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christineka 01-18-2012 12:41 AM

Need advice: insulation (long)
Sorry to put this here, but I need advice from smart people who know and aren't trying to sell me anything. My husband and I have talked to many salesmen who all have conflicting advice, yet all sound convincing! I've researched on the internet, which said something else entirely!

We just moved into a new to us home. It is 11 years old. Nearly everything is original.

First of all- it's cold in here! I used to keep the thermostat at 66 in my old house, but it's at 70 here and I still think its' cold. Part of the problem is the average grade windows. Our old house has the fancy shmancy ones. Windows, however are too expensive right now. The utility company gives us a rebate for adding insulation. The insulation guys all wanted to put in roughly the same height of insulation, but that's the closest they agreed. The guy who talked a lot (best salesman) said that since we have sloped ceilings, we don't have to put insulation around the edges (since there wouldn't be enough room). He gave us the lowest bid for the job, but that's probably because he was putting in less insulation. The other 3 guys measured the size of my roof to come up with their figures. I have cellulose in the ceiling now. The talkative guy gave me a quote for cellulose. One guy gave me a quote for both cellulose and fiberglass. He was just going to give me the cellulose quote until he saw someone else gave me a fiberglass quote. Fiberglass was $300 cheaper. I talked to one of the fiberglass-only quote guys, who told me cellulose was cheaper than fiberglass, which was why the first guy wanted to sell me cellulose. He also said that if there's no extra insulation on the edges of the house, all the heat will go out there. He said cellulose is no good because over time it will flatten and then be no good. I read on the internet- and the guy who gave me quotes for both told me that fiberglass is no good in extremes of temperature. (Not sure at what point the temp is "extreme". I live in Utah where there are 4 distinct seasons.)

So now I must make some sort of sense and I really don't know. I'm not an expert! Do I put in cellulose or fiberglass? Do the whole ceiling area or just where the roof is higher?

TarheelTerp 01-18-2012 07:45 AM


Originally Posted by christineka (Post 826468)
I need advice from smart people who know and aren't trying to sell me anything.

So now I must make some sort of sense and I really don't know.
I'm not an expert! Do I put in cellulose or fiberglass?
Do the whole ceiling area or just where the roof is higher?

Stop asking sales people for technical advice.
Learn what you NEED from objective sources and then shop *that*.

With the insulation question you need to evaluate the house in it's entirety which many utility companies help with or will do for free; but you may also need to hire pro's for this information and help just like an architect or accountant would be.

poke around on this site:


gma2rjc 01-18-2012 09:19 AM

Here are a few things I learned when I started sealing my attic and when I was going to have cellulose blown in.

First, I didn't even know that my attic needed to be sealed. Most people don't know that. All attics need to be sealed before being insulated - if they're not already sealed by the previous owner or when the house was built.

From what I understand, when a house is built, sealing the attic has to be negotiated into the contract. It's not something that's automatically done before the insulation is installed.

I went online and read everything I could possibly find about insulating an attic. Do that. Learn as much as you can so that when you're talking to a salesman you will know what questions to ask. You will also know if he is b.s.'ing you. If you know he is lying to you, don't hire him. He's dishonest and when it comes to your attic (where you will NOT be able to check his work) you need an honest company doing the work.

I haven't seen your attic, so I don't know if the guy who told you that you don't need to insulate around the edges is lying to you. But here's what happened to me. I spent a LONG time up in my attic sealing it. I was 45 and had never even been up in an attic - no experience. But I was very thorough because I didn't ever want to go back up there. So I moved every batt of insulation that was up there and found way more than I bargained for.

After spending a lot of time and money up there, I interviewed a bunch of companies and ended up hiring the guy who seemed the most honest to blow the insulation in.

He blew the cellulose in and when he was done, he had me climb up onto the roof (another first for me) and look down into the attic through a hole he had cut into the roof - to put another vent in. Everything looked great.

This was in the spring. The following winter, when the temperature dropped very low outside, I noticed condensation on my ceilings along the exterior walls in the front and back of the house - big drops of water.

What happened is the guy who insulated the attic didn't get the insulation out to the edges of the attic floor - near the soffit openings. I think your guy is lying about that.

So the cold air in my attic was meeting with the heat rising up through my ceiling and it was causing the condensation to form. Just like in the summer when a glass of ice water 'sweats' on the outside. Water forms on the warm side, which is what was happening on my ceiling.

I was :furious:. When it was nice outside again, I ended up having to tear out my soffit vents on the outside of the house to get to the spots he had missed. I didn't want to go up in the attic and disturb all of the new insulation - or have to remove a lot of it to get to the uninsulated areas, so that's why I did it from the outside.

Here's a link to the thread I posted when I found the water on my ceiling.

If you seal everything in your attic, you'll notice the difference in the amount of cold drafts in your house right away. Even before you insulate. That was something I didn't expect, but it made a big difference because the attic wasn't drawing warm air up out of the heated space down here.

How handy are you and your husband? If you're even a little bit handy, you should be able to go up into your attic and seal it. Like I said, I had never even been up in an attic before I did mine. You're a better judge of your abilities though. You have to be careful not to fall through the ceiling :wink:.

By the way, I've read that fiberglass does lose some of it's R-value when the temps outside drop very low. And mice and squirrels don't mind building nests in fiberglass. They don't like cellulose because it has boric acid in it, so there's less chance of them making a home in your attic.

Like I said, read as much as you can about insulation. You'll be glad you did.

If you read some of the threads on this forum about insulation, you'll see some links that GBAR in WA posts every now and then. Click on those and you'll get the most up-to-date and accurate information available.

Here's a link to the thread I started about the condensation on my ceiling.


Gary in WA 01-19-2012 07:19 PM

Good idea about the free energy check from previous poster. This will tell you what you have now, and whether or not you need different/more.
Fiberglass, blown-in loses R-value when the temp drops way down;
If you get time to read about f.g., here is some I put together:
Really a lose/lose situation, unless it is in an air-tight box covered on six side, as in the lab for the R-value, not the attic with air venting. Or in the wall with air leakage with the house pressure differences, or in a cathedral ceiling with any gaps for convective loops due to temperature/pressure differences. Does it show that I don’t like it…. But- it’s cheap….LOL.
The outside rafter areas are the same as rim joists in a floor = both at perimeter edge- where only 1-1/2” of solid wood is between your heated wall/roof system and the cold outdoors. 1” of wood = 1.25 R-value. WOW. This on rim;
Even in the crawl space on the rim area:
Need that air seal, most important. Just some f.g. batt against it will keep itself warm, maybe a little more…. Nope, scratch that. F.g. is air-permeable, air goes through it, cellulose is way better at stopping air flow (though it is air-permeable also):

Ask if the utility company does energy inspecs, when he’s there; ask the make-up of the roof. I doubt you have insulation on top the roof sheathing, just the cellulose. He should be able to measure that and go from there. You may want to get additional “dense-pack” blown-in by another, here’s how it’s done;
Here is the one I was thinking of:

Ceiling paddle fans push the warm air down on reverse- in winter….

Thank you for the kind words, Barb. I had to answer this one, with links.....LOL.


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