Insulation Material

[Bob]

I am in the process of adding rafter vents to clear ventilation from my sofits up to my ridge vent. Unfortunately I discovered that the blow-in insulation had fallen down onto my sofit vents preventing any air flow. My builder was grateful enough to supply me with enough baffles to do both front and rear sections. Since the ones the builder uses only extend up about 2 feet, I am going to add the standard pink rafter vents to them to extend my reach. I was told however that I should insulate around the two chimneys coming from both my gas water heater and my gas furnace to prevent any heat loss into the Attic space. Could you recommend a material I could use for this purpose. I do have limited access from the inside where the pipes extend through the ceiling. I wasn't sure about the flammability of standard rolled insulation against the pipes. Currently I have blown-in mineral wool. I wasn't sure if I could stuff additional cellulose in the area as I probably wouldn't be able to find mineral wool at retail level. Thanks in advance for your help.

[Mark Bower]

I would assume your vent pipes are double lined, right (i.e. one pipe running inside another)? If so that should help against the pipes getting too hot. Generally you are fine with fiberglass insulation as it's non-flamable. You may also be able to get a type of fire-stop caulk that takes heat and put around the pipes to help seal them from air.

Mark

[Bob]

Thanks Mark, I do believe they are double wrapped.