[Jack Houpe]

I had the same problem so I drilled a 5/8" hole through the wood and foam then took a piece of plastic tubing and cut it to the length that it stuck out the bottom 1/2" and used silicon rubber them in place. Looks like crap but works great, I wanted the top of the pipe even with the floor.

On our airstream interstate class B we had a electric dump valve and it worked great, I did away with the solenoid valves and the air dump valve as its just one more place to leak air.

https://www.amazon.com/Valterra-E1003VP-...MATED&th=1