even if there are straps underneath you can still have issues.
This is the fresh water tank getting some sun because they only put tape on the straps and expected that to work.
fresh water tank
straps for the tank with just tape on it. All the rest of the tanks had bolts
Scott-2013 F350 with a lot of tires.
2013 40' 4-slider stoneridge 5th wheel coming in at 15,400; 2015 Lincoln MKC
Previous Truck 2008 F250 6.4 with lots of upgrades and a suspension upgrade from Torklift International StableLoads