The installation guide is available online. Do you know how to use google?

not looking for installation, but more so the prep work on wood subfloor

Smooth flat and even. If he is putting down fibre board (perfectly acceptable under a click together floor - no problems there...no matter it is a kitchen) then the nasty looking plywood just need most of the big stuff dealt with.

The fibre board goes over top of the "fix" and that should be good enough. CoreTec just needs clean, hard, dry, flat and even. How he gets it there isn't an issue. Just so long as he gets it to the point where the INSTALLATION instructions says it is "good enough".

He's doing fine. The fibre board will fix the old "rough" plywood. I wouldn't worry too much about the texture of the plywood. It will be covered by the board.

How level or even? when I check after he patched it is about quarter inch off level, isn't that too much to be off?

Installation instructions should detail how "level or even" is acceptable for the product.

if my floor ends up being acceptable, the new floor will still be 5/16" higher than the meeting next floor. Unless he rips out the old plywood.

would it be ok to lay 1/4" underlayment plywood on top of the existing plywood?

and if so, it would then make my kitchen floor 1/2" higher than meeting next floor? is this too high for transitional flooring?

If you are going to DIY and can’t understand what goes into the steps to do it, you have no business DIYing.

If you're going to hire a contractor that doesn’t research the product’s requirements and explain them to you, and how he is going to accomplish them, then you hired the wrong contractor.

In either scenario, the manufacturer will tell you what is acceptable. You have downloaded the installation instruction no, correct?

Yes DL it and it seems like the contractor isn't following them. So I hired floor company who puts in these floors to give estimate. My plan is if they say he's ok and would do same as he's doing, I'll let him finish. If they say they would install differently, I'm going to Not let him install floor.

One of the great things about Coretec is that you do not have to have a a smooth as glass surface to install it. Yes, level the floor but there is no need to fill every small imperfection in the subfloor. The center core of Coretec does not allow telegraphing, you will not notice any imperfection in the subfloor. I have installed many jobs where Coretec was installed over tile with grout joints up to 1/4". Floor was level, product was installed atop, no issues. No telegraphing of grout joints. If Coretec is being installed next to tile, a T molding is required between the 2 surfaces. The T mold will hide any height difference between the 2 surfaces.

Rigid sheathing over the patch should do just fine. The height difference in the two floors isn't something you can help. If you feel that it is worth the effort and the price, you can ask him to stop and REMOVE the top layer of subfloor. Then ask him to REPLACE IT with NEW plywood.

This will NOT change the roller-coaster waviness of the surface. That is inherent in the house. It will simply give you smooth "new" while keeping the two floor heights as close to even as possible.

If the height variation upsets you, then you have two options: choose sheet material like sheet vinyl or sheet linoleum or rip out and rebuild the entire kitchen floor and *possibly the entire main level.

My suspicion is the KITCHEN floor was raised to meet/match the other flooring. If that is the case, it is possible to remove the current plywood and then drop in slightly THINNER plywood.

Again....this all hangs on the question as to whether or not the kitchen subfloor was raised to meet the other flooring. You are not allowed to go "too thin" with a subfloor. Most industry standards require (depending on where you live and how old the house is) TWO layers of subfloor that equal or exceed 3/4" total thickness.

Sigh. It might be possible to drop the kitchen subfloor a snick. But the amount of money and effort it will take could be a deal breaker. It should have/would have been talked about BEFORE he started patching. And I mean WAAAAAAAY before he started patching. Like several WEEKS before he stepped on site. This would have been discussed because you would have CHOSEN your floor and discovered the difference and would have raised the possibility at the time.

It's not too late...but then again you don't want to see his face after you tell him to rip out his work and start again...with new plywood, etc.

so far thanks for everyone's input, it helps.

i know about the T thresholds, but i thought that was for 2 nearly same floor levels. Will T thresholds work for 1/2" differences in two floors?

Also is there some way to install one stair nose threshold that is in the kitchen to basement. I know you shouldn't nail a threshold to LVT. But I can't find one?

could I? have the LVT go slightly under the stair nose, and then put a piece of plywood under the rest of the threshold. This way i can nail/screw the threshold, but it would be nailed/screwed to playwood? would this work?

Fire your contractor. That means you. Fire yourself. You don’t have the knowledge base to attempt this. And the thin veil of “the contractor” is getting old. No one would be dealing with some idjut who couldn’t do the job correctly and made the homeowner research the problems. At least, no one reasonable would. They’d long since have booted them.

If you shop for the cheapest price for work, you are going to be cursed to find it. And everything that goes with it.

The Reducer is the option for 1/4" or more "drop". A T-moulding, even an uneven T-moulding can only handle 1/8" or so. A 1/4" is a bit too much for an uneven T-moulding. You will need a reducer. CoreTec MIGHT make one....they may not. Since you are the purchasing agent, you will have to find out how/where you can purchase an Reducer.

If you are as high as 1/2" difference you will want a substantial sized reducer with a gentle slope. A PROFESSIONAL flooring installer will know this. A handy-man with limited English skills will not.

Good luck. Go ahead and look on the USFloors website to see if you can find matching reducers and stair nosings for your pattern. Measure the size of the stairs. Measure the size of length of the transition. Order the products with 10% waste or more.

Coretec makes all coordinating molding pieces to match their products exactly. Stair nosing should be around 6' so you'll only need 1 piece.

thank you all....When I hired my contractor he said he had put in LVT floors before, and knew what he was doing. I didn't have experience in ever hiring anyone before for a floor, let alone a LVT floor. He did nearly all the work in my kitchen first, and it was very good. But when it came to the floor, he just did not seem to understand how LVT floors need to be prepped. It's all about the prep work. My gut instinct was warning me something was wrong. i ended up taking the job away from the original general contractor. I went with a company who just install floors, and guaranteed the work. I felt totally comfortable in how they wanted to prep my subfloor & install it. I am very happy I made that executive decision to take the job away from the 1st guy. My first guy was very good at all his previous work in my house, I just wish people would be honest about their limits. But thanks again, all your comment helped me come to this very good ending.

Glad it all worked out. You made the right decisions. :-)

Whew! Bullet dodged! Floor prep done. Floor looks great. Homeowner happy! Our job is done here ;-) So glad we could help!