When wood is treated, the ends are sealed. When it is cut, it provides a path for water and rot. In a perfect world, the ends of the cuts would be sealed with wood preservative before installation — and no, I don't think this was the cause of your premature failure.
Q: Are there any circumstances under which you would not want to use the new sealed insulation rolls? They seem much safer and more convenient than having to handle and breathe the unsealed fiberglass. I just worry there are vapor and moisture issues that would cause even more problems.
A: Encapsulated insulation, for those who are not aware, is well, encapsulated in what I would loosely describe as a plastic cocoon.
It is very convenient, but slightly harder to cut and more expensive than unfaced (raw insulation) or Kraft-faced (paper).
On new construction exterior walls where vapor barriers are an issue, it is more efficient, faster and cheaper to use un-faced and put plastic over the entire wall, or paint the entire wall with a vapor retardant primer as required.
Kraft can be face-stapled, unlike most of the encapsulated I have run across, which enables a bit more installation flexibility. So each type has its advantages.
Breathing insulation is not a factor, since if you are working with any kind of fiberglass insulation, you will be wearing a respirator or at least a paper mask, won't you? (Don't make me repeat that last sentence — read it again!)
When you cut encapsulated insulation, you are releasing fiberglass, so what you are breathing is an issue either way. Encapsulated may prevent you from feeling like you immediately need to run to the shower if it is a small project, so that is another huge advantage.
I can't help laughing to myself about insulation vapor barriers and how they relate to homeowner-performed insulation projects. Nine times out of 10, if you look at faced insulation that was installed by a homeowner in an attic or crawlspace, it will be backwards.
Amateurs want to hold the vapor barrier, not actually touching the insulation, and push it into the cavity. That works great in our "heating climate" in an exterior wall only, but that method is backwards in an attic and a crawlspace.
The big bold letters on each and every piece of insulation say, "INSTALL THIS SIDE TOWARD THE HEATED SPACE." Vapor barriers go on the warm side of the insulation (unless you are in Florida). Reverse it and you are trapping moisture after it has condensed on the cold side of the insulation, and then you can get mold.
Don't freak and tear out all the insulation in your attic and crawlspace tomorrow. Reversing a paper vapor barrier has never resulted in major consequences to my knowledge, but get a sheet of plastic vapor barrier backwards, and it will happen quickly.
More likely to cause damage related to condensation than backwards insulation is leaking siding, lack of roof venting and insulation covering roof vents.
I am thankful to an amateur insulator who went a little bit nuts, insulated everything he could find, and created mold and rot in the attic as a result — his screw-up allowed me to get a great deal on a house last month that needed a bit of work as a result of the interior terrarium he had going on.
Darrell Hay is a local home inspector and manages several rental properties. Send your questions |
