Insulation and wiring question

[beagle150]

We have insulation laid on the floor of our empty attic - been there probably for 40 years or so. The paper backing is now quite brittle.

We also have some wiring laying on top of that insulation: (1) extra phone wire that dead ends in the attic and (2) some wire that I believe was laid in by a security company. I know that vents, lights and the like must have some kind of housing around them - is wiring of the type I mention an issue when it comes to laying new insulation on top of it?

[hausdok]

Yes,

1. If the paper side is facing up, and it's coated on one face with an asphalt emulsion and the paper on the other side of the batt is ordinary paper with no emulsion coating it, than it's upside down.

2. Exposed paper is, as you've observed, a fire hazard.

3. If the wiring is 40 years old it's the old 60°C stuff and shouldn't be buried. Raise it and install the batting beneath it; keeping the wiring on top so it can cool.

OT - OF!!!

M.

[beagle150]

Originally posted by hausdok

Yes,

M,

To clarify: the paper side that is facing up is brown and does not look like it is coated with anything - it's brown ... does this mean it is upside down?

You mention exposed paper is a fire hazard. Mmmm? Not a soul - has mentioned this too me. Well, actually one person mentioned it but he had quite a sales pitch and a truly astronomical price. He mentioned it quite off-hand - the way it was done it seemed more like a scare tactic. Everyone else seemed clueless when I brought it up - including the home inspector. Geez, how likely is it to ignite (nothings up there but the heat and the insulation).

The house was built in 55, the insulation might have been there since then or perhaps it was put in 30-40 years ago. The wiring seems newer --- the phone wire is coated in "grey" and the other is colored white, red, etc.

- MK

[StevenT]

Mike,

It sounds like the wiring he's talking about is all low voltage. Do you still think there is an overheating hazard?

[hausdok]

Hi,

Steven, I think you're right. Sorry, the type of wiring went right over my head until you'd mentioned it.

Some old insulation batts have brown paper on both sides. However, when you peel back the paper, there's often a black asphalt emulsion on the side of the paper that you can't see - on only one side of the batt. The side with the emulsion goes down on the ceiling and the other side is left exposed. Back in 1955 nobody was worrying about the exposed paper; that didn't become a concern until years later. However, you'll need to be careful to make sure that the vapor barrier side of the original batts (the emulsion coated paper side) is against the ceiling and not on top of the insulation when you add more on top; otherwise, you'll place a vapor barrier in the middle of the insulation. You'll also want to use either unfaced insulation or permeable sheath encapsulated insulation on top so that moisture can move freely up through the insulation and can't become trapped.

ONE TEAM - ONE FIGHT!!!

Mike

[beagle150]

Mike, Steven and all,

Thank you for the clarification on the insulation. I will check it out.

Sounds like you are saying that there is no fire hazard with the brown wrapping if the wiring is low voltage and that it is okay to lay new insulation (properly) on top of the wires.

- MK

[StevenT]

If it were my home, I would probably prefer to see the wires stapled across the rafters rather than buried. Not for fire reasons, but to protect the wiring and keep it out of the way and so if necessary, you can access them in the future.

If you should decide to staple them, make sure you use the proper staple and staple gun. You want a rounded staple so you don't damage the wire.

As far as being a fire hazard, if you are concerned, it is easy enough to peel the paper off and get it out of there.