No Korads actually no I'm not a tightass and I would rather not spit in any ones face even a goofy face. I have to face reality. I'm 72 working 800 miles from home and working alone. I'm taking what ever tools I think I might need in a small car and that doesn't include a 40 foor ladder. The temperture will be in the teens, the roof is a 12-12 pitch made out of slate etc etc etc. I'm doing the job for free for an elderly woman who needs to rent out some space in order to keep her house.I'm not pulling a permit because that would bring on a higher assessment which is the reason she can't afford to live there in the first place. I'm paying for most of the supplies myself out of my social security check. I woud buy the 3/4 if it were necessary but why put in more than necessary. My concern was pressure and flow nothing else. I'm sure you routinley put in 1" copper lines just because they are bigger the hell with the cost right. Hell you probably put in copper drain lines too ...only the best I'm sure and you don't charge a penny more and you never cut corners. I know that side wall vents work I've seen enough of them in my day and I know they are illegal. I'm not sure that it would work in this case and that is the only reason I asked. If it wouldn't work then I wouldn't do it I'm not stupid. I can program a computer in three different languages, repair a transmission, anti lock brakes locate an electrical short in a Lexus faster than you can take a piss, frame a complex roof, build spiral stairs, carve ornate wooden designs, repair electronic equipment, weld ARC,MIG,TIG, blow glass and just about any other damn thing you can think of. So think about me the next time you have someone change your oil or fix your VCR. I've seen jerks like you my whole life. If you don't have something worth while to say then don't say a thing. People are on this site to get information not be insulted by the likes of you.