not add to it.

[craignlisa]

Thanks for the quick response.

As to your question I do not know the answer. This isn't my building and I do not have access to the joists (except for the view thru the flooring) and cannot see the bow.
One other thing, once I have leveled the floor and it has its new 3/4 ply surface, is there anything else I should do to prepare the floor before I put on the "finish surface" (I'm installing a floating floor here).

Thanks

[floorman]

should'nt have to do anything else to the floor once you have it flat.For floating floors the tolerance is 1/8 inch in 10 feet so it needs to be pretty flat.Just buy the underlayment thqat goes with the floor you buy and you should be O.K.[8D]

Floorman
floorlayers union local 1310

[Commando]

I have an almost identical situation to yours and would like to know how you plan on "ripping" your leveling solution accurately? 0" to 1.5" or more seems pretty tough to get right. It's not like feathering drywall compound. Ideas are welcome.
Thanks,[8]
Commando

[mrcaptainbob]

Just went through this with our bathroom. Although I sistered up the floor joists, it was not possible to square it away for various other reasons. What I did was to set up a laser level and measured five locations from the light to each joist. (each joist being about 7 1/2 feet long.) I sketched out a 'chart' of the bath and noted the dimensions at each 'location'. I also inserted a dimension that would be the mean between each, giving a total of 9 points on each joist. The 91 dimensions ranged from 1/8" to 1 7/16". I cut the 91 spacers to match and laid them out according to the chart. The spacers were then glued to the joists. The next day I laid down the 3/4 ply and did a check...maybe a 1/32 in two feet! So I screwed it down and continued on. The end spacing between the spacers wsa less than 9 inches. I felt comfy with that, since the joists spacing is 16". A second layer of 3/4 made what was already a solid floor like a rock.

[craignlisa]

To Commando:
I built a solid (non-floating) dock on our lake front. It is in the shape of an "L". Basically it is 8 feet wide throughout and the "straight" span is 25' long. At this point it turns 90 degrees to the left and spans 15 more feet. The point where it turns I've had the 5/4 x 6 ripped at my local lumber yard. All the boards were ripped equally 0 to 6" taper. By spacing them all equally, I've created a fan design. There are around 20 boards that accomplish this stylish look. I drew it up in a 3D software (I design with this) and gave the dimensions to the saw man. For a minimal charge (20 bucks for the whole lot) he ripped them all with no apparent problems keeping the tolerances. The regular flooring boards are all rounded edges so after these one were ripped I used my router to re-create the rounded edge on the cut side. Turned out fine.

Anyhow, just to update you all on my kitchen floor job:
I started noticing rotten wood joists in some areas of this floor and decided to remove all the sub-flooring. I replaced the 1 rotten joist and doubled 2 x 6's to the remainder of the entire floor joists (16' long floor x 17 joists spaced 12"). I used PL Premium adhesive along with deck screws to attach them together. When I set out straight edges over the floor I found the lowest points (where the washer/dryer leaked over the years) were 2-1/4" below the highest points (along the foundation walls). Now I have a perfectly level and very solid flooring joist surface on which to lay 3/4 or 1" ply. Plumbing is next then the floor. So it seems if I won't be using the taper idea anyhow.

Thanks to all

Here's a view of the dock

http://www.homerepairforum.com/images/uploads/2005-4-1_Image06_(2)_w550.jpg

http://www.homerepairforum.com/images/uploads/2005-4-1_0407070009_(2)_w550.JPG

[mrcaptainbob]

Great job on the dock! Thanks for sharing those. As for the water damaged floor, that was part of the problem here, as well. The other parts were that some joists were forage for the local carpenter ants, and the rest of the problem was due to age and gravity taking it's toll. Did as you described by sistering up the salvageable ones, replacing the ones totally gone. But the originals kept their bow regardless of the jackposts. That's when I used the laser level and shims. Glad yours turned out good.