gas garage heater questions

[bigbrad123]

In the process if installing a gas garage heater (Mr. Heater Big Maxx 50,000 BTU). Trying to save a few bucks by doing some of the work myself and a friend helping. Just a couple quick questions:

1. Is there code as to how tall my stack needs to be out the roof of my garage?
2. Do I need to install a firestopper on the garage ceiling sheetrock where my vertical stack goes out?
3. Since the pipe is 3" around, do I need to cut the hole in the sheetrock a lot bigger so there isn't direct contact with it?
3. Is there code as to insulation touching the vent in the attic?

Thanks for the info.

 

[Hookin8easy]

The fire stop is to keep the 1” clearance to combustible material, or vent fast it is often referred to as it helps hold the pipe vertical and support, insulation in the attic is fine to make contact as long as it isn’t a kraft facing, vent height needs to be 3’ higher than anything else within a 10’ perimeter of the pipe. All of the above are assuming you are using b vent(double wall). Also note that if you are going to leave the heater on all winter don’t set the temp lower than 45 degrees or you could rust out the heat exchanger over time.


you can put the fire stop/vent fast on the attic side of the Sheetrock, it is a little more aesthetically appealing that way, just have the 1” clearance around the b vent on garage side then

 

[wfginsptr]

All these questions should be covered in the install manual.

Also, a permit may required to install.

 

[bigbrad123]

The fire stop is to keep the 1” clearance to combustible material, or vent fast it is often referred to as it helps hold the pipe vertical and support, insulation in the attic is fine to make contact as long as it isn’t a kraft facing, vent height needs to be 3’ higher than anything else within a 10’ perimeter of the pipe. All of the above are assuming you are using b vent(double wall). Also note that if you are going to leave the heater on all winter don’t set the temp lower than 45 degrees or you could rust out the heat exchanger over time.


you can put the fire stop/vent fast on the attic side of the Sheetrock, it is a little more aesthetically appealing that way, just have the 1” clearance around the b vent on garage side then

Ok. I did find the answer on the vent out the roof on the height. Looked it up again in the instructions and found how to measure it. Yes, I am using b vent (double wall). Doesn't mention anything in the directions about using fire stop so wasn't sure. Not using kraft faced insulation (it's blow in), so wasn't sure of the requirements on direct contact on the vent.

 

[dodgeguy]

I put the same heater in my garage if you haven't bought the stack and the roof piece I have that and some stack left as I went out the wall on mine. Sell it cheap.

 

[ORCUS DEMENS]

You stated the insulation is blown in. If it is the cellulosic type you should hold it back at east one inch from class B pipe. If it is fibreglass blown in you should be good to go.

 

[all4eyes]

I put mine out the wall, figured ,less chance of leaks and less to mess with.

 

[johnr]

When the mistake might burn down my home, I call my friend Blaine, that does this for a living. Best off using a pro sometimes

 

[BrokenBackJack]

Guessing might be some guys that do this for a living working for a contractor that would do it as a side job. Ask around, more people you ask better chance of finding someone. Fully understand trying to save money but the risk involved could be deadly.

 

[bigbrad123]

don't worry fellas, having a pro install the gas and another electrician friend install the electric. I'm simply hanging the unit and installing the venting. I've figured most stuff out through lots of research and asking questions on various forums.

 

[eyexer]

go out the wall. far less possibilities for issues later.

 

[Watchyourownbobber]

go out the wall. far less possibilities for issues later.

Can a guy use type b out the wall?? I've seen a few things that suggest class 3(I think it's called such) is needed for wall venting. This accurate?

 

[Hookin8easy]

If the unit has a sidewall kit that is the way to go, if it’s acceptable to b vent or class 3 keep in mind that it has to be 2’ past anything in the area, which translates to 2’ past the roof line which looks real nice:::

if you go up and it’s done properly they don’t leak, sealant under the storm collar, blackjack the shit out of the flashing along the edges underneath, underneath the shingles to the flashing and the nail heads. It’s just how it’s done

 

[johnr]

Maybe a corn pellet stove and a case of cheap whiskey are the answer

 

[eyexer]

has to be double wall to go out the wall. you don't have to go out past the overhang if it's below the soffit by a certain amount. It will say in the installation instructions what those dimensions are. I have both my shop and garage units vented horizontally and neither go out past the overhang. They give off very low temps. And if you have metal soffit I wouldn't worry about it anyway. If it was summer and you wanted to go out the roof I'd say go for it. Not this time of year.

 

[Kurtr]

I am going out the side but was told to go past the soffit and up not for heat reasons but so the moisture does not go right up and in and absorb into the insulation. I am having buddies that do it help so i wont burn the place down. 26x36 how many btus should i go? 10' ceiling

 

[bigbrad123]

go out the wall. far less possibilities for issues later.

Too late. Already cut out the roof and have most of it installed. Got the flashing all blackjacked. A few minor adjustments to the stack and I'm done with installing the unit and stack. I have most of it figured out. Once all of that is done, then I'll have the professionals do the gas and electrical install.

 

[Hookin8easy]

I am going out the side but was told to go past the soffit and up not for heat reasons but so the moisture does not go right up and in and absorb into the insulation. I am having buddies that do it help so i wont burn the place down. 26x36 how many btus should i go? 10' ceiling

Id say 60,000 if your leaving unit on during winter, if your just warming when you need it 80,000. Less cycling=more efficient, it won’t run non stop either if that what your thinking. I have 1200 sq ft with 11’ ceiling and is perfect but garage doors play into that as well, insulated and facing east is what I have. Usually side wall venting slopes down and out so condensation ends up out of the vent and doesn’t rust out the vent or heat exchanger

also mine is newer construction with good blow in attic 2x6 walls and house blocking the west side of garage

 

[Bfishn]

Not to hijack this thread, but has anybody ever had condensation dripping from vent pipe into garage? The condensation seems to be in between the double wall vent pipe and comes down and drips off where it makes the 90 degree turn into the heater. I never had this happen until i got my roof re-shingled last year and they replaced the hail damaged vent cap.

 

[Kurtr]

I just built the garage and house three years ago with 2x6 walls and insulation is good there and ceiling. I was looking at the side venting kits and they are as much as the heaters. I will be leaving it on just to keep it about 40 which it does most of the time the last two years with out heat