Floating Floor over a Sloped Subfloor

Q: I am flooring on the second floor over wood and different types of tiles (some at different heights by the way). One of my rooms also has a gradual 1 and 1/2 inch slope (which is quite noticeable). I was told to put down flooring in the same way that the floor slopes. Is that correct or will I possibly have a problem. I do not want my new floor to crack or not look right. Do I need any other underlayment besides the cork? I appreciate any other feedback you may give me that I haven’t touched upon. Thank you,
Jeff
A: Jeff and I have spoken a bit on this and based on his information, the slope he mentions occurs over about 6ft of flooring in one room of the home.
First off, I would not install without fixing the slope in your floor. As my friend Gene D. ,who works on commercial contract jobs here for iFLOOR.com, always says “I want my plumping to run downhill, but my floors to be flat.”
For leveling, if the subfloor is plywood or OSB you can use any self leveling compound such as Raeco. If you are going to install over finished lumber (such as a pre-existing hardwood floor) you will want to shim the floor up until it is level. To do the leveling, you will want to use chalk lines to line out the area where the slope occurs, then do your leveling work. If you use a self leveler, make sure you give it plenty of time to cure before installing.
Jeff mentioned he was told he could install the floor using 6mm cork underlayment and then running the floor with the slope. Although I wasn’t sure whether this meant lengthwise or widthwise for running with the slope, this could be done, but I personally would want the subfloor flat regardless of the type of floor to be installed.
With a floating floor, if the locks are engaged at angles, rather than being flat, you can run into issues where you will see gaps and the mechanisms themselves can go under excessive stress which can ruin them and cause the floor to fail. Jeff did mention he was a bit worried about adding weight to the sloped area of his floor, which is why he wants to avoid leveling the floor, but again I will stress that I would personally advise to level the subfloor before installing a new floor.
In regards to tools, I would suggest looking one of our installation kits. For floating floors this should cover everything you need beyond a good miter or similar table saw to do your cuts.