Ideas for leveling this floor.

I'm waiting on the window system to get here for my 3-season Patio. In the mean time, I'm finishing up a lot of details and trim work, including putting down a section of the kitchen flooring that had to be taken up, temporarily.
https://photos.app.goo.gl/Bi8qjLdnUQTjYwj69
The joists underneath this section of floor were very rotted which helped cause a pretty good dip in the floor. Because we were pouring a new concrete pad for the patio, I was able to cut out most of the rotted joists, shore everything up, and replace that section with the concrete pad. For many reasons, it was not feasible or even a good idea lift the joists up to take the dip out of the floor. But I didn't want the new pad to dip with the old floor, so I had the pad poured level and figured I'd shim the sub-floor to meet the pad.
That's where I'm at. There's a 3/4" difference in height from the left side, 12ft. over to the right side and it's only about 16" wide. In my mind I have 2 options...
1- Lay plywood sections down in different thicknesses, in increments from 1/8, 1/4, 3/8, 1/2, 5/8, and 3/4, forming a ramp to level it out. Sand the seems between sections and let the flooring adhesive fill any small gaps. But this means gluing these sections of plywood down to the concrete.
2- Pour a self-leveling mortar bed. This seems to make the most sense to me, however, I've never worked with it before. Also, on the left side, it's going to be paper thin where it meets the existing pad which is already even with the old sub-floor. Won't that area be prone to cracking and breaking up? Would I need some sort of mesh fabric to reinforce it?
Let me know what you think.
--

-MIKE-

"Playing is not something I do at night, it's my function in life"
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On 10/28/18 1:09 PM, -MIKE- wrote:

Actually, I forgot that I'm putting in a cabinet on the left side of the doors, here. The difference in height is 3/8, where the cabinet would end, so I could pour the mortar to that point, 3/8" deep, using a curb of some sort. So it wouldn't have to taper all the way down to paper thin.
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-MIKE-

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On Sunday, October 28, 2018 at 2:09:55 PM UTC-4, -MIKE- wrote:

Assuming I have my math right..
How about resawing wide tapered shims from 0" to .625", gluing them side by side to the back of 1/8" plywood to create that "ramp" you mentioned? A few Tapcons to hold it in place and Bob's your uncle.
.625 + .125 = .75
With shims laid side by side, your ramp would be one solid piece.
The shims don't have to be 12' long, cut my math in half and make them 6' long, butted end-to-end.
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On 10/28/18 5:58 PM, DerbyDad03 wrote:

Yeah, good ideas. I'll consider that. Thanks. Part of me wants to do the mortar thing just to put another skill on the list, you know?
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-MIKE-

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On Sunday, October 28, 2018 at 9:17:16 PM UTC-4, -MIKE- wrote:

I know what you mean, but is a kitchen the best place to learn that type of skill?
Learning to make drawers and doors is one thing. You simply toss or fix your errors. Screwing up mortar in a kitchen can get pretty messy.
Mortar isn't very forgiving. Is SWMBO? ;-)
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"-MIKE-" wrote in message

I see this scenario as a trip hazard if you try to fix it in 16 inches... As such, I'd be inclined to remove the flooring and sub-floor for about 4 feet and then place solid wood tapped shims on top of the existing joists to blend the two levels. Then reinstall the sub-floor and finish flooring. Spread over 4 feet the trip hazard would be pretty well eliminated.
Regarding the shims, I'd attach them to the joists with glue and finish nails to avoid splitting them. After the glue dries nail or screw the sub-floor down and go from there.
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On 10/28/18 8:32 PM, John Grossbohlin wrote:

Did you look at the pictures? There's a 12ft by 16in portion next to a wall that contains a French door. The trip hazard is what I'm trying to avoid and will with whatever technique I choose.
If we were doing the kitchen remodel along with this patio addition, I would likely have had the whole finished floor and probably the sub-floor ripped up and replaced by now. :-)
But it's silly to do that for this little stripe of flooring.
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"-MIKE-" wrote in message

From your description and the photos it looked to me like the concrete was level across the width and along the French door. This while the wooden floor dips and gets lower and lower than the concrete as you move left to right. The transition from the wood to the concrete is where you have the problem.
I'd think that if you tried to blend the two in the strip of wood sub-floor shown you'd have a rather abrupt angle at the 3/4" variance end. That is why I suggested removing a bit more of the flooring and the sub-flooring the blend over a wider area by putting tapered shims on the joists (under the sub-floor).
I'd think you have the same rather abrupt angle using floor leveling compound if you only worked in the sub-floor area shown.
Also, if the resulting "sub-floor" (wood and concrete) do not smoothly flow from one to the other there is some risk of the laminate flooring cracking (a real problem with the fiber/particle board laminates from what I've seen in a couple older home do-it-yourself projects).
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On 10/29/18 12:55 AM, John Grossbohlin wrote:

Sort of. The wood floor dips from right to left, is higher than the concrete on the right, and on the same plane at the left. But yeah, that's what's happening.

There may be something you can't see in the pics. I added another photo in the album to better show what's happening at that transition. https://photos.app.goo.gl/8kX2emmUY3rLfTpi8
There are 2 layers of plywood subfloor, which is very common from this time period. They put down 5/8", frame the house, then lay down 1/2" on top. When I pulled up the old finished flooring, I also pulled up the 1/2" layer of plywood underneath it. The horizontal plane of that little step is my horizontal guide for the new section to meet it.
Whatever I do to shim the new section to the old section will sort of follow this little step and it will continue the plane of the old floor the remaining 18" until it hits the wall and door threshold. That's all I'm doing... continuing the flat plane of the floor to meet the wall.

That's one reason I'm considering the leveling compound as it will fill everything and be totally smooth on top. However, in the time it's taken me to type all of these posts, I could probably have been done with the wood route and had the old flooring put down. :-)
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-MIKE-

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"-MIKE-" wrote in message

Overall, in the photo it looks pretty much like I thought it did conceptually... an ugly transition!
Me personally, I'd remove the sub-flooring down to the joists and use tapered shims to make the joists transition as outlined previously. Then put down the subflooring. If there is room perhaps use 3/4" ply for stiffness. With the shimming done well a bit of sanding might be all you need to smooth the transition. This assuming laminate padding/paper is used between the sub-floor and finish floor to take care of minor variance (e.g., 1/32" or less),

Yup... analysis paralysis is a common problem!
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On Sunday, October 28, 2018 at 9:32:37 PM UTC-4, John Grossbohlin wrote:

...snip...
You must be imagining a different problem than I am.
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wrote:

Floor leveling compound? It's made for this sort of thing.
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On 10/28/18 9:06 PM, snipped-for-privacy@notreal.com wrote:

Yeah, that's what I'm thinking.
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-MIKE-

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Looking at the picture, it looks like this is sort of a bay window and the unlevel part lays the lenght of the bay. Since this is an outside door, have you thought of putting tile in the low spot. To gain the depth, pull the existing floor boards out in the area. and lay a new subfloor between the joist. then pour the concrete, and put tile on that.
You could extend the tile a little into the room and make the tile area a little wider.
You could even tile the room using a similar method.
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On 10/29/18 6:53 AM, Keith Nuttle wrote:

Thank you, but all those decisions and choices were all made months ago before starting on the patio. More pics of its construction can be seen, here... https://photos.app.goo.gl/nHLDkWJwdvgXBYS26
This was the best option for this project and now the only thing that needs to be done to tie it all together, is having the two planes of both surfaces meet together.
That's the advice I'm seeking.
--

-MIKE-

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On Sun, 28 Oct 2018 13:09:50 -0500, -MIKE- wrote:
<snippage>

There's a product called LevelQuik, a self-levelling underlayment, which should do just what you want. Also, the bit on the left side will be sandwiched between your finished floor and the old subfloor, so I wouldn't worry too much about any cracks being noticed on the final floor.
Cheers, Colin
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On 10/28/18 10:27 PM, Colin Campbell wrote:

Thanks. That is one of the products I've been seeing in my research. As for that bit on the left side... there will be a cabinet over that section, anyway, so I may not even bother with that part. I'll probably just start at the right edge of the cabinet and go from there. Cabinets are easy to shim.
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-MIKE-

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