Just make sure there is no wires, pipes or tanks before drilling. If you look around the belly, you will see other gaps that will need to be secured or filled to keep the critters out. As long as you have a open can of spray foam, go inside the trailer and use the rest on pipes and wires that go through the floor. The factory likes to make a 3" hole for a 1/2" wire ect...
2011 Coachman Freedom Express 295RLDS- Sold
2015 F-250 FX4 SUPER DUTY 6.2L Gas 4WD SuperCab XL 3.73 rear / 158" WB / 8' bed. Factory anti-sway and brake controller