Wall mounted toilet help

[Jourdan]

Hi all,

So I'm redoing a bathroom for a customer in their basement. Their 3" abs drain is a mess and not set to the correct heights. The original toilet in the basement seems to drain fine. I believe theyve never had an issue because it is a raised ranch and their plumbing upstairs has enough force to move waste to the city sewer. I only need to raise the plumbing another two inches where the toilet will be going and I did not see a reason to use a grinder pump for that short of a distance. I talked the customer into a wall mounted toilet, so my question now is do I need to use a closet carrier to mount the toilet? or would it be ok if I frame the wall in a way that I could stub 4 bolts through with a closet flange and mount the toilet that way? Also I've read that if you're going to mix abs and PVC in your drain system all connections where the two different pipes meet should be connected by a metal banded fernco fitting. Is this true?

 

[frodo]

use a 2x12 inbetween studs with a hole drilled for the pipe
then. drill the 2x12 with a 1/2'' wood bit
install galvinized 3/8'' alll thread rod
DOUBLE NUTTED on both sides of the wood

 

[Jourdan]

Awesome, thanks. I figured that would be enough to support the weight of the toilet and someone sitting on it. Also had another question. Does the toilet need a separate vent from what's there? I believe the venting is at the upper end of the vertical 3" draining in the first picture, making it a wet vent. The 3" drain to the left of the vertical in the first pic goes to the toilet, the 1 1/2 drains left to right in the second pic are the bathroom sink, kitchen sink and washer drains. Will it be ok to hook the toilet up since the old one flushes fine?