Radiant Barrier/ insullation Delima
 

Hello Folks!
I am researching ways to improve our energy efficiency here and have decided that the most immediate need with the Texas heat is more insulation. I should mention that our A/C Ducts run through our attic which is about 4 feet high... in other words the temperature of our air is raised considerably by the outside heat.

To alleviate some of this I plan to increase the attic insulation to anywhere from R38 to R49 and in addition I'd like to go with a radiant barrier. Here is where I'm torn. The foil variety will give in (in theory that is) a 97% reflectivity witch is excellent, however it can't be installed in an existing home all the way to the roof line and so you loose some of that 97% which matters considering the cost if greater than the spray on "paint" variety. The Heat-Block 75 seems to be the highest functioning of the spray on varieties it has a reflectivity of 75%, but because you can use a long narrow sprayer it will cover completely and all 75% will be retained. At least this is what I've been told.

As for insulation I wanted cellulose (the recycled variety... just trying to go as green as possible) but I have found that the cellulose contains Formaldehyde as a fire retardant and I'm really not keen on the idea of that being in our house especially being that I am very allergic to it... couple that with the fact that cellulose can mold and even with the retardants burn...and fiberglass is looking more appealing to me. There is a type called Jet Stream 73.3 which is not as irritating as the shaved fiberglass... and it is non-combustible, doesn't support microbial growth and won't rot mildew or deteriorate. So I'm thinking this is what we'll go with... and I'm leaning more toward the R49 simply because we have an old 10SEER A/C and it is MUCH cheaper to insulate than it is to replace that unit(which will be replace for a small service fee by our home warranty when it finally gives up the ghost).

What is your experience with any of these products or types of products? I'd like to have some feedback from people who actually have them before I write a check. The ultimate goal is to reduce our bill and make our home more comfortable at the same time.

You would have better luck going to the discussion forum at the Fine Homebuilding website. They have building experts there who will give you decent information. You have to register, but it's free, and valuable.

I can tell you that Reflectix (radiant barrier) is an easy install but I second the Finehomebuilding site if you want to know about its usefullness.

Pooka is my lovely wife, and mother of my two amazing children; in case you didn't know. So I can't help but feel responsible for our house being full of "hot air" if you know what I mean--waka waka! But the main problem is that spellcheckers haven't been invented yet in Texas.

If my responding in some way causes you to spend a hot summer day crawling in your attic, I humbly ask for your forgiveness.

you don't really think flint would make the beautiful mother of his darling children crawl through the attic on a hot texas summer day, do you griff? think of the children flint. the children.

No. I was responding to flint. I fear the love of his life has an evil plan.

Honey if you take issue with my spelling... you try writing anyrhing on here while supervising 2 in the tub and one on your shoulder...
I love you

I'll confess... Flint isn't the only one with a "hot wind"roblem... hahaha

Make that Anything... and problem... yes spelling is clearly an issue

hey... you can edit your posts for a short time after submitting them. not necessary to make a whole new post.

Not that there's anything wrong with that...I'm just sayin.

Coolest part of your house is sitting all but exposed to hotest air. Essential is to construct a frame around those ducts and insulate the frame. This can be done with lathe and is best done with fiberglass insulation. Anything you do after that will be helpful. But the best insulation must enclose round those attic exposed air ducts.

Also consider fans for attic airflow?

avoid fiberglass like the plague it is. The cellulose which we put in doesn't have formaldehyde (I wonder who told you that) it has boric acid as a fire retardant and insect retardant. Boric acid is what is used in eye wash. Very harmless unless you are a powder post beetle or termite.

You definitely want to wrap those ducts with as much insulation as practical. 2" foam blueboard is great stuff. you can put 4" of it on and you'll be all set. Jam it right up to the roof sheathing and use spray foam to fill any cracks. The key is eliminating any air infiltration/movement.

And remember while hot air rises, heat moves in any direction toward cold. Heat wants to give up its energy and moisture to cold. Heat is like that. Air, on the other hand goes up when it's hot and down when it's cold.

You might also want to add soffit vents and a roof fan to let out the worst of the heat. I live in the asshole of Texas and I just bought a house that is 100 years old. I have a LONG list of things to do. I'd post pics and the video if I could find the wire to get them off my camera.

We looked at a 100yo house, but settled on a 50yo because the construction materials were things I could recognize, and wouldn't be afraid to tear apart without knowing how to put them back together. Some friends of ours ended up buying the 100yo place we looked at. We're in a nice little historical district where one house may have goats in the yard and the next may be a huge, old mansion. And then there are street like mine, i.e. Pleasantville. Our neighbors are little old ladies--it's like having a free burglar alarm.

That's what my dad always said about our street. But it took him a long while to get used to the incredible nosiness of those same neighbors.

My wife doesn't mind the nosiness, as long as it generates a long-winded chat session.

She's stuck at home all day with two little people who are not very articulate conversationalists.

And when those two little people get older, they will fiercely resent it when they try to sneak out, and the damn neighbors with their binoculars rat them out.

Borates are great and I plan on lining the attic with it, but still the Formaldehyde concerns me... along with a few other considerations... here is a "green site" that discusses it:

http://www.greenbuilder.com/sourcebook/Insulation.html

"Cellulose insulation uses recycled newsprint that contains printers inks which can possibly outgas formaldehyde into a home. If there is any outgassing from inks, it should fall well below levels irritating most persons. However, an environmentally-sensitive person should be careful in selecting cellulose and install a vapor retarder between the insulation and the living space. (Note that the vapor retarder can exacerbate mildew problems if humidity levels in the house are high.)"

Old folks - Check!

Got two sets, one of which, despite being 80+, managed to get out of his chair, outside and peeking through the "hedge" to see what I was having delivered (Wonderboard). When he couldn't identify it, he stayed there, puzzling it out until he finally tried asking me. In Spanish. Which I do not speak well. So I just smiled and shrugged and told him I do not speak Spanish (one of the phrases I memorised early on) and went back inside.

Do you live here, Flint? I thought you lived over in Austin or someplace?

Brian

He's up in the metroplex.

How many Texans are in the Cellar? And with old people all around? And with attics in need of more or better insulation? How does one say "Yikes" in Texanese? But keep the info coming, I'm learning good info.

Ok... I'm still torn. I've seen to this magical website of which you speak... and it is a bit more technical than I can handle at the moment. Figured... as there seem to be at least several of us hot Texans here I'd continue my thoughts on the topic.

Ok... so save for the ink, the cellulose is starting to look good again, but even so.. the Fiberglass I've looked at is certified by the Greenguard Environmental Institute for even the more stringent For Children and schools standards... and is an Energy Star Partner. No Cellulose insulations seem to meet those standards.

The more I research the more I am unsure of what to do. I'm even flipflopping on the radiant barrier... I'm now thinking that the foil variety is the way I want to go. I'm just wondering if there is any truth to what I was told... that with retro fitting you lose some of the effectiveness as it is not possible to get all the way down to the roofline with existing insullation in place. Thoughts anyone?

I should mention that while I'm not opposed to a DYI situation ... I want it done correctly... that is not to imply that Flint isn't capable of perfection... lord if anyone knows of his ability to strive for perfection it is me (and he most always achieves his desired goals), but he is so busy with work and school that the chances that it would be "himself" doing the install is slim... more likely would be another family member... who is also very busy and slow to complete projects... so paying a bit more for a professional and speedy job seems worthwhile to me.

Forget what you read, go stick your snout into a pile of cellulose insulation, there is no formaldehyde. I know, my whole house is filled with cellulose, I've worked on dozens of jobsites where the stuff was a cloud in the air. I know the smell of formaldehyde from my photog days and from the eye watering stink of fresh plywood. Any formaldehyde which may have been present in the ink (I seriously doubt this too) has long since evaporated.

THis opinion and $1.50, will buy you a cup of coffee. (not at starbucks) then again, you can run but you can't hide: http://en.wikipedia.org/wiki/Formaldehyde

(PS don't tell Clodfobble I linked to wikipedia)

As for certification, if you are willing to pay enough money you can have dogturds certified as safe. You must do your own research. Fiberglass is a carcinogen. PCBS are perfectly safe, ask Hudson River Voice, the folksy sounding grass roots organization which is a front for General Electric, who didn't really feel like spending millions and millions of $ to clean up their mess.

How much time do you plan on spending in your attic crawlspace anyway?

I'm a big fan of blown in insulation whether it is foam or fiberglass or cellulose. They each have drawbacks and strengths, what they all have in common is that by blowing the insulation in it fills all the nooks and crannies which placed insulation missess.

Good luck.


Oh there is also Adobe, I hear that is the real deal for the hotter climates...

Or put a lawn sprinkler on the roof.;)

Who what now? I'm a big fan of wiki, I use it all the time... :confused:

So you say:rolleyes:
http://www.cellar.org/showpost.php?p...&postcount=711

Dang it! Kagen didn't get the joke, and clearly no one else did either.

See, it's like he made a wiki entry, and then I edited it to fix his grammar and spelling and add an encyclopedic definition of the term... ah, whaddayou guys know about humor anyway.


I should have put [citation needed] at the end to make it better...

I don't have anything useful to add about insulation, or attics, or old people . . .

er.

But I would just like to say, everytime I see this thread, I think it's about aliens or space particles or something.

Radiant barrier--is this some kind of interspace membrane?

insullation Delima--sounds like Dejah Thoris' cousin; some kind of pouty empress throwing a party!

(sorry, Pooka--)

As my sister id fond of telling me,"Leave humor to the professionals.";)

I just saw your post over there and the responses. I'd consider giving the most weight to the posts made by Andy Engel. He's one of the editors at Fine Homebuilding magazine and is quite knowledgeable. That Piffin guy is also pretty experienced, but he's from Maine, so I don't think his greatest expertise is in Texas insulating needs.

glatt is stalkin' mah wife

We need a lolcat image for that caption

Insulation
 

Cellulose insulation has it's own drawbacks, most of which are not well publicized.

Cellulose is made with chopped newspaper that is hammermill treated with boric acid and borax.

While it is cheaper than rock wool or fiberglass it has it's own design defects. Under extreme heat conditions as here in Arizona the boric acid and borax migrate down in time and then leave an attic full of exposed unprotected chopped paper. Makes a beautiful flashover when exposed to fire. There is also the fact that the boric acid and borax mixture is corrosive and should not come in contact with metal ducts, pipes or light fixtures.

Yeah, I know, in many cases it has a UL listing. Well, many things that are listed work well in other climates and other parts of the country but Arizona seems to be the ultimate test facility and by default many of those things fail here. We did an accelerated life test and ended up with exposed newspaper. Not what I want in my attic.

Fiberglass remains the industry benchmark for insulation. Other types are used when installation makes fiberglass difficult.

Your first problem is the hottest or coldest part of the building exposed to outside (attic) air. That is where the insulation must be thickest. Four inches of any insulation is 1950 standard when energy was cheap. Six inches minimum. Around heating (cooling) ducts, insualtion must be thicker than in other locations. Three or four inches of insulation in ceiling regions is unacceptable anywhere in America - except where the rooms are unheated or uncooled.

Since insulation around ducts must be high (not flat) and not compressed, then fiberglass around those ducts is a simplest solution. Insulating around those ducts would be the first task regardless of what type insulation gets used in flat sections.

Thermal barriers (ie paper backing or metal foil) are the vapor barrier. A vapor barrier must exist where insulation meets inside air or touches sheet rock. In your case, insulation already exists. Putting insulation with a vapor barrier over top of existing insulation does nothing good for you; may create a problem. Obviously blown insulation does not have that vapor barrier. Fiberglass bats without a vapor barrier is purchased where fiberglass gets installed over existing insulation.

Air ducts are all but exposed. Insulation with a vapor barrier is installed here; would be useful and make the task easier to attach that insulation to a frame around those ducts. That paper backed or foil backed insulation gets stapled to a frame around air ducts (and anything else that requires separation from insulation such as embedded light fixtures).

Do you have large light fixtures embedded in the ceiling and exposed in the attic? These should also have insulation over them - not insulation blown into them. IOW before installing blown type insulation, some formed insulation (ie fiberglass) should be installed over these fixtures so that blown insulation is not blown into these light fixtures. Electrical light fixtures must breath. Many blown insulation installers don't do this; don't keep their insulation out of those embedded light fixtures.

If any electrical junction boxes are not properly covered, those covers MUST be installed before installing insulation. Insulation (especially blown type) inside any electrical junction box can only create a future hazard.

Your insulation will be higher than existing ceiling beams - typically 2x6s. Therefore insulation will pile up to the roof where ceiling beams meet rafters. This is a major vapor problem. A problem typically alleviated by installing styrofoam air channels. These channels hold the insulation maybe one inch away from the roof so the roof does not rot.

Insulation above those ceiling beams means attic spaces no longer are storage areas. To use the attic for storage, wood is placed above the ceiling beams. Then insulation installed. Now a floor (ie plywood) can be nailed above that insulation so that attic storage is possible.

Insulation works by expanding. Any insulation that is compressed becomes closer to no insulation. One problem with some blown insulation is that it compresses with age. Another advantage of fiberglass. It does not compress with age. As insulation compresses, its R rating decreases. Higher R means better insulation. Compressing insulation (with age or with storing items on top that insulation) reduces its R rating.

Attics must breath. Air from the soffit must flow up into the attic via those air channels, then out via roof vents or attic fan. Note the previous reference to an attic fan or another's reference to roof vents. You must have that ventilation so that air flows up through the inside of roof wood.

Cellulose or other blown materials can only be used where insulation lies flat. Where insulation is on an angled or curved surface, then fiberglass is typically used. Therefore the fiberglass is installed over those curved surfaces before blown insulation is layer into flat surfaces.

Any hole in the insulation means insulation around that hole is compromised. Properly installed insulation also takes scraps to fill any gaps. These gaps are why blown insulation is easier to install. No one must carefully fill holes between insulation bats or cut the fiberglass so that it encases (goes around) wires and other existing items. If the wire crosses from beam to beam, then fiberglass bats must be cut or separated so that insulation lies uncompressed on both sides of that wire. Inferior installers will just lay insulation over that wire and press the insulation down.

Insulation laid over any wires must also not press that wire to the sheet rock wall. Wires must always remain two inches away from every sheet rock wall so that nails hammered in any wall years later do not penetrate that wire. This workmanship is why many avoid fiberglass bats; use blown insulation.

Any type of insulation must be installed wearing a mask. All insulations fill the air with unhealthy materials when being installed. Mineral type insulations continue to fill air with hazardous (asbestos equivalent) materials after installed. Stable materials such as fiber glass, fiber boards, and some blown type insulations tend to be safe after installed. However outgassing from some blown type materials remains a problem denied by those manufacturers - ie formaldehyde. Outgassing is especially problematic where insulation is installed in confined spaces (ie walls). That outgassing goes into a house; not outside through the vapor barriers. Another reason why fiberglass is so highly recommended - no outgassing.

Just a few pointers to consider. Other responsible sources should have discussed these and other facts.