Room over garage draft and insulating

Hi all,

I recently purchased a home built in the 1920's, the main house is all plaster and in generally good shape and feels well insulated. The attached (but inaccessible from inside) garage at some point had a room placed over it, so it does not have an attic space and the room below is the garage (which I don't think it's insulated, but the ceiling of the garage is covered with cement board along with the walls.

The room over the garage is 17x17 with the ceiling being 6 ft from the floor at the edges and about 8 foot in the center. The room itself has about a 4 inch slope (i presume from the org. garage) so entering the room to the back has a 4inch drop total. Walls are drywall with carpet floor. The door to the room is off one of the bedrooms and that bedroom has a inside window and door (which i presume at one time led to a deck)

The issue I am encountering is that this room is much more susceptible to tempature than the rest of the house, meaning in the summer it can be a good 10-15 degrees hotter, and the same in the winter (especially at night). I currently use this room as an entrainment room with my TV and gaming center (due to it's nice size and shape).

I had just found out that there was a rather breezy draft coming from the baseboards, mostly due to the 4 inch slope leading to larger gaps between the bottom of the drywall and the floor, these were covered up with teh baseboard but when i pulled them away you could see around a 3-4 inch gap between the baseboard floor and outside wall (which has a layer of fiberglass insulation). I purchased a brick of the blown in cellulose insulation, and hand packed the baseboard area as tight as i could to cut down on that draft, which it did, but the room is still quite cool. There are 10 windows (not including the inside one) all oriented on one end of the room (5 per side) These are brand new 2x pane windows, so there is no draft there.

I was thinking of blowing insulation into all the walls, but what about the ceiling? is it easy to blow into that as well? I was also thinking of blowing into the garage ceiling as well. I was thinking that the lack of attic space above causes a large loss/gain of heat as well, is this correct? I love this room and don't want to be unable to use it comfortably when weather is bad. Does anyone have other suggestions on what I could do with this room?

I guess I will add that the room does have around a 6 foot radiator which does warm the room when it's on, only problem is that the thermostat is in the living room on the 1st floor which is about the furthest point from this room.

Thanks

As the room was an add-on sometime later, it does not have it's own heat control, just one from the other room. Have a plumber check it out. Check for older knob and tube wiring which you don't want to cover with blown cellulose. If none, go for it. You will need to gain access above the garage ceiling to stop the air flow. The room's ceiling may need additional furring to get the required R-value there, or just spray foam it all, roof, walls, and floor.
Be safe, Gary

Thanks for the input, but your response brought up some questions. Are you talking about a second heating zone? like a 2nd thermostat that can control the heater? I have steam heat and no AC if that matters.

Currently the house has a circuit box, but I know that some of the house has older looking wire that isn't color coated (both are black), is there a way to tell if it's knob and tube? I know what the knobs and tubes look like but never saw it in the wall. The wires are in a black sheath to each plug and switch, I thought KnT was run separate. I know the house was owned and probably built by wealthy folk (2 pipe steam, fancy molding, etc), was there some alternative to KnT that could have been used? I know the house has a updated electric box and I just had all of my outlets grounded. The room was added on but unless I open the wall up and look i don't know if it is KnT for sure at a thought. So if the wire was once KnT what do I have to do with that? Do I lose the ability to use blown in? Whats the cost like to have newer wire pulled in those outlets?
Whats a furring?

Thanks

"The wires are in a black sheath to each plug and switch, I thought KnT was run separate." --- correct, sounds like you have Romex, early installation. With the wiring grounded recently, you sound good to go. You can cellulose the walls and two ceilings, adding a vapor barrier primer paint inside, if required by your local building department. I'm surprised the floor slopes. This would be an expensive or knowledgeable fix. The R-value required for your location may require the roof/ceiling framing to have furring (additional wood) members to get the thickness of insulation in there. With that many windows, it will be hard to insulate well and get the whole assemble wall R-value requirements. This on cellulose: http://www.karg.com/pdf/Insulaton_density/Dense_packing_Allwein_and_Biddle.pdf http://www.ornl.gov/sci/roofs+walls/insulation/ins_16.html
Be safe, Gary