Insulating attic floor over garage

[Bobandpamlemay]

I have two attics in my home. One big one over the house and a small one over the garage.

The one over the garage is entered through a door in my daughter's room. The wall between the attic and her room is insulated, but the floor is not. The home inspector said the wall could use a little more insulation, but didn't say a word about the floor needing any.

I was wondering if I insulated the attic floor, would it help my daughter's room stay cooler in the summer and warmer in the winter. The door to the attic is just wood and is not insulated, and I really don't see how it could be insulated.

Could I end up harming anything by putting down insulation? There is no fixed floor to this attic, just laid down sheets of plywood. Underneath that is the sheetrock to the attic ceiling.

 

[Bobandpamlemay]

I have two attics in my home. One big one over the house and a small one over the garage.

The one over the garage is entered through a door in my daughter's room. The wall between the attic and her room is insulated, but the floor is not. The home inspector said the wall could use a little more insulation, but didn't say a word about the floor needing any.

I was wondering if I insulated the attic floor, would it help my daughter's room stay cooler in the summer and warmer in the winter. The door to the attic is just wood and is not insulated, and I really don't see how it could be insulated.

Could I end up harming anything by putting down insulation? There is no fixed floor to this attic, just laid down sheets of plywood. Underneath that is the sheetrock to the attic ceiling. epoxy flooring cape coral

Thanks for any replies.

 

[gun-driver]

Not unless the roof rafters in the attic are insulated (cathedral ceiling like)
You would probably be better off adding insulation to the wall (R-13 min, R-19 best) and get a fiberglass insulated door

 

[volcano buster]

I have a 3 car garage, 2 bays are 20' wide and has an insulated divider wall to the 3rd bay. The 3rd bay is my "shop" bay and the ceiling is insulated. I have minimal heat for winter and a window A/C unit for the real hot days in the summer. The main garage bay does not have any insulation in the ceiling. When it gets hot outside the heat in the attic is unbearable and the heat permeates the ceiling and makes the garage uncomfortably warm compared to the insulated 3rd bay.

I would insulate what you can.

 

[gun-driver]

Buster in your case yes it helps but in his case the attic is next to his daughters room. The attic air space is at the mercy of conditions(hot in summer/cold in winter) which effects the wall/door of the bedroom.
If he insulates the roof of the attic that would help the attic airspace which effects the bedroom wall.
If he insulates the attic floor/ceiling of the garage it will help the garage air space but not the airspace of attic above or the wall of the bedroom.
Best would be to insulate both floor and roof.
This is assuming her bedroom floor is above the conditioned air of the house, if it’s above the garage (non-heated or cooled) then insulating the floor of the bedroom itself would help. Hope this makes sense?

 

[meathooker]

Any wall/floor/ceiling that comes in contact with an unconditioned space needs to be properly insulated. It will make the space much more comfortable, let’s your HVAC system work properly, and pay for itself over time.

 

[gun-driver]

Any wall/floor/ceiling that comes in contact with an unconditioned space needs to be properly insulated. It will make the space much more comfortable, let’s your HVAC system work properly, and pay for itself over time.

Agreed if it’s living space.
If he doesn’t care about the temp in the garage below the mentioned small attic, it’s not cost effective to insulate the ceiling of it. Insulating the garage ceiling will do nothing for the upstairs bedroom that is next to the attic space.

 

[Bobandpamlemay]

@volcano buster thank you so much for your suggestion