Need contractor recommendation to find elusive leak

[Joshua Dorkin]

Hey Denver!  

I've been looking for someone to help us find the source of a leak in the house, but we have so far been unsuccessful.  There's water that is somehow damaging the hardwood floor by a back sliding glass door, but we can't figure out the source.

When I've had other contractors check, we've found no moisture in the walls or even in the ceiling of the basement below -- the moisture is only registering on the floor.

There are also no pipes in the area.

My only guess is that this might be coming from some kind of roof leak that is just passing the walls and collecting on the ground in the walls.

At the end of the day, I need someone who can help figure this out and can help us fix the issue.

Got any suggestions?