You may need to give up on the idea of 'preserving' the floor underneath if you need to create 'flat'. To get flat, you will need to screw down plywood (1/2" or thicker). You will then use that underlayment to attached your engineered hardwood over top (nail/cleat/staple/glue).

If you are thinking of "soft" underpad (like cork) then you STILL need to create flat...which would require sanding/filling before using the cork. To use cork over the existing floor, you would need to float the engineered hardwood. This is one of the only ways to preserve the existing hardwoods, create something as close to 'flat' as possible AND have a new engineered hardwood installed at the same time.

You would FLOAT the 1/4" cork (lay it down...nothing holding it in place other than the wood sitting on top). And then you would FLOAT the hardwood. Again, you would have to have FLAT to begin with. Cork won't fix 'wonky'. And if cork can't fix wonky, nothing else will either.

Is there a reason why you are not refinishing the existing flooring? It is traditionally cheaper.

NO. Absolutely NOT. Either refinish what you have, or rip to something you want.

May Lee , that will void your new floors warranty. Most installers would not take this job.

Thank you for the suggestions. Only my upstairs has the original hardwood floors from the 50s, but I’m building an add’l 2Bed room downstairs (Basement level) and won’t be able to find same hardwood. Really want to have same look both upstairs and downstairs. And because it’s downstairs - engineered hardwood is suggested because of moisture. Hence, the dilemma.

So you’d suggest installing cork on top and/or ripping out hardwood?

It's always best to ask your installer or simply contact the manufacturer of the flooring you'd like. Lots of uninformed pros on the internet...

" If you plan to install over concrete, you must use an engineered product to ensure structural integrity. Solid wood flooring or Engineered flooring may be used over plywood, existing wood floors, or OSB subfloors. Be sure to refer to Shaw's installation guidelines for specifics on subfloor requirements."

https://shawfloors.com/flooring/how-to/hardwood/how-it-s-made/solid-vs-engineered-hardwood

Ok...now this is more like it. You have TWO levels with wood on them. It is totally acceptable to have TWO DIFFERENT wood products/looks/colours on two different levels. The only thing that needs to be "the same" is the stairs. The stairs should match the wood on the MAIN floor of the home (as in the public areas such as the formal entranceway, the living room, dining room, etc). After that, you can do what you want.

As nice as it is to have "the same" wood both up and down, you don't have to. As for matching the existing hardwood, you can get darned close. And don't forget, you can always pick the ENGINEERED hardwood FIRST, and then have a master flooring refinisher MATCH the stain for the upstairs wood when you have it refinished.

Yes...it is that simple.

Adding cork underneath a floating engineered hardwood (not all engineered hardwoods are ALLOWED to be floated...which is probably new to you) is possible. The PROBLEM comes in when you realized you need to trim and rehang ALL of your doors. And then you realize your STAIRS are no longer 'to code'. Now you have to add in another $10K for the stairs (no...I am not kidding...stairs are DEATHLY expensive...and NO ONE wants to deal with them because they become legally responsible for issues should anything happen). So we are all saying do NOT put another wood floor over top of the old unless you have tens of thousands of dollars to spend on the upgrade for EVERYTHING on the upper floor AND the stairs.

I say go ahead and get an engineered hardwood for the basement level and then bring in a high-end NWFA Certifed Sanding/Refinisher to come as close as possible to matching the colour you chose.

Of course stairs are a beast. They are often made of a different wood than the rest of the hardwood floors which means they can take stain differently. But that's another dilemma.

Photos of what you HAVE in your home right now....and photos of what you were THINKING of getting please. This will help us help you.

Thank you so much for all your advice @SJ McCarthy!

Sharing a pic of my stairs upstairs - it's parquet for living room and narrow plank in bedroom

from the 50s.

Sharing picture of engineered wood - white oak. As you can tell, they're both different shades.

This is why I'm thinking of redoing floors upstairs.

I have interior staircase that is carpet right now that I'll need to put engineered wood too.

Let me know your thoughts? And, THANK YOU!!!

@JAN MOYER - so would you recommend that I get the same color of engineered wood for basement too?

I'm not Jan, but I'm guessing you can find something you'll like in between the two: less orange than the parquet; less gray than the engineered oak.

We have a 1940s condo with very thick oak parquet. We had them redone (for the first time) in 1996. They went from very dark and disgusting to much paler and lovely.

Agree you should find a really good floor company and ask what they suggest for the parquet, then look for an engineered product that blends nicely.

You are saying you DON'T like the first floor. So either REFINISH or replace it but not with a gray floor , please. .When I say replace, I mean rip it first.

BTW, Stair to either a basement or a second floor can and probably should have at least a runner. You haven't shown the stair either, But a stair to a basement ? I'd probably paint the stairs Tread black, and risers white, and add a runner in a great pattern.

If you want the look of the french oak everywhere, do it, and do it right. Rip.

Thank you! Now need to figure out if I should rip and replace my 50s floor. I can't decide - must noodle.

Save the original strip flooring. Replace the parquet with matching new unfinished strip flooring and install unfinished matching engineered flooring in the basement. Then refinish and finish old and new to match new interior design. Engineered hardwood is available in unfinished, not just pre-finished. If, you have the budget remove all existing flooring and install your choice of flooring, as others have mentioned.

Fantastic advice, @G & S Floor Service. What is unfinished strip flooring? And, how do I find unfinished matching engineered flooring for basement?

This is not that hard.Unfinished wood is just that. Raw. No stain, no seal, in its natural state. From a flooring pro . You have oak? You get unfinished oak, in strip width. Basement and main floor really have nothing to do with one another. You can't see both at the same time.

The point is................do you hate the main floor? It can either be a match to existing strip/oak floor and lose the parquet, or do the entire house to one floor as you selected for the lower level,

Strip flooring is any flooring width 2 1/4" and smaller. You have 2 1/4" wide flooring. That means you have strip flooring.

Your local flooring supply shop can get you unfinished engineered flooring.

@G & S Floor Service - thank you so much! I'm moving forward with your approach. now need to shop for strip that is unfinished...

Recommend any brands?

And, for finishing unfinished engineered wood and hardwood, what is the process and avg cost for let's say 1200 sq feet?