New Green Building Products

Every energy-efficient home needs a tight air barrier. Here are some products that might help: a cover for recessed cans, a caulk for polyethylene, and a handful of new housewraps

Posted on Sep 10 by Martin Holladay, GBA Advisor

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A cover for recessed can lights. The manufacturer of the Tenmat cover for recessed can lights has chosen to illustrate the product with one of the worst fiberglass-batt insulating jobs ever photographed. The Tenmat cover has been cut vertically to illustrate how it fits over the light fixture.

In this new-product roundup, I'll look at a cover for recessed can lights, a new caulk for polyethylene, and several new water-resistive barriers (WRBs) that promise better performance than Tyvek or Typar.

A fire-resistant hat for recessed can lights
A Delaware manufacturer named Tenmat is selling an airtight hat for recessed can lights. Tenmat light covers are made from mineral wool; according to the manufacturer, they are fire-resistant.

Tenmat covers are installed from the attic. After making a slit in the cover to accommodate the electrical cable, the cover is pushed down to the drywall ceiling. The cover should be glued to the drywall with canned foam or thermal caulk. Needless to say, the slit or hole made for the cable needs to be sealed with housewrap tape or canned foam.

Once the Tenmat covers are installed, the ceiling can be insulated with almost any type of insulation, including fiberglass batts, cellulose, or spray polyurethane foam.

Tenmat covers come in two sizes: "regular" (9 inches high and 14 inches wide) and "oversized" (10 3/4 inches high and 16 inches wide). Energy Federation Incorporated sells regular size Tenmat covers for $19.65 each.

Besides the high price, there's only one catch to Tenmat covers: the covers can only be used for recessed can fixtures equipped with CFL or LED bulbs. If a homeowner inserts an incandescent or halogen bulb in the fixture, it can overheat.

Dow Corning 758 caulk
Dow Corning has come out with a new caulk that sticks to a great variety of materials, including polyethylene.

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FOR MORE INFORMATION

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Cosella-Dörken Products
4655 Delta Way
Beamsville, Ontario L0R 1B4
Canada
Tel: 905-563-3255 or 888-433-5824
info@cosella-dorken.com

Dow Corning
P.O. Box 994
Midland, MI 48686-0994
800-248-2481

Henry Co.
909 North Sepulveda Boulevard
El Segundo, CA 90245
800-486-1278

Tenmat
23 Copper Drive
Newport, DE 19804
302-633-6600

VaproShield
915 26th Ave. NW, Suite C5
Gig Harbor, WA 98335
866-731-7663
sales@vaproshield.com

The new sealant, Dow Corning 758, is a silicone caulk that the manufacturer claims will stick to polyethylene, polypropylene, vinyl, polyolefin housewrap (for example, Typar), peel-and-stick flashing (including Vycor and Tyvek window flashing), and peel-and-stick membrane (including Ice and Water Shield). The broad range of materials to which it sticks makes the caulk particularly useful for window installation.

Dow Corning 759 is said to be a low-VOC product.

A warning to anyone seeking technical information from Dow Corning on this product: my repeated attempts to obtain answers to a few basic questions about 758 sealant were ignored by the company. If any GBA readers can provide further information, please post a comment below.

Delta-Fassade S
Did you ever wonder why housewrap manufacturers can't come up with a tougher product — something that doesn't rip away from nail heads or get damaged by ladders?

If you're tired of Tyvek and Typar, and willing to pay for something tougher, you might want to look at four housewraps from Cosella-Dörken Products.

In ascending order of price, Cosella-Dörken's tear-resistant weather-resistive barriers are Vent S, Delta-Foxx, Delta-Maxx, and Fassade S.

Rated at 69 perms, Vent S costs about 45 cents a square foot — roughly three or four times the price of Tyvek or Typar. Delta-Foxx (214 perms) is more permeable than Vent S, but also pricier — between 65 and 90 cents a square foot. In Europe, Delta-Foxx is used on roofs as well as walls.

At 14 perms, Delta-Maxx has a lower permeance than Cosella-Dörken's other WRBs. However, it has the greatest tear resistance.

If you need a WRB that can withstand a certain amount of UV exposure — for example, a WRB for use behind open-joint cladding systems — you can use Cosella-Dörken's top-of-the-line WRB, a product called Fassade S. Delta Fassade S (74 perms) costs between $1.10 and $1.20 a square foot.

Fasssade S has UV inhibitors that allow it to be installed behind unusual cladding systems — for example, a screen made of gapped boards that admit some sunlight. Gaps may be up to 2 inches wide. "Basically it is designed to be exposed to some sunlight throughout its life," said Peter Barrett, product manager.

Although it can withstand quite a bit of UV exposure, the manufacturer recommends that it be covered with cladding within 3 months of installation. Fassade S does not qualify as an air barrier.

To make sure that fastener penetrations are watertight, the manufacturer recommends the use of tape or a foam gasket between the WRB and any girt or strapping attached to the WRB.

Building scientist John Straube tested Fassade S by attaching it to the exterior of a small trailer. After driving the trailer for more than 6,000 miles, through snow and heat, he says that the housewrap "is still going strong.There was not a bit of deterioration or fraying that I could see in the wrap."

WrapShield SA
VaproShield is selling a self-adhered WRB called WrapShield SA. Although it's a peel-and-stick product, it's not a rubberized membrane; it's a vapor-permeable housewrap.

The fact that it is a self-adhered wrap gives it several advantages: since it's self-adhering, fewer fastener penetrations are required to install it; it doesn't flap in the wind or suffer from "wind pumping" problems; and it's very airtight.

In addition to being a WRB, WrapShield SA can be used as part of an air barrier system. According to the manufacturer, it sticks well to plywood, OSB, DensGlass sheathing, and concrete blocks. No primer is necessary.

WrapShield SA seals well around small fasteners, although larger fasteners like #12 or #14 screws might require sealing. WrapShield SA works well with a rainscreen application; the manufacturer also makes a vinyl batten called VaproBatten to complete the installation.

WrapShield SA is rated at 50 perms and costs between 82 and 95 cents per square foot.

Henry Blueskin VP
Henry Company, a manufacturer with plants in Ontario and El Segundo, Calif., also manufactures a self-adhered WRB, similar in many ways to WrapShield SA. Henry Company's product is called Blueskin VP.

Blueskin VP has a permeance of 29 perms. It needs to be applied at temperatures of 40°F or warmer. Like WrapShield SA, Blueskin VP has a peel-away paper backing; it can be adhered to a wide variety of substrates (including OSB, plywood, DensGlass, and concrete blocks) without fasteners. A primer must first be installed if the product is used over concrete or concrete blocks.

Last week's blog: "Using Rigid Foam As a Water-Resistive Barrier."

Tags: can light, caulk, housewrap, polyethylene, recessed can, sealant, water-resistive barrier, WRB

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Scott's Contracting
scottscontracting@gmail.com
http://www.stlouisrenewableenergy.blogspot.com
http://www.stlouisrenewableenergy.com
scotty@stlouisrenewableenergy.com

Sedalia, Missouri Insulation Manufacturer

Green Build Information, Sedalia, Missouri Insulation Manufacturer
Follow Up on Building a Green America

Foamglas – My New Favorite Insulation Material

An old insulation material, Foamglas, is back and offers some significant environmental and performance benefits over the insulation materials most commonly used below-grade.

Posted on Sep 7 by Alex Wilson

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Foamglas is impervious to moisture and termites, and unlike extruded polystyrene, doesn't contain brominated flame retardants or blowing agents that contribute to global warming

I spend a lot of time studying insulation--which is one of the most important components of any green home or commercial building. I have a new favorite. Foamglas® building insulation has been made by Pittsburgh Corning for many decades and is widely used in Europe. For the past decade or two, however, it has only been actively marketed in North America for industrial applications. (It's been listed in our GreenSpec Directory as an industrial insulation material for years.)
Now Foamglas is back. Axel Rebel was brought over from Europe a couple years ago to rekindle interest in the product for building insulation. As Pittsburgh Corning's vice president and general manager of the North American Building Division, he's likely to make that happen. I met Rebel at the Building Science Corporation Westford Symposium (a.k.a. Summer Camp) last month, and I've been getting more excited about the product since then, as I've studied the particulars.
What is Foamglas?
Foamglas is a cellular glass insulation material that's impervious to moisture, totally inert (no offgassing), resistant to insects and vermin, strong, and reasonably well-insulating (R-3.44 per inch). It can be used for insulating roofs, walls, and below-grade applications, including beneath slabs. It is produced in 18" x 24" dimensions, and in 1-1/2" to 6" thicknesses, in 1/2" increments. An asphalt-based sealant is used between the insulation boards during installation.
Foamglas is 100% glass—manufactured primarily from sand, limestone, and soda ash. (Virgin ingredients are used in the two North American factories—in Texas and Missouri—while up to 66% recycled glass could be used, and European product has significant recycled content.) These ingredients are melted into molten glass, which is cooled and crushed into a fine powder. The powdered glass is poured into molds and heated (below the melting point) in a "sintering" process that causes the particles to adhere to one another. Next, a small amount of finely ground carbon-black is added, and the material is heated in a "cellulation" process. Here, the carbon reacts with oxygen, creating carbon dioxide, which forms the insulating bubbles in the Foamglas. CO2 accounts for more than 99% of the gas in the cellular spaces, and it is permanently trapped there.
If you scratch a piece of Foamglas (your fingernail can cut into it), you will detect a slight rotten-egg smell from hydrogen sulfide. Iron sulfate is used in the manufacturing process, and a small amount of hydrogen sulfide is produced. You don't want to breathe a lot of hydrogen sulfide, but there's very little in Foamglas and it's locked tightly into the cellular glass—in fact, even after 30 years in place, scratching Foamglas produces the same smell. "It's proof that the cells are absolutely airtight," Rebel told me.
Features
I'm working on an in-depth product review for the October issue of Environmental Building News that will address the various performance properties and environmental attributes of Foamglas; I only touch on them here. Readers of my articles and blogs over the last few years know that I've been critical of certain insulation materials for the flame retardants, blowing agents, formaldehyde, and other chemicals contained in them. This is where Foamglas excels. There are no blowing agents that deplete ozone or contribute to global warming. There are no flame retardants or other additives needed to improve fire resistance.
As a 100% inorganic material, Foamglas is inert and fireproof. And it has enough compressive strength to be used under any concrete slab—an application where extruded polystyrene (XPS) currently dominates the market. It's better than XPS, because, in addition to the absence of those chemicals, Foamglas is totally impervious to moisture (vapor and liquid), does not support mold growth, blocks radon, and keeps out termites and rodents.
Cost and availability
Foamglas is significantly more expensive than the other insulation materials we use. The typical cost of Foamglas T4+ (the most common product for building insulation) is about $1.00 per board-foot, according to Rebel—roughly two-and-a-half times the cost of extruded polystyrene (XPS), which averages about $0.40 per board-foot. Rebel admits that if you're comparing insulation materials simply based on cost and insulation value, you're not going to choose Foamglas. "We have to add another value," he told me. That value can come from replacing other layers in the construction system (vapor retarders, moisture barriers, radon-control layers), from greater durability, from environmental attributes, and even from installing a thinner concrete slab. "We can reduce the thickness of the concrete slab, because Foamglas is so rigid," Rebel said. Foamglas becomes more cost-competitive if you factor in all of these issues.
Foamglas is manufactured at two U.S. factories (in Texas and Missouri) and can be shipped anywhere. Product is currently distributed through dozens of dealers that primarily market industrial Foamglas materials. Rebel told me that it's no problem to supply it for individual houses—though shipping may increase the cost and result in some delay. With Pittsburgh Corning looking to increase its presence in the building insulation market, and especially in green building, this could be a good time to try it out.
For more information, contact Pittsburgh Corning Corp. at 724-327-6100 or visit the company's U.S. website.
In addition to this Energy Solutions blog, Alex writes the weekly blog on BuildingGreen.com: Alex's Cool Product of the Week, which profiles an interesting new green building product each week. You can sign up to receive notices of these blogs by e-mail—enter your e-mail address in the upper right corner of any blog page.
Alex is founder of BuildingGreen, LLC and executive editor of Environmental Building News. To keep up with his latest articles and musings, you can sign up for his Twitter feed.

Tags: New construction, Foundation, Roofs, Board Insulation, Foundation and Load-Bearing Elements, Sheet Waterproofing

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Scott's Contracting
scottscontracting@gmail.com
http://stlouisrenewableenergy.blogspot.com
http://www.stlouisrenewableenergy.com

Green Home Appraisal Issues

Without realistic "comps" that properly value energy-saving features, obtaining a home loan may be difficult

Posted on Sep 7 by Scott Gibson

One possible solution: a "green" MLS. In a recent blog, Michael Chandler trumpeted the advantages of a "green" Multiple Listing Service that informs realtors, buyers, and appraisers of a home's green features.

Passive solar designs that include generous amounts of insulation can save homeowners a great deal of money in operating costs over the life of the house. But getting banks to approve loans that reflect somewhat higher construction costs can be a struggle, sometimes forcing builders to dial back their plans and deliver a less efficient house.

This dilemma was at the heart of a question from a green builder and the topic of this week's Q&A Spotlight.

Danny Kelly was trying to build a house that would qualify for a Gold or Emerald rating from the National Green Building Standard. It included upgraded insulation, high performance HVAC, a solar water heater, tight building envelope, and passive solar design — in other words, all the features you'd like to see in a house.

The rub was the appraiser who valued the house for loan purposes. "The appraiser and the bank said they do not give any extra 'credit' for green features," Kelly wrote. "One of the comps they used was over 25 years old, so not even on par with a code house from an energy code perspective... [The] bank does not seem interested in helping much either."

The trouble with finding 'comps'
In setting the value of a house for loan purposes, real estate appraisers conduct field inspections and also must find sales of similar houses in the same area. Those are called comparables, or comps.

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VIDEO: How To Sell Green Homes

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GREEN PRIMER

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What is Green Building?

Is It Really Cheaper to Live In A Green House?

Do Green Houses Cost More to Build Than Regular Houses?

What's Wrong With The Way Regular Houses Are Built?

Appraisers make adjustments in value based on the age, size, and condition of houses in the same area that have sold recently. It's part number-crunching and part intuition.

"Despite my strong personal feelings, most appraisers' hands are tied by comparable sales in your area," writes GreenCountryHomes, a licensed appraiser. "No green comps, no chance for a realistic appraisal."

GreenCountry says an "educated appraiser" gave him a $25,000 green adjustment on a $340,000 property last year, only to have it disallowed by the bank review appraiser.

Because comps in the community were so limited, GreenCountry's $315,000 appraisal was cut to $285,000 by the bank review appraiser and the buyers walked because they thought they were overpaying by $55,000.

"Green building, in many markets, is like the $1,000 bath faucet," GreenCountry says. "The appraiser gives you no extra value for the more expensive faucet that does the same job as the $75 faucet. They have no comparables to justify the market paying more."

Lower appraisal, lower standards
GBA advisor and builder Michael Chandler detailed the shortcomings of this system in a GBA post last year.

In his case, a customer was approved for a $400,000 home. Despite having a suitable lot and a design that fit his customer's budget, the bank appraiser would not approve the actual cost of construction.

Because the owners couldn't come up with any more cash, they had to drop the passive solar and solar hot water features, along with the spray foam insulation that Chandler had recommended. The owners could add a Jacuzzi or a home theater, Chandler complained, but not features that would improve energy efficiency.

"Part of the problem is that the appraisers get their data from a [Multiple Listing Service] that doesn't necessarily show them what green features are included in the homes that have been sold," Chandler wrote.

In a GBA column earlier this year, Richard Defendorf said that rules on finding comparables for appraisals can be a real problem.

"In some markets, a dearth of appraisers familiar with green construction — or perhaps even more critically, a scarcity of nearby listings with comparable green features — can frustrate prospective homebuyers and homeowners who wish to refinance," Defendorf wrote.

So how does this problem get fixed?
"Find another bank," says Robert Riversong. "Often local savings & loan institutions are both more in tune with the community and more open to different approaches."

Riversong says he had a client who successfully won a construction loan and a mortgage from an S&L for a super-insulated house even though it was built of rough-sawn lumber with a frost-protected foundation, no central heat and no flush toilet.

That's the power of a local bank that isn't hamstrung by rigid national policy.

David Meiland suggested consulting RESNET, the Residential Energy Services Network, and two offices in the U.S. Department of Housing and Urban Development.

In the long term, it will take more than the understanding of local banks to fix this problem. Changing appraisal rules to allow more realistic adjustments for utility savings, and educating real estate agents on the value of green buildings also would help.

That won't happen overnight.

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Scott's Contracting
scottscontracting@gmail.com
http://www.stlouisrenewableenergy.blogspot.com
http://www.stlouisrenewableenergy.com
scotty@stlouisrenewableenergy.com

Is That Plastic Container Safe?

By Diane Blahut, Woman's Day
Thu, Sep 02, 2010

Buzz up!481 votes

Our homes are full of plastic, and the kitchen is no exception. The problem: Chemicals in plastic containers and other kitchenware may leach into the foods or drinks that they're holding. Scientific evidence suggests that some of these chemicals may be harmful to people, especially infants and children.

The two best-studied offenders are bisphenol A (BPA) and phthalates. BPA mimics estrogen and has been shown to disrupt hormone and reproductive system function in animals. Research by the National Toxicology Program found a moderate level of concern about its "effects on the brain, behavior and prostate gland in fetuses, infants and children." Phthalates have been shown to disrupt the endocrine system and have led to malformations in the male reproductive system in animals. Studies in humans have found associations between high phthalate exposure and a variety of health concerns including low sperm quality, high waist circumference and insulin resistance.

Researchers are still debating whether phthalates and BPA actually cause these health problems and, if so, how much exposure is necessary to trigger them. While these issues are being figured out, some experts recommend taking a preventive approach: "Minimize contact of food with problematic plastics as a precautionary measure to protect your health," suggests Rolf Halden, PhD, adjunct associate professor of environmental health sciences at the Johns Hopkins Bloomberg School of Public Health. Here are six simple tips for reducing your exposure to the potentially harmful chemicals in plastics.

1. Know the code. Look on the bottom of your plastic to find the recycling symbol (a number between 1 and 7 enclosed in a triangle of arrows). The code indicates the type of plastic you are using and can give you important clues about safety. "We generally say 1, 2, 4 and 5 are considered to be the safest," says Sonya Lunder, senior analyst at the Environmental Working Group. Try to avoid using plastics with 3 or 6, as these leach chemicals that may be harmful. Number 7 is an "other" category that includes BPA-containing plastics called polycarbonates. These plastics, which you should avoid, will have the letters PC printed underneath the 7.

2. Reconsider the microwave. Heat can increase the rate at which chemicals like BPA leach from plastic. Containers labeled "microwave safe" have been tested by the Food and Drug Administration (FDA) and found to leach extremely small amounts, which the FDA has determined to be safe. However, some experts advise people to keep plastic out of the microwave altogether. "I don't microwave anything in plastic," says Lunder. "It's really easy and fast to put my food into a ceramic or glass container and heat it that way." And never put plastic wrap on top of your food in the microwave, since it can melt. Use wax paper or a paper towel instead.

3. Use it for its intended purpose. Plastics that are designed for single use should only be used once. "Plastic breaks down over time," Lunder explains. "Some aren't designed to withstand heating and cooling." Most plastics with recycling code number 1 are intended for single use, such as disposable water bottles. And that takeout container from six months ago? Toss it. In general they're fine for refrigerating leftovers, but aren't designed for heat exposure or long-term use.

4. Wash by hand. Only put plastics into the dishwasher if they have a dishwasher safe label. If you want to be extra-cautious, wash all plastics by hand or use only glass and ceramic plates and dishes. In the dishwasher, plastics are exposed to detergents and heat, which may accelerate the leaching of BPA from food containers.

5. Do not freeze. Only put plastics in the freezer if they have a freezer-safe label. Freezer temperatures can cause plastics to deteriorate, which increases the leaching of chemicals into the food when you take containers out of the freezer to thaw or reheat.

6. Don't panic. Cutting down on exposure to potentially harmful chemicals in plastics can benefit your health. But as Dr. Halden reminds us, "Many things in your life pose a much higher risk than exposure to plastics, such as smoking, poor diet and even driving a car."

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Scott's Contracting
scottscontracting@gmail.com
http://www.stlouisrenewableenergy.blogspot.com
http://www.stlouisrenewableenergy.com
scotty@stlouisrenewableenergy.com