Exposed pipes in attic - insulate attic?

[LLC01]

Background: The previous owner of the house ran pipes for an addition through the attic of the garage. The first 3 years we lived there, we had only problems with freezing in extreme temperatures as our heat pump was up there, which apparently generated sufficient heat to keep anything from freezing. We no longer use the heat pump (its old/dead/inefficient and only heats one room in the house), and we had our pipes freeze and burst twice last year, even when the temperature was barely below freezing. The rest of the garage is insulated, just not the walls or rafters in the attic portion.

We had shut off valves installed and currently turn the water off to the addition anytime the temperature dips below freezing. While it works, it is a pain and we would prefer to only resort to this in extreme temperatures. The pipes and elbow joints are wrapped with foam insulation. I would like to avoid using anything that requires electricity up there for fear of fires (IE space heater).

Here is my question: We were thinking of installing batt insulation (with proper ventilation using baffles) in the entire area (exterior walls and attic rafters). Is this a waste of time, or do you think it would work? There is insulation in the ceiling - should this be removed to allow the heat from the house into the garage? Any other suggestions or things to watch out for?

 

[Reach4]

If you are looking to insulate your roof, I suggest you add "conditioned space" to your research terms. That may include reducing ventilation.

 

[Sponsor]

 

[Terry]

I encourage batts over the pipes in an attic. I don't put foam cell insulation around the pipes. You can either heat tape them in the garage, or hope that the garage stays warm enough for the pipes. Often it will be. Pipes in an attic do freeze unless covered like a blanket. The air in the attic can be much colder than the air in the garage if the door is kept closed. The ground retains some heat. You don't see garage floors freezing.

 

[Jadnashua]

Is your garage heated? If not, insulation probably won't help. Insulation only SLOWS the loss of heat, it doesn't generate any. Depending on where you live, the incoming water might be close to freezing, and then, it doesn't take much, especially if there's any air movement, to freeze the water in the pipes. The closer to the heated room (under the insulation), the better. If the garage is not heated, you may want to consider heat tape.