We did the PVC bed rails for our top bunks......just put a 90 degree elbow on the bottom piece and cut another 20"+ piece of PVC and turn it back under the mattress...the weight of the mattress will hold it plus the weight of the person on the mattress....you don't have to glue these elbows or pieces to your rail...that way you can adjust and turn as necessary.
2014 Jayco White Hawk 30DSQB Summit Edition, Glacier Package
2012 GMC 2500HD Z71 SLT 4WD Crew Cab...DuraMax/Allison....3.73 Rear Axle.
2014 Chevrolet Silverado 2500HD Z71 LTZ 4WD Crew Cab...Vortec 6.0L V8...3.73 Rear Axle..(traded)
2011 Chevrolet Avalanche...5.3L V8...3.42..(traded)