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Insulation Quote and Air Sealing


beagle150

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My home was built in 1955 and has perhaps 3" of insulation with a paper backing of some kind. I have some questions:

1# Is this a fire hazard if left alone? The person who gave me the quote told me this was a fire hazard. The attic is empty though there is some cardboard covering the insulation in spots.

2# He recommended removing the insulation in the attic and replacing with "Open Blow" (R30), installing baffles, etc. Cost $4820 and if we pay $250 for an energy star audit we can save 10% off that cost. Frankly that cost is huge in comparison with the previous estimate ($1200 over the existing insulation).

3# Is there a great deal of sense in Air Sealing crawl spaces and basements (includes sealing rim joist) ?

- MClark

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beagle150

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OT - OF!!!

M.

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If the contractor says there's a fire hazard just because of the paper backed insulation you really have no further need to deal with him. The purpose of the backing is to control moisture entry into the attic from the living area below. Controlling moisture in the crawl space makes absolute sense. But doing this yourself may be adequate and save substantial money. Buy 6 mil plastic sheeting, lay out on the crawl space floor, overlapping 2 -4 feet. Even without taping seams you can greatly reduce the amount of humidity. Now if some significant issue is present in the crawl, more extensive measures may be required.

Insulation contractors, plumbers, framers, home inspectors - there are good ones and there are morons. How do you decide who's who? Your gut feeling is a good start. If what you are being told sounds like it's off the wall, then it likely is.

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Originally posted by beagle150

My home was built in 1955 and has perhaps 3" of insulation with a paper backing of some kind. I have some questions:

I have questions too. Where is the paper? Is it what you see when you go up into the attic? If so, is there another layer of paper on the other side of the batting; and, if so, does that second layer - the one against the ceiling - have a thin black emulsion coating one side of it?

Some insulation products from that era had kraft paper facings on both sides of the batting but the paper is only coated with the asphalt emulsion on the vapor barrier side. That's the side that's supposed to be flat against the ceiling in the attic or against the underside of the floors in a crawlspace.

Insulation made later, usually has an aluminum foil or emulsion-coated paper on only one side and you should see the insulation, not the paper, when the attic or floors are insulated with that.

1# Is this a fire hazard if left alone? The person who gave me the quote told me this was a fire hazard. The attic is empty though there is some cardboard covering the insulation in spots.
Well, lets think about that a second. If it's double-faced insulation and the vapor barrier is against the ceiling where it's supposed to be, and the thin, untreated paper is what's been exposed for the past 52 years, how much of a fire hazard has it been? Sure, it'll ignite if someone sets off a spark over it, but so can the wood framing that's exposed.
2# He recommended removing the insulation in the attic and replacing with "Open Blow" (R30), installing baffles, etc. Cost $4820 and if we pay $250 for an energy star audit we can save 10% off that cost. Frankly that cost is huge in comparison with the previous estimate ($1200 over the existing insulation).
What is the current configuration of the attic? How is it ventilated now? Have you got frieze vents or soffit vents under the eaves or no vents at all? What type of upper ventilation do you have; a ridge vent, some pot vents, or just a couple of gable end vents?

Why does he want to pull the insulation out? If you've got paper-faced batts, and the emulsion-coated facing is the side lying on the ceiling, there's no need to pull them out and then blow in insulation; you can blow the loose fill in directly on top, because the top layer of paper, if it's not coated with the emulsion, is permeable and will not trap moisture. If you add a layer of blown-in fiberglass on top of the paper, you eliminate it as a fire hazard.

If it is insulation with a single facing of emulsion-coated paper, and that paper is on top of the batting, moisture can become trapped inside the insulation beneath the paper. That's not a good thing and it will only get worse if you add more insulation on top.

Around here, the insulation guys either flip that over and place the paper against the ceiling before blowing in the loose fill on top of it, or they slit the paper everywhere with a razor to prevent moisture from being trapped beneath it and then blow in the loose fill on top, or they strip the paper facing off the batting and discard the facing before blowing the loose fill in on top of it. So, again, why pull it all out and throw it away if there's nothing wrong with it and it's still viable?

If it's faced insulation with the batting against the ceiling and an emulsion-coated paper facing exposed, it's upside down. Technically, it's a fire hazard, but as I pointed out, how much of a hazard has it really been for the past half century. The real concern is whether it's been trapping moisture against the ceiling. To find out if it's been trapping moisture, look closely at the top facing. Pull a little of the facing away from the top of the batting and look at the insulation side of the paper to see if there's any black emulsion there. If so, lift up the batting and see if the batting feels damp, whether there's any mold on the attic side of the drywall, or there are any water stains. If not, there's probably no reason you can't reuse it.

He probably doesn't want to spend time flipping it, slitting it, or stripping the facing off it, so it's easiest for him to discard it. However, you could probably do that yourself and save some labor and material cost.

3# Is there a great deal of sense in Air Sealing crawl spaces and basements (includes sealing rim joist) ?
Where you are, maybe, but if you air seal it you'll need to condition the air in there or risk creating a big petri dish that will grow all sorts of nasties that you're not going to want to have under your house.

Does it need to be sealed? Why are you considering air-sealing it and what are the current crawlspace conditions - ventilation, insulation type, insulation location, vapor barriers, etc.?

ONE TEAM - ONE FIGHT!!!

Mike

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Sorry I have no pictures, but I can be more descriptive.

The reason I called the insulation contractor to begin with: We have two levels of roofing. The lower roof has a pitch issue and has been a problem with ice daming ... this roof was replaced within the last ten years (contractor passed away) The upper roof will be in need of new roof shortly (2 -4 years or so I've been told). The upper roof has had ice dams as well but hasn't necessarily appeared to be a big problem. In researching our roof issues and obtaining estimates several roofing contractors suggested we check into insulation.

The house was built in 1955 and is a two story colonial. The attic is empty but has a small decking that runs east west and is centered between the two gables. There is a gable vent on the east and west side of the house. Only about 5 of the 10 soffit vents appear open to the north/south. There is no additional venting. There are some large pieces of cardboard the previous owner put on top of the insulation.

The attic ceiling (tongue and groove) is not insulated. The only insulation is double back fiberglass insulation (per last insulation estimator) along the floor (and under center decking).

The estimator said that the paper backing was brittle and deteriorating and could be easily kindled. The installer said he previously was a fireman (? or similar) and considered the brittle paper on the insulation a fire hazard but that he felt it even more important to remove the fiberglass insulation as he could do a better job of sealing up space under the insulation.

Also, it was stated that leaving the double backed fiberglass insulation in would create a horizontal air barrier (not desirable).

The new insulation would be open blow cellulose ... dead-ending the insulation with foam boards, adding baffles, blocking gable vents, and being sure soffits were open and sealing up areas (I guess little spaces?).

Is blown in fiberglass insulation the way to go on top of this type of insulation rather than blown in cellulose or ??? (based on Mike's earlier reply)

The estimator actually quoted about $17,500 (all kinds of work including the air sealing and basement work ... far more than I was looking for. He discounted the work to $15,000 and then said that if we had a energy audit for an additional $250 we could save 10% off the cost of the work we had done. The work for the attic was quoted as $$6273 but discounted to $4820.

What I liked about this contractor was that he seemed to understand venting issues (balancing vents, soffits, gables) ... some I have talked to have been rather vague about those types of issues.

It has been a real education ... understanding the needs of the house and what really needs to be done. I was the one who chose the contractor for the lower roof which lasted less than ten years and was, as I realize now, not completed correctly. I have decided to take my time on these projects (roofing, insulation) and understand what I need as well as choosing a qualified organization to work with. It has been very difficult to find people I trust to work.

Any thoughts on the subject would be appreciated. I hope my description is helpful.

- M. Clark

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M. Clark, pleased to see you added the period in your signature. Now I can just call you M..

One of our regular participants on this forum is Chad F. He is in the Rochester area and has one of the best understanding of houses in that area. He is a little cranky and not too good looking, but he is smart! Offer him a couple of bucks to come and look at the attic - it will save you lots of money. He is an expert on "reading" the words that contractors often use and he ain't bashful.

Search for him on the members button above and shoot him an e/m or call him.

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If I owned a 1955 colonial in Rochester and if I were having problems with ice damming, I'd be getting bids from an Icynene foam insulation contractor.

Hire your own grunt labor to remove the nasty, useless insulation from the attic floor and to block up the vents. Hire the Icynene guy to spray the underside of the roof. Your attic will be warm & dry, the top of the roof will be cold and there will be no more ice damming issues. You won't have to worry about sealing the ceiling, air bypasses, flammable insulation, gable vs. soffit vents, etc, etc.

Insulating the underside of the roof has way more advantages than it has drawbacks.

(I'm not an Icynene salesman and I have no financial interest in the product.)

- Jim Katen, Oregon

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Hi,

The contractor is right, a horizontal air barrier isn't good, but it sounds like you don't have one. If you're fighting with ice dams it means you've got a lot of hot air escaping into the attic past that insulation.

Jim makes a good point. If you insulate the underside of the roof with icynene and seal the vents you'll turn the attic into conditioned space. As long as it's applied thickly enough, damming won't be an issue. However, if I did that, I'd probably leave the insulation. It sounds like you've got a whole lot of air moving up into that attic anyway via air passages, so there should be enough convective cycling to keep conditions inside that envelope moisture free.

Now that you mention that the contractor is planning to use blown-in cells I have to wonder why he'd bother with removing the insulation and air sealing. Cells is an excellent air barrier when applied densely enough and it's chock full of borate that gets all over everything in sight and pretty much guarantees that you won't see any mold growth.

Les' suggestion to get Fabry out there is a good one. Just make sure the kids are with Mom shopping or at school at the time. There's no sense in traumatizing them by letting them see his face. They'll have nightmares for years! [:-blindfo

ONE TEAM - ONE FIGHT!!!

Mike

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  • 9 months later...

If you could get your hands on a infrared camera (cost around $6,000) you would see one of the reasons why the high bidder wants to remove the old insulation. There could be, well there are unintended holes in your ceiling plane allowing warm air and moisture to enter into the attic, hence ice dams and other problems. A blower door test would also help determine how much air is leaking through unintended holes in the building envelop. If you tighten up the homes envelop/shell make sure you have your CAZ (combustion appliance zone) checked for negative pressure. This can cause natural draft appliance to spill CO into the home.

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