Bought a new to me trailer and pulled the mats. More mats under the mats and those mats are glued to the aluminum floor. Of course they. Are cracking and allowing water to puddle underneath so up it must come. But how? What will cut through the rubber and what will break the adhesive that is still holding in places?

Maybe call the service department of the trailer manufactuer?  Since it is an aluminum floor, I wonder if there is a solution that gets up glue and can still be used and not compromise the aluminum?  

The trailer manufactuer would know that.  

 Good luck.  

Why would somebody glue the floor mats down to the floor, that is just crazy. I always pull my mats to make sure I get all the cra* out of the trailer and check for pitting of the floor. 

Good luck on getting those mats up, just make sure the product you use wont harm the aluminum.

what brand?

The floor was applied after market. Husband got the rubber up, so we are only left with tar-like circles of adhesive. At least we can see the floor and no more water will pool up under the floor.