DIY Home Improvement Forum banner
1 - 4 of 4 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter · #1 ·
Hello,

First - please don't tell me I need to hire a qualified HVAC person. I have been trying for almost three months so here I am doing it myself. I am working on renovating a condominium that was destroyed by a leaking roof. Everything is down to the studs and completely rebuilding it. My Mechanical permit says I have to have kitchen exhaust of 100 cfm and brings in outside fresh air. There was original piping in the unit but it got destroyed when the crew had to take out everything. I am going to be installing a vented microwave so I am working on the duct work now.

I am installing 7" rigid vent pipe with a 90 degree elbow at the top to match the other unit's piping and goes directly to the roof. Keep in mind, it's an older commercial building so it is not secured by a roof boot, it just goes up and then there is a screen that allows the air in and out. I have several questions.

Question 1 - Does the damper have to be in-between the elbow and the pipe up towards the top or does it need to be in-between the exhaust boot and the pipe? Does it matter? My thinking is if it is at the top, it keeps the cool air from making the pipe cold and less condensation. However, I can also see how putting it towards to bottom would be beneficial.

Question 2- because I can't put the microwave in right now and I am doing my rough-in inspection; how do I properly secure the piping going up to the roof until later? It is completely vertical. I have looked and I have found nothing.

Question 3 - Do I have to have it secure for my rough-in inspection and then remove it to insulate and drywall or can I provide drawings and show them during my rough-in inspection.

Any help is appreciated.
 

·
Naildriver
Joined
·
14,478 Posts
This is a DIY site. Why would we tell you to hire someone?? Having read your post, there may be ways of doing it, but it would really help us to see what you are seeing. Post a few pictures so it is clearer to us. Thanks.
 

·
Registered
Joined
·
11,331 Posts
Post some pictures of what the situation looks like. What do you mean that there's no roof boot?

We don't care if you want to DIY it, but most condo corps do. I'm surprised they are allowing you to. I'm guessing insurance isn't paying for this?
 

·
Registered
Joined
·
2 Posts
Discussion Starter · #4 ·
Hello,

First - please don't tell me I need to hire a qualified HVAC person. I have been trying for almost three months so here I am doing it myself. I am working on renovating a condominium that was destroyed by a leaking roof. Everything is down to the studs and completely rebuilding it. My Mechanical permit says I have to have kitchen exhaust of 100 cfm and brings in outside fresh air. There was original piping in the unit but it got destroyed when the crew had to take out everything. I am going to be installing a vented microwave so I am working on the duct work now.

I am installing 7" rigid vent pipe with a 90 degree elbow at the top to match the other unit's piping and goes directly to the roof. Keep in mind, it's an older commercial building so it is not secured by a roof boot, it just goes up and then there is a screen that allows the air in and out. I have several questions.

Question 1 - Does the damper have to be in-between the elbow and the pipe up towards the top or does it need to be in-between the exhaust boot and the pipe? Does it matter? My thinking is if it is at the top, it keeps the cool air from making the pipe cold and less condensation. However, I can also see how putting it towards to bottom would be beneficial.

Question 2- because I can't put the microwave in right now and I am doing my rough-in inspection; how do I properly secure the piping going up to the roof until later? It is completely vertical. I have looked and I have found nothing.

Question 3 - Do I have to have it secure for my rough-in inspection and then remove it to insulate and drywall or can I provide drawings and show them during my rough-in inspection.

Any help is appreciated.
Well, I passed my mechanical inspection so I guess I no longer need an answer. But for learning purposes to those out there if you run into the same thing:

For Question 1: I found out the damper can be anywhere, at the top or down by the microwave hood boot. That is where I chose to put mine.

Question 2: Here is what I did: I hung the vertical duct with Masterflow perforated metal hanger strapping (you can get it at Home Depot or Lowes for around $18 - $19). I double looped it around the vent and strapped it to the ceiling joists on each side of it. The piping is straight up and it was vented out of an already existing roof vent. I then showed the inspector the remaining part of the piping/venting that would go on the microwave that has an external exhaust fan and how everything would be put together.

Question 3: I did need to have it hanging to show the inspector, I can take it down to do the ceiling and drywall but the sheet rockers need to know where it will be so they can punch that out. I will have a 7" clamp up by then to keep it secure.
 
1 - 4 of 4 Posts
Top