Insulation before adding a heater

[jante76]

Good morning all.

I have a 2.5 car detached garage. pyramid roof? 4 sided roof. The front half has a half sort of ceiling, and the back half on the other car side has the same. It's mostly just for storing things like my patio table and chairs in winter, so it's pretty open. It's not an option to build a ceiling in there. I live in the midwest just outside of Chicago. Mostly use the garage for doing bicycle work.

Anyway, I am going to add a heater, but need to insulate first. I just did the walls on New Years day. I have one vent the roof. and 16 soffit vents.

So my question is regarding baffles. From what I've seen soffit baffles aren't really designed to have the insulation run all the way up the rafters. So if I just install the 23 by 48 baffles the insulation will just stop the airflow as soon as the baffle ends at 48in making them useless? I may be wrong. Probably am.

Do I just install the baffles and run the insulation over them or is there some other way to go about this.

Thanks in advance for any advise!

 

[ddawg16]

I'm a little confused.

It sounds like you want to insulate the roof portion between the roof rafters, is that correct?

Normally, when something like that is done, you also drywall the inside...and when using the baffles, you have a vent at the bottom and the top typically goes into a 'troff' area or straight to an eve vent. Since you have one roof vent, I'm guessing you will make a troff?

You need to give the air coming up the baffles a place to go.

You might want to reconsider the ceiling.....in the winter time, it would do a great job of keeping the heat closer to you in the garage, otherwise, all the heat is going to be up in the attic portion.

BTW....welcome to GJ.....hope you stick around.

 

[jante76]

I attached a few pictures to show what I am looking to do. Just insulate the roof I guess.
I still have a few spots to insulate on the walls, but need to move some shelves. I am going to get some more electrical boxes out there so I will drywall once all that is installed.

Thanks for the welcome!

 

[75gmck25]

Do you have a budget for the job?

One easy (but not that cheap) solution would be to have the roof deck spray foamed, which would also seal off the soffits and the ridge vent. If you have them add fire retardent spray (they actually have a fancier name for it) you don't need to cover it with drywall, so no additional work on the ceiling/roof is required. Then make sure all exterior wall penetrations are sealed, and add insulation and seals to the garage door.

The only caveat could be the moisture trapped in the garage if you use a gas or propane heater.

Bruce

 

[jante76]

No budget really. I got a couple of quotes to run the gas line from the house to the garage, got a quote for drywall. The main hold up is the gas line and the electric at this point. I need a new electrical box in the house and I told the guy that I want some more electricity to the garage and he said it wouldn't be a problem, just need the trench. Apparently which it's too cold to dig, or frozen.

So, I likely won't be getting any heater installed til fall, but I want to get the walls and roof insulated, so that it'll be good to go for next winter, and I have a bit more time on my hands this time of year.

I still need to figure out a storage cabinet and will most likely put a shed out behind the garage to store the bigger items, lawnmower, snowblower and the various yard work tools.

 

[cadunkle]

You have a hip roof. Look up hip roof insulation and cathedral ceiling insulation. Bottom line is you can either spray foam thick enough to not have condensation issues and eliminate all venting, or build some sort of ceiling/attic space and maintain venting from soffits to a vent at or near the peak in that attic space. "Attic" could be very high, but the lower the ceiling the easier it is to heat and be comfortable at ground level.

There was another thread recently about this, some ideas in there and I posted my experience insulating a hip roof as well.
https://www.garagejournal.com/forum/showthread.php?p=8281200#post8281200

 

[ddawg16]

jante....pictures help a lot.

You don't have a whole lot of storage up there.

Have you heard the phrase "You learn by your mistakes"...well, that is why so many of us are so f'ing smart.............

Seeing how you don't have any drywall on the walls yet....Scrap the plan for baffles and insulation on the roof rafters.

Run some 2x6's on 16" OC across the span.

In one spot, install some pull down attic stairs.

Drywall the ceiling and then the walls.

Install insulation in the ceiling

Install 1/2 CDX plywood on top of the ceiling joists. (now you have some decent storage space)

Paint a nice color.

You will be shocked at how much brighter the lighting will be with drywall in there....and the temp a lot easier to control.

My garage used to have the same roof....not a whole lot you can do with it. I would NOT insulate the roof....

 

[jante76]

Thanks for the advise and suggestions @ddawg16 and @cadunkie. I think ill end up doing a ceiling.
I will just have to get a shed out behind the garage, which I planned on doing anyway. I need somewhere to store the patio table during winter amongst other things. That'll free up space in the garage too.

 

[ambenz]

Hey neighbor....I live in the same climate as you.
Curious if you have insulated garage doors?
I have clopay insulated doors on my garage and piped in natural gas from the house, with 1/2 black pipe, when it was built.
I also have a hip roof with 10 foot walls and a 91/2" ceiling and needed to do the same thing...on the cheap!
So I installed Johns Manville AP Foil R-13 Faced Polyisocyanurate Foam Board Insulation 4X8 sheets in the ceiling.
I used car washers and drywall screws to keep it up there and used spray foam on the areas were they join.
I wasn't very concerned with the look....

View media item 84151
I do not have any insulation above the panels but I am sure you could blow in insulation if you wanted a better R value as the panels are pretty rigid.
I made a man door to get up there to store stuff if I want too.
I imagine you could paint the foil backing.
Cost me about $100 for materials and I am using a undersized 30K BTU ventless to keep the garage a comfortable 55F.
Paid for itself in one season!

 

[jante76]

Oh, that's a pretty cool solution. I did get one of those insulation kits from Menards. It is enough to do a 9 x 7 door. I have 2 and got 2 kits. I forget the r value, but it was pretty decent. The door is sealed all around otherwise.

I think the majority of the project will get done in spring time. I'll have to see how things go.