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Heated garage-insulate roof?

daash220's Avatar

Join Date: Jan 2006
Posts: 1

01-21-06, 06:37 AM   #1  
Heated garage-insulate roof?

I recently added heat / ac vents to our attached garage. I know that there is alot if heat loss in the winter through the roof of the garage because there is no ceiling. Is there a way I can add insulation between the rafters of the roof to hold in the heat and the air conditioning in the summer? Any help would be appreciated.

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Concretemasonry's Avatar

Join Date: Mar 2005
Posts: 6,125

01-21-06, 07:51 AM   #2  
Heated garage-insulate roof?

If could help, but you must have ventilation between the insulation and the roof.

You will never get athe garage like a house, since you are trying to push air into and area (the garage) that has no air return. For obvious reasons, you cannot have a return from the garage to your house system.

In the long run, you may be better off shutting down the heat/air to the garage and go with a type of heat designed for a garage.

Your car obviously does not need the heat (unless it is a 1953 Oldsmobile Corvette prototype @ $7,000,000). Radiant could be more effective and faster if you are working there in your cool winters.

In any event. insulation in either the roof or above a ceiling. A finished ceiling reduces the volume you will have to heat.


manhattan42's Avatar

Join Date: Jan 2006
Posts: 143

01-21-06, 08:47 AM   #3  
MAJOR Code Violation

As ConcreteMasonry said, what you have done is a serious and major Code violation and serious safety hazard in most every US location including New Jersey.

Attached garages CANNOT have ac/or heat ducts into them because the garage is required to have a fire seperation between it and the habitable space and open ducts and vents compromises that fire seperation.

Ducts and vents also cannot terminate into a garage because it provides for carbon monoxide and other deadly gases to enter the living space through the ducts.

Many have died and been permanently maimed by doing exactly what you have done.

Before you go any further, have your current situation reviewed by your local code enforcement office, immediately block the vents to the garage, and do nothing more until this dangerous condition is rectified.


New Jersey Code:

R309.1.1 DUCT PENETRATION. "Ducts in the garage and ducts penetrating the walls or ceilings of the garage shall be constructed of a minimum No. 26 gage (0.48mm) sheet steel or other approved material AND HAVE NO OPENINGS INTO THE GARAGE."

You will need to find some other way to heat and cool your garage but using your current AC/forced air system is absolutely not acceptable and highly dangerous.

Last edited by manhattan42; 01-21-06 at 08:59 AM.
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