How much insulation?

[wildman]

I have a 24'X30' garage. At this point it has zero insulation. I am going to be using electric heat to keep it heated. It has 8' ceilings 1 window, two 7'X8' doors & 1 man door. At this point the type of electric heat is unknown.

I am going to use two 4 bulb x 8' light fixture down the center of the garage.
Then to help with ceiling space I am going to use recessed lights above the work areas. What do I install first when it comes to the recessed lights the cans or the insulation? What R factor should I use? I was thinking R30?

Then what about the walls? I was thinking R13-18?

I need to finish the wiring and have some questions about that too.

 

[Gary S]

R13 should be adequate for the walls. R30 is probably adequate for the ceiling too. With those levels, most of your heat loss will be the windows and the 7x8 doors. Work at making the doors and windows more efficient if you feel you need more.

 

[Falcon67]

Insulate last after everything is installed and the wires are all run. Be sure your can lights are contact rated (or whatever the proper term is).

 

[wildman]

Working on finishing the wiring but man does it take longer than I thought it would. I need to add one more wall and that will be done. Then thermostat wiring.

The cans have to be IC rated (insulation contact).

Thanks

Now my next question would be what type of insulation? Matted I think is what it is called? Use that in the celing? All I have is rafters right now.
And on the walls? The type that doesn't have paper backing on it? How do you hold any of this insulation in place? The matted you staple right? But what about the other kind? And does it go in front of the wiring or behind it in the walls?

 

[Falcon67]

I used kraft faced roll insulation, stapled to the studs with the kraft (vapor barrier) facing the inside. You can then cover the insualtion with your wall covering. For wiring/pipe/whatever that intrudes into the insulation space, you can make cuts in the insulation so it lays over and around the item. Cut it to fit tight around any plug and switch boxes.