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Cellulose Insulation Installation

Insulation contractor Rick Davenport shows Bob how they install wet-spray cellulose insulation into open walls. The material is typical cellulose insulation, simply recycled newspaper. It's the installation system that is unique. Small jets of water moisten the insulation as it leaves the nozzle of the blower hose. The damp cellulose sticks to the studs and exterior sheathing, completely filling the wall cavity. The moisture will dry before the interior drywall is installed, so it doesn't harm the wall or affect the insulation value of the material. A large rotating brush, called a stud scrubber, removes excess material and cleans the inside face of the stud. In the ceiling, a blown-in-insulation is used. Plastic netting has been stretched along the bottom surface of the ceiling joists to support the material. The end of the blower hose is inserted through the netting to fill the cavity. Instead of adding water as the cellulose leaves the hose, an adhesive binder is mixed with the cellulose before it leaves the hose. The binder helps achieve a controlled density that provides a uniform insulation level of R-3.7 per inch, which comes to R-37 in this 10-inch cavity.

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Cellulose Insulation Installation

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" is cellulose right?"

" That's correct, it's recycled paper."

" Recycled paper and of course it's a very responsible way to insulate your house 'cause you're not using up any precious natural resources."

" Uh huh."

" What's different about this process?"

" What we've done is we treated it so it's completely fire safe, and then we we're gonna add some moisture to it and spray it into the wall cavities over here."

" So the installation process is different."

" That's right, that's right."

" Let's look at that, the end of that hose if we could for just a minute. Whooow, now you got the the insulation will be coming out in here, but what are all these other branched nozzles?"

" What we've got is [unk], we're going to introduce moisture to a dry product coming to the center"

" Uh huh."

" somewhere about a foot out here, then we're gonna throw it into the wall, and that causes it to stick."

" Now, does that prevent it from settling down in the wall cavity, cause I know a lot of people are concerned that this kind of insulation might not stay uniformly spread."

" Well, what we're doing, because we're filling it harder in the cavity, it has a tendency to swell rather than to settle."

" So, you're packing it in tight?"

" That's correct, that's correct."

" Doesn't that affect the R value? Don't you have to have air spaces in between the fibers?"

" No, well cellulose has a or paper as an inherent ability to control the R value within the fiber itself. It's a hollow fiber."

" The fiber in cellulose is hollow."

" That's right."

" So they just do always have air. Now, of course, we were talking about the concern of having moisture get into your insulation which occurs with fiber glass is a real problem, and here we're adding moisture on purpose. How does that work?"

" Well, we're adding moisture to make it stick in the application phase of it, but moisture really doesn't affect cellulose or paper like it does with fiber glass because it's constantly picking out moisture and letting moisture go. Like a towel when you put it out overnight, in the morning time it will feel moist then during the day, it would dry up. It's hard to understand how you're gonna live all these wet stuff in the wall then go put the plaster board up and what should be trapping all the moisture in there?"

" Oh no, this is the amount of moisture they're putting in here will be virtually dry within a day or day and half."

" I can see that it really sticks well, but isn't it kind of lumpy?"

" No, what we're gonna do now Bob is we're going to take the studs scrubber and"

" Is that this thing here?"

" Yeah, yeah."

" We're gonna sheen it back off to the face of the studs."

" A stud scrubber."

" Uh huh."

" It's a pretty specialized tool. It just got a lot bristles on here."

" Uh huh."

" Now, let's watch them do that. Well that does a real nice job of cleaning up the whole, the whole wall and the stud, huh?"

" Yeah."

" How do you go about installing it up in the ceiling?"

" Well Bob that's a little different application. Well Bob, here we have a little bit different problem. We're dealing with gravity, so we're gonna use the bead system. In the bead system, we use an insulated mesh that allows the air to breathe as he's installing it. We're gonna install it with a binder and air where it's mixed unlike the nozzle that we use to spray at the end of the hose. It's mixed actually in the hose here."

" So you've got in this red hose, you're adding compressed air and what's the binder?"

" An adhesive binder that goes into it, and the reason we do that is that it will give it a controlled density to that we don't have any settling. Here you go. Now, this ceiling is just below our patio off the master bedroom and in the hot California sun, we're gonna have some real high temperatures there. What kind of an R factor will we get?"

" We get an R factor of 3.7 per inch Bob. That's gonna give us a 37."

" An R-37?"

" R-37."

" We have 10-inch cavity. That's terrific. We'll one big advantage of course is that it's a natural product and what other advantage does this have?"

" Well, it's an effective alternative to fiber glass Bob and the main thing is that it's a recycled environmentally product."

" What about sound detenuation?"

" Well, cellulose years ago was designed to be a sound deadening product."

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Blown-in Dense-Packed Cellulose Insulation for the Roof

The roof of the new addition is being insulated to retain all the heat generated from the radiant heating system. Paul Johnson of Alpine Insulators reviews the installation process. The first step involves installing netting that is breathable so air can escape once the cellulose is installed. The netting is fire-retardant and stapled in place to hold dense-packed cellulose in place. Bales of cellulose are emptied into a machine located in an on-site truck that shreds the cellulose before pumping it at high pressure into the cavities of the roof. In this case, the insulation cost about $2.25 a square foot. Cellulose is a great thermal insulator and sound attenuator. In the interior partion wall where the bathroom will be located, cellulose will be installed directly against the drywall. Bill Hulstrunk of National Fiber reviews some of the properties of cellulose insulation, which has been around since about 1920 and used extensively since 1970 in both new and existing construction. Borates are added to make the cellulose fire-retardant, and mold and insect resistant. Because of the added borates, a propane torch can be put to the cellulose without igniting it. In a field test, a penny can be put on top of the cellulose and melted without the heat penetrating the material. These borates are naturally occurring and the cellulose itself is made of 83 percent recycled content, making this type of insulation an environmentally conscious, "green" choice. The cellulose in this house is being used in an unvented application. Because the material is packed very tightly, it reduces the chance that warm, moist air will penetrate the cavity and create mold growth.

Blowing In Cellulose Insulation

Bob meets up with Joe Sheridan from Energy Guard to learn more about the US Greenfiber Cocoon cellulose insulation application that is taking place in the barn. This is not a do-it-yourself process. A mesh material is first attached behind the wall cavities to hold the cellulose in place until the drywall is applied. The cellulose is essentially ground up newspaper treated during the manufacturing process with borates to resist fungus growth. It's mixed with a litle moisture and blown into the stud cavities. Product that falls onto the ground is vacuumed up and sucked back to the truck where it is remixed and blown back out. While one installer blows the insulation in, a second man follows with a stud scrubber, leveling the cellulose with the studs. The goal is to create a tight fit eliminating air movement through the wall. One can achieve an R-factor of R-13 in a 2 x 4 wall and an R-21 in a 2 x 6 wall, R-factors that will be maintained even in extreme temperatures. Within 24 hours after application the moisture content drops below 25% allowing sheetrocking to proceed. Another benefit of the product is sound attenuation. Upstairs in the attic, Joe's crew is doing a dry application. The cellulose is blown in under pressure. The hose is fed down to the bottom of the cavity and pulled back as it fills up. A proper vent in the ceiling is not necessary because the insulation is so dense that air doesn't travel through the insulation and miosture therefore never gets out to the roof sheathing. The price of the Cocoon product is comparable to fiberglass insulation.

Insulation Basics

Here's another great tip from BobVila.com. How much insulation does your home need and where? It depends on your climate and the energy costs in your area. The basic principle is that you want to keep heat energy from doing what it does best: dissipating to colder areas. The best way is to trap a layer of air next to the heat source. In new framing, sprayed-on polyurethane foam, fiberglass or cellulose do a good job of providing this layer before the drywall goes up. If you re retrofitting your insulation, you can still spray in cellulose through holes cut from the interior or the exterior. To find out what insulation will work best in your home, you ll want to know the recommended insulation r-values in your area. R-value is the measure of a material s resistance to heat flow. The higher the value, the more effective it is. To see the recommended insulation r-values and cost estimates in your ZIP code, visit the Department of Energy s web site. Even a small draft can make your insulation less effective. Seal any gaps around electrical outlets, ducts, windows and doors with foam sealants, caulking or weatherstripping. The most important area to insulate is your attic. Make sure you ve got at least the attic floor insulated with blown-in or batt insulation to your area s recommended r-value, and consider insulating the roof and attic walls as well. This can provide a fully insulated buffer zone to keep heat where you want it and keep the lid on your energy costs. Find out more at BobVila.com: The ultimate home improvement web site! BobVila.com 2008