Save Energy

I refuse to keep silent any longer

Mon, 06 Oct 2008 10:02:01 -0500

After decades of quiet, I'm breaking my silence on October 9.

What could be so compelling to make me break my silence after all these years? I can't share that yet but I am busy preparing for the big event.

Do you think you know what's prompting me to break my silence? If you do, send your idea to Iwillbreakmysilence.owenscorningblog.com.

Because I want everyone to know I am about to break my silence, I am visiting neighborhoods around the country. So keep an eye out for me. If you spot me and want to play movie-star-chasing paparazzi, take a video or photo and send it to Iwillbreakmysilence.owenscorningblog.com. Good luck with that because I can be one fast cat. But I also love to be in pictures with people - just ask me!

To find out why I will break my silence, check back here on Thursday, Oct. 9.

Question: Do you have a product that I can use?

Mon, 06 Oct 2008 09:57:54 -0500

Don writes from Afton, Virginia: "I am building a new home that will have a conditioned crawl space. I plan to put rigid foam insulation on the interior crawl space wall (block). Per code the rigid foam insulation must be fire rated with an R-Value of 11. Do you have a product that I can use?"

Answer: We recommend using unfaced Fiberglas insulation in the walls of a heated crawlspace. Unfaced Fiberglas insulation is non combustible and doesn't need to be covered with a thermal barrier. Owens Corning manufactures FOAMULAR® extruded polystyrene but it is not recommended for this application because it must be covered with a thermal barrier.

To install the insulation, hang it from the top of the block wall as shown in photos on the company's website. The photos show an encapsulated product being installed by the principle is the same for unfaced insulation.

Question: Am I creating a situation where moisture can be trapped?

Mon, 06 Oct 2008 09:53:56 -0500

Tom writes from New Orleans, Louisiana: "I just bought a flooded house in new orleans. it is about 50-60 years old. during the gutting phase, the previous owners did some damage to the blackboard behind the brick attached to the outside of the 2x4 walls. I recently cut 1/2" foamular insulation board and installed it in between all of the studs against the remaining blackboard to prevent air leaks as well as forming a moisture barrier. I even caulked around all of the seams to make a tighter seal. Since the summers get very hot and humid (100% relative humidity), am I creating a situation where moisture can be trapped inside of the walls? I plan on using R-13 fiberglass batt insulation in the walls."

Answer: Because of the time-consuming cutting required and potential for air-leaking gaps, we don't recommend installing FOAMULAR® insulation between framing members. Half-inch FOAMULAR is not considered a vapor retarder. We recommend installing Kraft-faced Fiberglas™ insulation in exterior walls with the vapor retarder installed toward the warm-in-winter side of the wall. Considering the humidity in your area, we recommend consulting your local building code for additional information.

Question: Should I replace rock wool that got wet?

Mon, 06 Oct 2008 09:49:57 -0500

V writes again from somewhere in the world: "The insulation material i was referring to in my query was about Fibrous Rockwool lightly resin (2%) bonded matresses for Hot insulation of piping"

Answer: Thanks for the additional information. It doesn't change my original answer. Fibrous glass and rock wool insulations can dry out and retain their R value but the concern is whether the insulation was contaminated with dirt in the water. If that is the case there could be mold issues.

Question: What are some ways of saving energy?

Fri, 03 Oct 2008 12:15:47 -0500

Chelsea writes from somewhere in Canada: "What are some ways of saving energy?"

Answer: Good question. Important question! The one I am most familiar with is using insulation to keep heat from leaving your home during cold winter months, and from entering your home during hot summer months. Insulation works something like my fur, wrapping me in a PINK blanket that helps keep me comfortable in winter and summer. For information from my blog sponsor, check out www.insulateyouratticnow.com.

There are lots of online resources with information about other ways to save energy. For example, the website for the PowerHouse television show has a downloadable brochure titled 101 Easy Ways to Save Energy. You can also request a printed copy.

For government resources check out The Ministry of Energy for Ontario brochure titled Tips to Help You Conserve Energy and Save Money. You can download a copy in English and 12 other languages.

You might also enjoy the website of the Canadian Centre for Energy Information. The site has lots of information about energy as well as energy-saving ideas.

The U.S. Department of Energy has a fact sheet titled Easy Ways to Save Energy. And you can use Google to find a lot of other resources and information; just type in a few key words. I typed in your question and got more than 2 million links to information about saving energy. Include the word Canada if you want to focus on information from your home country. Have fun!

Question: Can we rent a regular insulation blower to use with Atticat® insulation?

Fri, 03 Oct 2008 12:12:53 -0500

James writes from Carrollton, Texas: "The local store has Atticat insulation and rents a blower. We want to use it on a building near Austin (about 120 miles away) where there are no stores that carry the Atticat system. Can we rent a regular insulation blower in Austin to use with Atticat insulation?"

Answer: Thanks for your interest in the AttiCat® expanding blown-in insulation system. I am sorry the system is not yet available at retail stores in the Austin area. Owens Corning expects it will be available there later this year. In the meantime, my friends at the company are making arrangements to have a machine available for your use in the Austin area. If you will send me your contact information I will have the company's insulation distributor there give you a call to work it out.

Question: What type of nail should I use with foam insulation?

Fri, 03 Oct 2008 12:09:49 -0500

Matthew writes from Saskatoon, Saskatchewan: "What type of nail should I use to install 2" thick rigid insulation to the exterior of my house?"

Answer: Two-inch-thick foam insulation can be fastened with 4-inch nails and with green plastic washers. They can be purchased at just about any retail hardware or building materials outlet. If you find the washers in other colors they may work as well but I like the green ones best with PINK insulation.

Question: Can the Kraft paper vapor retarder contact with the top of the IC rated Halo can light?

Thu, 02 Oct 2008 10:29:09 -0500

Howard writes from Portland, Oregon: "I have IC rated cans installed in a cathedral ceiling. The kraft-faced insulation is installed with the vapor barrier facing the room. Can the craft paper vapor barrier come into contact with the top of the IC Halo can light or should the paper be removed? It seems that the paper could become a fire hazard."

Answer: Operating temperature of the Kraft paper is 150 degrees F. It is very common for the paper vapor retarder to be down toward the warm-in-winter side of the insulation and thus in contact with IC-rated fixtures. The IC-rated fixture requires no special consideration.

For others who read this on the blog, insulation should always be placed three inches away from recessed lighting fixtures unless the fixture is marked "IC" (Insulated Ceiling). If insulation is placed over an unrated fixture it may cause the fixture to overheat and perhaps start a fire. This is also true for metal chimneys, gas water heater flues and other heat-producing devices. Always check with the manufacturer of the appliance if you are unsure about insulating around the device and its exhaust system.

Question: Will the PINKcap® attic stair insulator work if the opening is smaller than a drop down stair?

Thu, 02 Oct 2008 10:26:26 -0500

Chris writes from Aurora, Ohio: "My attic does not have drop down stairs. The hole is 4 x 4 with just a piece of ceiling inserted up inside the hole. We use a ladder to get into the attic area. Would the PINKcap attic stair insulator work for us if the hole size is smaller than a drop down stair?"

Answer: It should work well as long as the opening is not too small to pass the PINKCap® attic stair insulator through it because the insulator cannot be bent.

Question: About how much did this originally sell for?

Thu, 02 Oct 2008 10:22:36 -0500

Mac writes from Bethlehem, Pennsylvania: "I have a roll of miraflex that I bought some time ago and never got around to using. About how much did this originally sell for? It's r-13 to r-18 15 in wide 32 ft long, 40 sq ft."

Answer: Are you going to take it back to the store and ask for a refund? Or put it up for auction on Ebay? (Just kidding.) You would think a smart guy like me would know the answer to your question but the price of the product was never in any of the commercials I did for Miraflex insulation. The company stopped making the product several years ago and the people who were involved with it have moved on to other jobs inside and outside the company. I don't know where to go for such information. Even if I did know the suggested retail price it probably wouldn't be exactly what you paid for it because retailers are free to set their own prices. I would say it was probably a little more expensive that the same amount of standard insulation because it was encapsulated. Sorry I can't be more helpful.

Question: Any suggestions on cutting foam board?

Wed, 01 Oct 2008 10:25:00 -0500

Dave writes from Olga, Washington: "I am installing foam board inside a box truss system which will be enclosed by plywood and then sheetrock. It consists of a top cord beam, lower cord beam and then vertical and diagonal members. The top cord is about 3.5 feet above the bottom cord. My plan is to cut the insulation board with a circular saw and fine tooth blade as there will be triangular pieces. I also plan to cut the insulation board smaller than the cavity leaving at least 1/4" gap all around the edge so that I can put crack sealer type foam insulation as used around windows and doors to seal the edges. I will also put plastic sheeting over either the inside surface of the insulation and then the plywood and drywall, or over the plywood and then the drywall. Any suggestions and advise on cutting the foam board?"

Answer: This is a tough one. We do not have recommendations related to using FOAMULAR® insulation in this application. We typically don't recommend that FOAMULAR be cut to fit between framing members because it is a time-consuming process and there is a significant potential for gaps that could leak air around the insulation.

Question: What is the R-value of R-30 compressed to 7-1/2"?

Wed, 01 Oct 2008 10:20:09 -0500

Tom writes from La Jolla, California: "I have 2x8 ceiling joists. Is it better to stuff R-30 batts into it or go with 6 1/4" R-19 batts and leave a 1 1/4" gap? What is the effective R value of compressed (to 7 1/2") R-30? Location is 2 miles from Ocean. Temperature very mild (40-95F)"

Answer: We do not recommend compressing Fiberglas insulation. R-30 in a 7 1/4" cavity yields R-25. I do not have a number for 7-1/2" but it should be close to what I reported in the second sentence.

Fiber glass insulation works on the principle of trapped air pockets. By compressing fiber glass insulation, you decrease the amount of air trapped in the material. It is better to buy the product that fits in the space.

If you are insulating under an asphalt roof deck, we recommend a minimum 1" gap between the roof deck and the insulation.

Question: Do we have to replace insulation that is wet?

Wed, 01 Oct 2008 10:15:41 -0500

V writes from somewhere in the world: "Do we have to replace the resin bonded fibrous insulation that has become wet due to rains? Cladding was not done on time."

Answer: I don't know what type of fibrous insulation you are writing about but if it is fiberglass insulation it will dry out and retain its R-Value. The concern is whether the insulation was contaminated with dirt in the water. If that is the case there could be mold issues. Fiberglass won't support mold growth but the dirt that got on the insulation along with the water could do so.

Before covering the insulation a physical and visual inspection should be done to ensure the insulation is dry. If the insulation is wet, Owens Corning recommends that it be removed from the cavity space to ensure that the insulation and facing (if applicable) are completely dried. Drying time will vary depending on the wetness of the insulation, ambient air temperature and relative humidity. In the case of dirty or contaminated water entering the product, there is only one answer – replace it!

Question: What is this procedure called and is it effective?

Tue, 30 Sep 2008 10:55:11 -0500

Michelle writes from Spruce Grove, Alberta: "I recently witnessed a house having insulation added to the outside and being recovered. What is this procedure called and is it effective?"

Answer: Adding exterior insulating sheathing is an effective way to "warm up" your exterior walls. The foam sheathing helps keep the overall wall warmer in winter because thermal bridging (where the heat bypasses the wall cavity insulation and travels out through the wood or metal studs) is cancelled. It is also a recommended insulation practice in provincial building codes across Canada for energy efficiency. Look for provincial and federal renovation grants for adding insulation at www.ecoaction.gc.ca/homes.

Question: Do I need to add more vents?

Tue, 30 Sep 2008 10:52:12 -0500

James writes from Macomb, Michigan: "I recently installed R30 insulation (with-out vapor barrier) to my attic, which already had 6 or 7 inches of insulation (with the vapor barrier). I believe my attic is sufficiently ventilated, but I've now noticed a black mold that is on the outside overhang of the house. What could be causing this? Is there too much insulation now or do I need to add more vents?"

Answer: R-49 is a common value recommended by the Department of Energy so it is not likely that there is "too" much insulation. It is more likely that you will find the ventilation needs to be improved. The minimum ratio is 1/300, meaning one square foot of ventilation for every 300 square feet of attic space when you have the proper balance of ridge and soffit/eave vents. We recommend a ratio of 1/150. There is additional information on the Owens Corning website about ventilation.