New engineered wood floor over old uneven hardwood floor?

Question

100 year old house has uneven hardwood floors on second floor. Initially I wanted to sand and refinish these, but they are not in good shape and are squeaking. Then I decided to put brand new hardwood or engineered (my favorite) wood on top of it, hoping to obtain a better look and less squeaking and noise downstairs (with the help of a foam underlayment).

I am afraid that because the floors are uneven, the new engineered wood will not stay in place correctly.

I wanted to level the floors, but the self-leveling cement would add too much weight on this old house.

Is there a light, foam-like self leveling compound?

Also, what's the way to lay the engineered wood in this situation, glue it or lay it floating? If glueing it, what about the underlayment? Do I have to glue that layer first and the glue the engineered wood on it?

Answer 1

If the floor squeaks now, it'll probably squeak somewhat even after you put the new flooring over the top, so Job #1 is to stop the squeaks. Here are some techniques, depending on what type of floor you have:

http://www.thisoldhouse.com/toh/article/...

Deciding to refinish the existing floors or go over them is a judgement call. I'd fix the squeaks first, then have an experienced floor finisher over to take a look. He may be able to make them look so good you'd wonder why you ever wanted to cover them up!  

I installed an engineered wood floor in my house (basement rec room) and love it. However, in your case make sure you account for the change in floor thickness--it will affect baseboard trim, door swings, and transitions to the flooring of adjacent rooms. Most any problem can be solved but some solutions end up being more trouble than they're worth.

If you opt for engineered, I'd suggest the floating floor approach. Your existing wood floor moves with changes in temperature and humidity, and gluing something to an unstable surface isn't always successful. With the floating system the two floors will move independently. Here's a step-by-step explanation on how to lay a floating floor:

http://www.thisoldhouse.com/toh/how-to/i...

As for leveling the floors, yes, there are lightweight gypsum-based self-leveling underlayments, but check manufacturer's recommendations so see if they're suitable for use over hardwood. If you have to use so much material that weight is a concern, maybe the stuff isn't the right solution for your problem. If floors are significantly out of level, it's usually better to correct whatever structural problem led to an unlevel floor if you can.  

Answer 2

How far are the floors out of level? It may take some patience but sanding out the high spots may enable you to install the floor without alot of 'other' solutions. At this time just renailing all the squeaky spots may be done and a floating floor installed. No messy glues or nails and a easy install. If installing engineered wood it would be glued to your original floor acting as an underlayment. Of course all the original flooring has to be structurally sound and installed correctly for this to work.

Answer 3

Your engineered wood floor is going to have to wait until you do a few things to the existing floor.

#1. Since your hardwood floors are not in good shape, I would drill pilot holes and install screws to try to eliminate the squeaks.

#2. If you have uneven place more than 1/4" high or low, you need to do some prep work. I would cut strips of 1/4" underlayment and carefully use a 2' level or straight edge to find the low spots. Glue down the appropriate width underlayment strip to fill in the dips.

#3. Now run your new engineered floor perpendicular to the old floor and use the floating method vs. glue or nail down. You have to be a little more particular especially if the end of a pc. is in the dip. Have some small cedar shims handy for this problem.

Wherever you stop make a transition strip to bevel down from one floor level to the other.

Answer 4

Before you do anything, I would fix the squeaking because this won't go away.  Check out This Old House website...they have a lot of good tips.