Installing laminate flooring over roughed concrete

Hi guys,
I've just spent a day and a half chipping away thinset from a prior tile installation. Unfortunately there are some minor divets in places, and I've uncovered some scary cracks (second floor condo). So now, I've got two questions;

Can I install the laminate over the rough surface without worry (using cork underlayment).

And should I be very concerned about these cracks? I'd hate to just cover them up again without taking any necessary action. There are no cracks in the walls, and they are not following any clear lines (random/jagged).

Thanks!
-Jason

What material is the cracked floor on the second story? How many stories does this building have?

JimR

For laminate, as long as there are no high spots remaining from the old thinset, you'll be fine with the underlayment you propose. As for the cracks, they will not affect the laminate unless the whole building falls.

What material is the cracked floor on the second story?

I'll bet we all already know the answer to that question!

Let me guess. Gypcrete?

Ouch. My bad for not reading the heading twice before posting.

JimR

Wow, that was a lot of replies. There are/were some high spots from the thinset which we've taken down with everything from hand scrapers, chisels, 4inch blades and a belt sander. It's _fairly_ smooth, but there are some divets and some areas where the thinset was so stubborn that it took patches of concrete with it. I was just concerned that there would be problems with it making noise, or not setting properly. And as for the cracks, I was worried that they may be indicative of a much bigger problem. The cracks span a fairly long distance and are wide enough that you might be able to slide a credit card in in places.

Oh and sorry, yes it's on the second floor.

If it were just a concrete floor that has divots wouldn't a self-leveling cement product (like QuickCrete has) work well? Pour on the floor either in the spots to fill or over the whole floor.

But cracks on a second story is something I would have the condo people look at. Or maybe a structual engineer. If this is the start of something bigger then it would be better to know sooner rather than later.

JimR

Jason, as mentioned, you are ok for laminate flooring as it is. You may want to fill those divots with Mapei's Planipatch compound but I would be overly concerned. More than likely your floor is gypcrete----a soft type of cement that tends to crack and break off like tectonic plates. Install the underlayment, be it foam or you mentioned cork. Install your laminate. Enjoy the fruits of your labour.

You guys are awesome.

I did a mock layout with the underlayment and boards and the divots don't seem to be a problem.

I've taken pictures of the cracks for the condo association and have gone ahead with the laminate installation. I only have the weekend free to knock the project out and figured if there was a problem, I could pull up the laminate somewhat easily. I noted the locations of the cracks. I also found another crack on the patio that I can show if they need to see it.

Thanks for all of your help,
-Jason

Sorry. To the Jason Smith who posted this. I was just wondering? Is this the Jason "Smitty" Smith that got out of the army around April of 2002? If not. Sorry to bother! Have a great day!