In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
Ive got a rental on top floor that i have started to build with a rheem 64 tankless unit under a future stair behind the bath room. its 3/5 vent goes right out a 13" brick exterior wall. directly under floor, below im building my own unit with another bathroom and its own rheem 64 Id like to gang the two flues together and have only one wall penetration but rheem and metal fab are just too stupid to reach or answer questions in any way that instills confidence that some idiot is reading from a script in fact they dont even answer this question and refer you to a paid service. anyway im aware of the issues but also think ive seen this done on large commercial jobs any ideas?