Basement floor humidity issues

[SmokeyDP]

I know its not a garage, but hopefully there is enough floor know-how here to help me out...

My basement is currently partially finished. The walls are painted with drylock and there is a french drain installed under the slab. When I moved in the floor was old tiles that were sealed over with a thin layer self leveler (I am 99% it's Ardex. I installed VCT tiles over it and never sealed them right away due to my own error.

Fast forward 3 years and the tiles look really dirty even after a buffing (I would need to use something more abrasive). The corners of a bunch are started to bend up due to crystallized moisture building up under them. I noticed that if we have a lot of rain the basement feels a bit humid unless I run the dehumidifier. On top of that the recent hurricane gave me an inch of water due to a sump pump failure in the french drain and insurance cut me a check to replace the floor. The walls remain dry and I did several moisture tests by taping paper to areas.

I want to rip up the VCT, seal the floor with something that rolls down, then put another floor down. Ideally I want to go with a resilient vinyl, putting down an underlayment first that will block moisture and help keep the floor a little warmer. This will all be DIY.

Any suggestions on what I should roll down to seal the floor? Suggestions for the underlayment?

Here's what the basement looked like a few years back:

 

[SmokeyDP]

Pictures after I got the 1" of water:

 

[buddyboy]

is the floor insulated?

if not I would insulate it to keep it warmer and avoid your warm moist basement air from condensing on that cold floor.

same with your walls, that dry lock is sealing in all the moist air. (as well as sealing out ground water.)

you need to create thermal breaks to avoid cold surfaces to keep water "off", not seal to keep water "out"

 

[SmokeyDP]

is the floor insulated?

if not I would insulate it to keep it warmer and avoid your warm moist basement air from condensing on that cold floor.

same with your walls, that dry lock is sealing in all the moist air. (as well as sealing out ground water.)

you need to create thermal breaks to avoid cold surfaces to keep water "off", not seal to keep water "out"

It's not. It's a house built in the 40's and all but the top 1.5' of basement block is below grade.

The floor us usually pretty cold so that would explain moisture collecting on it. But it seems that the moisture would be coming from under the tiles if it's lifting up the corners?

The floor is easy to insulate, but only 25% of the walls are visible. The rest are behind a 2x4 frame that sticks 1" away from the wall and is uninsulated. I know because I can peak behind it in two spots with a flashlight. They appear to be drylocked too.

 

[Bad Idea]

Smokey,
You might want to look into a moisture supression coating. There are versions out there from Ardex, Koster, Mappei and others. The trick is finding one that is compatible with a good vinyl adhesive. Some (like Ardex) require you to put a layer of cementitious self leveler on top of the moisture suppression and under the vinyl. That adds time and cost to your project - plus you already have leveled your floor.

With a moisture suppression coating, you have to prep the floor, then you roll on the coating. When that is cured, you can apply your glue and vinyl. Just be sure to follow the guidelines from the manufacturer.

 

[SmokeyDP]

Thanks for the help guys.

After speaking with 2 flooring people and doing more research right now I am thinking this padded underlayment because it has a built in moisture barrier and is antimicrobial. Perhaps I can rip up the VCT and roll it on top, but then should I still apply a moisture suppression coating? I guess the question is if the moisture is coming from under the slab or from the floor just being cold.
http://www.lumberliquidators.com/catalog/product.jsp?productId=2011

Also, from what I read about the resilient flooring it's pretty much waterproof and pretty durable. It's also floating and clicks together so I don't have to worry about gluing it down.
http://www.lumberliquidators.com/catalog/product.jsp?productId=18980