Title says it all really - in the interests of saving a few mm on a very tight bathroom, is there any reason I can't strap 40mm waste pipe (say abs or pvc) direct to a plastered wall with nothing between? I would strap it down with a rubber or plastic strap band screwed into the wall.
I know clips are available but with the standoff they add another 10mm+ which means I'm at 53mm from the wall, so have to move up to 75mm studwork from 50mm :( It's also going to be tight behind appliances in the kitchen so I'm keen to know if there is a reason I can't strap direct to the wall surface.
Thanks in advance.