Want to insulate a garage closet

[BillN]

Closet is in an attached single car garage. I'd like to turn it into a veggie starting area so I need to insulate it. Is there an insulated fire resistant panel I can use to simplify the process? It's in a corner and two of the walls as well as the top are 1/2" plywood I'm a geezer and want to do it as simply as possible. Any suggestions? Thanks, Bill

*I wouldn't bother but the eggplant, tomato and pepper varieties we have grown in the past or would like to grow simply aren't available around here anymore. Everyone wants to grow heirlooms which don't do well in our area but are the hot item right now. Rant off.

[mike4244]

Closet is in an attached single car garage. I'd like to turn it into a veggie starting area so I need to insulate it. Is there an insulated fire resistant panel I can use to simplify the process? It's in a corner and two of the walls as well as the top are 1/2" plywood I'm a geezer and want to do it as simply as possible. Any suggestions? Thanks, Bill

*I wouldn't bother but the eggplant, tomato and pepper varieties we have grown in the past or would like to grow simply aren't available around here anymore. Everyone wants to grow heirlooms which don't do well in our area but are the hot item right now. Rant off.

If I understand you correctly , 2 walls are exterior. Are they insulated? 2 other wall yet to be built and need insulation. 1/2" sheet rock is fire resistant. 2x4 walls with fiberglass insulation on the walls yet to be built. I would make a wood floor from 2x4 joists and insulate between joists.
30 lb felt first then joists and plywood floor. Insulate ceiling as well. 
I start seeds in a similar area, I use electric heat mats that raise the temperature 10° warmer than surrounding air. I use 2 heat lamps when temperature is 60° or below. Also have an electric oil filled heater that I only use when garage temperature goes below 20°.
I start tomatoes in late February , peppers, spinach and Swiss chard in middle of March , most other seeds that are started indoors around April 10.
I have two gardens. Small one will have watermelon seeds direct planted. Green pole type beans will be planted on perimeter. Beans grow on chicken wire frames 5'-0" high around perimeter.
The larger garden is 15'-0" x 30'-0" and in a high tunnel. 
mike

[brianwelch]

I think I would start with extruded (pink or blue, not white beadboard) 2" insulation panels on the floor topped with Fire Retardant plywood. For the new interior partition, I believe drywall needs to be at least 5/8" thick to be fire rated, and I would do that on each side of an insulated steel stud frame. Make sure the existing exterior partition is insulated as well.

[BillN]

It's an existing closet, 3/8" plywood structure dating from ~1950. Thanks for the suggestions, I'll think about it and decide if I want to go to that much trouble. When you add up gathering up the sheet rock, installing more studs, etc. that seems like a fair amount of work and everything is a lot more effort when you're 77 years old.

[jamesglenn]

You could use a foil faced insulation to apply over the existing walls, but it is not fire rated. The foil will help prevent ignition and reflect some of the heat back into the space. Why are you wanting to make it fire rated?

You can get insulated panels with either g.w.b. or o.s.b. adhered to it if you desire.

If the walls are sheathed, you could either fill the cavities with blown-in insulation or possibly spray foam. 
TigerFoam makes a fire retardant foam.

Jimmy

[BillN]

A friend of mine suggested going to habitat and seeing if they had any used ceiling panels, mineral fiber. I could put some insulation behind it and tack it up. I'll check that out tomorrow.

[BillN]

A friend of mine suggested going to habitat and seeing if they had any used ceiling panels, mineral fiber. I could put some insulation behind it and tack it up. I'll check that out tomorrow.

I found used mineral fiber ceiling boards at Habitat, the plan is to paint the smooth backside with bright glossy white and put that up possibly with some sort of insulation under it.