Home

May 13, 2008

Question: What are some ways of saving energy?

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 I get the required R-Value within this depth?

Todd writes from Middlefield, Connecticut: "My 1400 SF home has an open attic above the living space that I would like to use to create a cathedral ceilinged area and loft floor. I need at least an R-30 for this ceiling insulation, but my roof is framed with 2x8's at 12" O.C. Can I get the required R-Value within this depth with any of your products??"

Answer: The highest R-value we have to recommend for a 2x8 cathedral ceiling is Kraft-faced R-21. Owens Corning does not make a product that will yield an R 30 in a 2x8 cavity.

Question: Is there a 2" fiberglass batt?

Dan writes from Philadelphia, Pennsylvania: "I am renovating an old warehouse in Philadelphia, and covering the brick walls with framing and drywall so that I can insulate them. The framing is 2x6's, so I can get R-19 fiberglass insulation between the studs, and as suggested by an architect, I'm leaving 2" for rigid insulation. Seeing how much rigid insulation costs, and noting that I am covering about 3,000 square feet of wall area, I am moved to seek out an alternate to the rigid insulation to fill this space. I think compressing 3 1/2" fiberglass insulation into the space won't help, but is there a good solution with fiberglass? For instance, if there is a 2" fiberglass batt, what would the r-value be?"

Answer: Owens Corning insulation products are either fiberglass or extruded foam. I don't know of a suitable alternative. Two inches of Fiberglas™ insulation is approximately R-8.

May 12, 2008

Question: Can I add rolled insulation over loosefill insulation?

Theresa writes from Louisville, Kentucky: "I have loose insulation (blown-in?) in my attic. Can I add rolled insulation over the loose insulation?"

Answer: Yes, you can add rolled insulation on top of loosefill insulation. If the existing blown-in insulation fills the floor joists, we recommend running the new unfaced insulation perpendicular to the direction of the floor joists. If the existing insulation does not fill the joists, place the new insulation between the joists.

Question: How should I insulate an attic that has blown fiberglass and no vapor retarder?

Johnny writes from Albuquerque, New Mexico: "My house is about 65 years old. I have 2x6s in the attic with 3" to 5" of blown fiberglass, no vapor barrier at all. All inside ceilings are plasterboard (sort of a cross between plaster and drywall? I forgot the trade name some time ago), with many layers of latex paint over that, I'm sure. I have 3 passive gable vents maybe 20"x15" each for ~1200sqft of attic. No eave or peak vents at all.

I'd like to add insulation, and I've read arguments for and against kraft faced batts with regard to moisture retention, etc. So, put new fiberglass with kraft facing under the old, or just fill up to the top of the 2x6s with unfaced and then put unfaced R30 over that, or take it all out and start over, or what? It seems to me that adding a lot of insulation, like I'm thinking of doing, causes more temperature differential and is more likely to condense moisture out of the hot air inside.

Also, I have a 2'-3' crawlspace under the house. The floor for the house is 2x6s again with no insulation. What to use there? There are small vents along the foundation into the crawlspace."

Answer: Provided the gable ventilation is adequate, you can fill the 2x6 cavity with unfaced insulation. Then place additional unfaced insulation on top, placing it perpendicular to the first layer.

May 09, 2008

Question: Is this what you are suggesting?

Lynne writes again from Clinton, Ohio and sends another drawing: "I am a little confused. Can you look at the attached and tell me if this is what you are suggesting? Can't really lay insulation on the floor behind the knee walls. This is used for storage and has a wood floor. Wouldn't picture 2 be better?"

Answer: Picture two is fine as long as you realize that you will now be heating the areas behind the knee walls. When you insulate, the general idea is to wrap the living spaces with insulation. Again be sure to maintain 1" ventilation under the entire roof deck.

May 08, 2008

Question: Will I trap moisture behind the foam?

Trip writes from West Hurley, New York: "If I add rigid foam to outside of kneewall behind our upstairs bedrooms, with existing fiberglass batt insulation with kraft paper facing in, will I create any moisture problems by trapping moisture behind the foam? Any other consideration I should account for?"

Answer: FOAMULAR® extruded foam insulation is not a vapor retarder. It is considered breathable. It has a closed-cell construction that does not let liquid water through but it will allow water vapor to pass through. If the back side of the knee wall is exposed to living space it would need to be covered with drywall. But it doesn't sound like it is so there are no other considerations.

Question: Should we leave an air space above?

Lynne writes again from Clinton, Ohio and sends a drawing: "Here is what the room looks like in comparison to the roof. There are knee walls with storage areas behind them."

Answer: A minimum of R-38 is recommended in the ceiling of the room you are insulating, with R-13 on the knee walls. Install more R-38 on the floor behind the knee walls. Be sure to maintain at least one inch of airflow along the entire roof line. The ceilings behind the knee walls do not need to be insulated.

May 07, 2008

Question: Can I install a radiant barrier with insulation?

James writes from Round Rock, Texas: "I am finishing a small attic space (not the "main" attic. I have 2x6 rafters and want to get as much insulation as possible without having to build them out. My question is as follows: Can I install a radiant barrier directly to the roof decking between the rafters, then install R19 and then install foam board over that before adding the sheetrock. Will there be enough space for air flow? Does the radiant barrier have any impact?"

Answer: Fiberglas™ R-19 insulation is 6-1/4" and will fill that 5-1/2" cavity and more. There will be no space for the recommended 1" airspace under the roof deck. Owens Corning does not manufacture radiant barriers, and has no recommendations related to their use. You may want to contact a company that produces them to find out more about their use.

Question: Is there a facing to place over the new insulation so it doesn't get in my hair?

Nachum writes from Elmer, New Jersey: "Paper faced Insulation in the attic was installed about 1940. IT is falling down and I want to put new insulation over the old. Your information advises to use unfaced insulation and run it perpendicular to the existing. The attic has low head clearance and our head will rub against the new material. I prefer not to remove the old stuff. Is there a recommended facing to place over the new so it doesn't get in my hair?"

Answer: Hmmm. If your attic is unfinished and not conditioned (heated and/or cooled), the insulation should be on the floor and not overhead. In such an attic there should also be ventilation to help remove any moist air that enters the attic and keep the roof deck dry. When we recommend adding new insulation in a perpendicular direction, we are expecting it will go on the floor. If the attic space is conditioned, the insulation can go overhead if there is ventilation between the insulation and the roof deck. In this case the insulation should have a vapor retarder and it should be on the warm-in-winter side, which in your case would be the inside of the attic. And if that’s the case, the Kraft paper facing needs to be covered with a 15-minute thermal barrier such as drywall. If you want to discuss your situation to fully understand our recommendations, call the helpful Owens Corning customer service folks at 1-800-GET-PINK (438 7465).

May 06, 2008

Question: What is the best way to insulate the unfinished ceiling of my garage?

Jeff writes from Windsor, Wisconsin: "What is the best way to insulate the unfinished ceiling of my garage that is attached to my house? The garage walls are insulated and drywalled. I use the attic area of my garage for storage and have access by means of a drop down ladder. Can I use faced insulation stapled between the ceiling joists?"

Answer: You may not need insulation in the garage ceiling if both the garage and the space above it are not conditioned (heated and/or cooled). Thermal insulation will be helpful if there is living space above the garage but you say that space is only used for storage. For storage areas above garages there is typically ventilation and insulation in any walls that are shared with the living space of the home. Insulating the ceiling and walls of an un-conditioned garage can create a "hot box" situation where daytime and vehicle heat are retained in the summer and not allowed to dissipate.

Question: How should I install insulation in the basement?

Shenika writes from Philadelphia, Pennsylvania: "I wanna do a back basement room it has a lot of paneling missing and the walls are cement and it's freezing cold in that room do I have to put the insulation up over the cement wall and if there are big plumbing pipes do I cover them as well or cut around them and then do I secure the insulation with nails then put up the dry wall over it and can I paint the dry wall? As you can tell this is my first time doing this but I just wanna be sure especially about the insulation because my bedroom is also located in the basement near this room."

Answer: What you describe seems good. You don't mention what you will be framing with. Will it be wood? The best thing would be to insulate the pipes first and then insulate between the studs with fiberglass. Use faced insulation if you are insulating exterior walls. The paper goes toward the warm-in-winter side, which is the interior side. The studs can then be covered with drywall and painted. Moisture-resistant nails or staples should be used to secure the insulation.

May 05, 2008

Question: Should we apply insulation at the entire roof eave to peak or over the ceiling leaving an air space above?

Lynne writes from Clinton, Ohio: "I have a 1939 cape cod style home in Ohio. We are in the middle of removing all of the drywall and old insulation from the attic/upstairs and plan to convert the space into a bedroom and bathroom. We plan to spray on Sherwin Williams eBarrier reflective paint on the underside of the wood roof then leave 2 inches of space then reinstall insulation underneath with the vapor barrier facing the room. I read that we should install R-33. How thick is that? I was wondering if we would have to fur out the rafters. Should we apply insulation at the entire roof eave to peak or over the ceiling leaving an air space above with ventilation? The structure has knee walls and a ceiling. I was thinking that an unheated space above the ceiling would connect with the space between the roof and insulation so that air could circulate. No one seems to have the same idea about the correct way to insulate this attic! I can email a sketch if I haven't made myself understood."

Answer: Please email your drawing to be sure so we are on the same page. Owens Corning does not manufacture fiberglass insulation in R-33. The company makes an R-38 product that is 12 inches thick. That is the highest insulation R-value the company makes.

Question: Can I put insulation on the plywood flooring?

Frank writes from Woodstock, Illinois: "I want to increase the insulation in my attic to meet US government EnergyStar recommended R-values. I currently have fiberglass batts between the joists. A makeshift floor of 1/4" plywood has been overlaid and secured to the joists in some sections of the attic in order to facilitate movement and storage. When adding new fiberglass batts, do I need to remove the plywood "flooring" or can I lay the new insulation directly atop the plywood?"

Answer: If the insulation fills the joist, then unfaced insulation can be placed on top of the plywood flooring. If not, the new insulation will not be as effective.

May 03, 2008

Question: What could be causing the temperature difference?

Richard writes from Matthews, North Carolina: "I measured the indoor temperature inside my house at ceiling height and at the floor level and came up with a temperature differential of approx 6 degrees F. I believe that my attic insulation is adequate. There is old R-11 insulation under the floor in the crawl space that has a paper vapor barrier on the side facing the floor and a thin clear plastic covering on the side facing the crawl space. It is sagging badly and needs to be re-supported. Could this be the cause of the temperature difference? Should I replace it or just supplement the existing with additional unfaced insulation? What R-value should I use in either case? Should I use batts or continuous strips?"

Answer: Yes, sagging insulation could be the cause of heat loss through the floor. The U.S. Department of Energy recommends a minimum of R-19 be used under a floor. Unfaced insulation can be added to what is there. But if there is plastic attached to the bottom of the floor joist, remove it and use it to cover the floor if it is dirt. Putting it under the insulation may cause moisture issues.

Question: Will I have a moisture issue due to a lack of ventilation?

Bob writes again from Sunnyvale, California: "I knew the R-values were cumulative, but I was concerned about the moisture issue. Sunnyvale CA is not a very humid area, and I didn't know if having only a 1/4 inch gap between the insulation and the plywood attic floor would cause moisture issues due to a lack of ventilation. Based on your response, you think the moisture issue will be OK if the 2nd R-15 layer is unfaced. Is this correct?

Given that 2 R-15 layers is only 7 inches thick, why doesn't Owens Corning put out an R-30 insulation product that is only 7 inches thick? Standard R-30 is 9.5 inches thick and R-30c is 8.25 inches thick."

Answer: Yes, unfaced insulation is what we recommend. Regarding your second question, Fiberglas™ R-15 insulation is a higher-density product made for 2x4 walls where space is limited. It is a more expensive product to make. Standard R-30 insulation is generally used in unfinished attics where space is not restricted. R-30c is made for cathedral ceilings where some space limitations exist. Bottom line: deciding what thicknesses and R-values to make comes after weighing a variety of factors including what the market needs, wants and is willing to pay for.

May 01, 2008

Question: Should I remove the facing where it contacts the top plate and trusses?

David writes from Highland, Michigan: "I just insulated my addition, R38 in the ceiling, inside pitch 2.5/12 outside pitch 5/12 with a 2" spacer for insulation space. I have the attic baffles. I pushed the insulation to the outer edge of the wall's top plate. Where the Kraft paper contacts the top plate and trusses, it does not sit nicely due to the slight bend. Cold air easily comes through at the corners. I'm thinking about removing the paper where it contacts the top plate and trusses so insul can expand into the corners. Maybe remove the paper an inch from the inside wall surface. See any issues? I should not need the paper on top of the wall, outside of the interior air space."

Answer: I see no issue with that if the vapor retarder covers the ceiling below.

Question: What should I do if the attic already has faced insulation?

Bruce writes from Pine Plains, New York: "I purchased R38 $500.00 of faced insulation from Lowe's in Kingston New York, the contractor tech in the store advised me it was OK to use the faced insulation on top of the beams and insulation that was there already. This did not seam correct but he stated that was OK to do. After I started this project I felt this was wrong! I search for information and found in Owens Corning energy saving paper work it states…. (USE UNFACED OVER ADDING TO EXISTING INSULATION IN THE ATTIC). What do I do NOW?????"

Answer: As you accurately noted, when insulating on top of existing insulation we recommend using unfaced insulation so no vapor retarder will be on top of the original insulation. However, insulation with a vapor retarder can be placed up to one-third of the total thermal resistance in the assembly starting from the warm side. If the insulation you are adding has at least twice the R-value of the insulation already in place, then it should work. The other options are to remove the vapor retarder from the new insulation you will be placing on top of the existing insulation (messy and not really recommended) or freely slashing the new vapor retarder with a utility knife.

April 30, 2008

Question: Do you still make insulation covered with plastic?

Margie writes from Riverside, New Jersey: "Do you still make the insulation pieces that were 16 in by 24 in and covered by plastic so they were mold resistant? If so, who sells them? If not, is there any thing comparable?"

Answer: This sounds like a description of MiraFlex multi-project insulation which was discontinued several years ago. Owens Corning no longer makes fully encapsulated insulation products. A product to consider is Owens Corning PINKPLUS® insulation available at Lowe's. It is not fully encapsulated but it is faced on one side and covered with fabric on the back side.

Question: Is it dangerous for my daughter to breathe this?

Gerri writes from Freehold, New Jersey: "My husband took 2nd floor ceiling out 6 years ago, was planning to make a very tall second floor, we have a small thin hallway 6x 20 feet. with attic space on both sides on top and bedrooms on both sides 2nd flr level, my question is, 6 years ago he put up 2x4 wall to rafters on both sides of hallway. With insulation bought at home depot. It has torn and been exposed since then; it has shiny paper i think its fiberglass. My daughter's bedroom door opens up to this space she's 3 years old son is 18 is it dangerous for her to be breathing this in? Want hubby to complete this project."

Answer: I can't help with getting your husband to complete the project but I can tell you there is no long term health risk in the situation you describe. There is a possibility of irritation if the insulation is handled. That irritation is a mechanical abrasion caused by the ends of the fibers scratching the skin. This is not an allergic reaction and the itching generally subsides when the source of the irritation is removed by washing it off.

The few fibers that are small enough to become airborne and breathed into the lungs will be removed as fast as the ordinary dust we breathe every day. They simply don't stay in the body long enough to cause disease.

Based on more than 60 years of research, we believe our glass fibers are safe to manufacture and use. When working with the material we recommend following industry safe work practices to avoid irritation.

April 29, 2008

Question: Can I use two layers of R-15 insulation for R-30?

Bob writes from Sunnyvale, California: "I have 2x8 rafters (7.25" space) and need R-30 insulation in my ceiling to meet code. I would like to put a plywood floor down on top of the rafters to make my attic space usable. Can I use 2 layers of R-15 insulation (each 3.5" deep) to achieve the total R-30 insulation? This would leave only 0.25" of clearance between the insulation and the attic plywood floor. Note, the attic ceiling will only be 5'11" high, and I'm trying to prevent losing any walking room by raising the floor."

Answer: As long as the insulation is not compressed, Fiberglas™insulation can be layered and the listed R-values are cumulative. In your case, two R-15 layers will equal R-30. Just be sure that the second layer of R-15 is unfaced to avoid moisture issues.

Question: How does R-21 at 5.5 inches have better insulating value than R-19 at 6.5?

Dave writes from Waterbury, Vermont: "I plan to finish an attic space with 2 x 6 ceiling joists. I planned to install your r21 kraft faced pink insulation, before wall board. On your website it appears the best application is the r21 at 5 1/2 deep and 16 inches wide. However, the building supply stores I have been to say compressing r-19 down to 5 1/2 isn't a big deal (contrary to your web site) AND that it will take months to order r21, so two questions: 1) How is r21 at 5.5 have better insulating value than r19 at 6.5? 2) Assuming r21 is the best, how do I get it in Vermont?"

Answer: How do we increase the resistance to heat flow in the same or less thickness? One way is to increase the number of fibers to reduce the size of the pockets of trapped air that resist convection. This is what happens with the insulation for a 3-1/2 inch wall going from R-13 to R-15. The amount of glass in the wall is increased in the same overall volume, which increases the density and hence the R-value.

Another way is to add a gas that has a lower density, which reduces the convection in the air pockets. This is not practical in fiberglass but can be done in foam by making it with a lower-density blowing agent.

R-21 and most other high density fiberglass insulation products are available as a special order from local retailers. Here are a few you can try:

Noyes & Noyes, Inc.
Middlesex Road
Waterbury, VT 05676
802-244-6387

STATION LUMBER AND HARDWARE
15 RAILROAD ST
WATERBURY, VT 05676
802-244-8532

Morrisville T.V. Lumber
Route 100, Sylvan Park Road
Stowe, VT 05672
802-253-8516

April 28, 2008

Question: Do you have a foam roofing product?

Jennifer writes again from Saginaw, Michigan: "It has a flat metal roof and no attic access. We found something called Iso-board. Do you have anything like that?"

Answer: Owens Corning manufactures FOAMULAR™ extruded polystyrene insulation. This is a PINK rigid foam board product that provides an R-value of five per inch. Among the major benefits of the product are compressive strength and resistance to moisture. The term you heard is probably shorthand for polyisocyanurate, another type of insulation that Owens Corning does not make. I recommend contacting a contractor to find out if FOAMULAR insulation is suitable for your particular application. If you want to learn more about FOAMULAR insulation online, you can find it on the Owens Corning website.

Question: What do you recommend for our local fire department?

Jennifer writes from Saginaw, Michigan: "We're doing a research project for FIRST Lego League and we need to know what type of insulation to recommend to our local fire department who doesn't have any insulation on their roof or ceiling. What would you recommend?"

Answer: We recommend PINK insulation (because Owens Corning has a trademark on the color PINK when used with building insulation and is therefore the only company that can make and market PINK insulation). To go beyond that and be seriously helpful, we need to know more about the building you plan to insulate. Does it have a flat or pitched roof? Is there an attic you can access? Anything you can tell me about the fire department building will let me be more helpful in my answer.

April 26, 2008

Question: Where can I get the best price for insulation?

Chuck writes from Bremerton, Washington: "WHERE CAN I GET THE BEST PRICE FOR 850 SQ FT OF R49 INSULATION FOR MY HOUSE? I PREFER PINK PANTHER. WHAT KIND OF COST PER ROLL? PLEASE ADVISE." Answer: Owens Corning is the manufacturer of PINK Fiberglas and FOAMULAR insulation but the company does not set retail pricing. Here is a list of insulation dealers in your Zip Code area:

Lowe's 1534
5600 State Highway 303 NE
Bremerton, WA 98311
360-405-6270

James Lumber & Ace Hardware
19801 Viking Ave N
Poulsbo, WA 98370
360-779-5571

Alki Lumber and Hardware
4422 36th Ave SW
Seattle, WA 98116
206-932-7700

Limback Lumber Co
2600 Market St
Seattle, WA 98107
206-782-3487

Other insulation retailers and Owens Corning Certified Energy Professional® installers can be found through the company’s Web site based on ZIP Code.

At the home page, select Owens Corning Building Materials and Services. Click on the button labeled Find a Building Professional. Enter your ZIP Code and select the words that describe your project. Another click or so and you will have the option of selecting retailers or contractors. Click here for a shortcut to the Locator page.

Question: How should I insulate my three-season sun room?

Tom writes from Portsmouth, New Hampshire: "We are adding a sunroom / 3 season room to our house. It will be unheated, but it faces South so it will heat up when sunny. It is full of windows and sliding doors and it is wood frame construction with plywood/tyvex/cedar clapboard siding. "I have two insulating questions: "The roof is 2 x 8 construction so I plan on using your raft-r-mate plus R-19 kraft faced to insulate the roof - unless you have a better option? "I have a 22 inch high knee wall on two sides of the room built with 2x4 construction. The spacing of the studs is not really even since it supports the windows. I'd like to get some of your rigid foam board - a few sheets of 2 Inch and 1.5 inch and cut some squares to fill the cavities with 3.5 inches of foam. How does that sound to you?"

Answer: Your first statement about using R-19 Kraft-faced Fiberglas™ insulation with the Raft-R-Mate attic rafter vents matches our recommendation. However, we recommend using R-13 Fiberglas insulation in the 2 x 4 studded knee wall instead of cutting FOAMULAR® insulation to fit between the studs. Cutting foam insulation tends to be labor intensive and it may be impossible to get a tight fit.

April 24, 2008

Question: Will adding plastic create a double vapor retarder?

Patrick writes from Wenonah, New Jersey: "I live in southern New Jersey and I am remodeling a kitchen in a house with cinder block walls. The original kitchen walls were uninsulated and were not properly framed. I am framing out the walls with 2x4's and plan to add insulation. Some people I have spoken with suggest placing a 6 mil plastic vapor barrier directly on the cinder block behind the 2x4's and then insulating the spaces between the studs with kraft faced bats (kraft facing towards interior). Will this approach trap moisture between the kraft facing and the plastic and create a "double vapor barrier" issue? Would is be a better idea to ditch the plastic barrier and simply apply the kraft faced bats as recommended (kraft facing towards the interior)?"

Answer: Thanks for doing your homework and reading my blog. I am pleased to know I am not doing all of this keyboard work for nothing. You are correct. You only need and want one vapor retarder and it should go toward the warm-in-winter side, which you will have with the Kraft facing on the inside toward the interior.

Question: What can we do to stop a condensation problem?

Delores writes from Waldron, Saskatchewan: "We have a problem with condensation on the ceilings along the north wall on each spot where there is a floor joist. This occurs when it is very cold like around 0 F. The attic has blown insulation and pink batts overtop. Other walls are OK. What can we do to stop the problem?"

Answer: Condensation of moisture in the indoor air will occur where warm air meets a cold surface. Although I do not have information on the exterior cladding or age of construction, it seems as if there is no air retarder continuity at the floor joist level. A weather barrier such as a housewrap needs to be wrapped at the joist level and connected to the indoor air/vapor retarder of the attic to insure an effective barrier against wind-driven cold air. In winter, the cold air will penetrate into the house walls and will cause condensation at leakage points, i.e. floor joists. The attached document will show you the area that probably needs to be addressed.

April 23, 2008

Question: How should we have insulated our sun room?

Susan writes from Whiting, Maine: "We live in downeast Maine. We turned our old, outdoor porch into a sunroom with a vaulted ceiling. We insulated with faced pink fiberglass. The walls are fine, but the ceiling keeps trapping moist air and then dripping late in the day...so we have not dared put up finished exterior (tongue & groove pine) ceiling. How should we have insulated? Foam board taped to the hilt? Plastic sheathing over the faced fiberglass? Ceiling/roof is not vented as it was an outdoor porch. There seems to be no one or clear answer, help please!"

Answer: This problem may be caused by the lack of roof ventilation. Please call the Owens Corning customer service department to discuss your situation in greater detail. The number is 1-800-Get Pink (438-7465).

Question: Where can I buy R-15 high density insulation?

John writes from Winchester, Massachusetts: "Where can I purchase R15c fiberglass insulation for 2x6 walls? Its not carried at my local home depot."

Answer: R15 high density insulation is not a stock item. However, it is available as a special order from most Home Depot stores.

April 22, 2008

Question: What should I do about a vapor retarder?

Lou writes from Douglassville, Pennsylvania: "I thought I understood how to properly place foam insulation and vapor retarder, but a few posts have me confused! I've read that plastic vapor retarder is not recommended in the basement because it is too strong for the amount of moisture. I have also read that rigid foam should not be used as a sole vapor retarder. So if i wanted to use rigid foam on the walls and the floor, as well as rolled insulation in between metal studs, what should I do about a vapor barrier? Should I use non-faced insulation, kraft faced insulation?"

Answer: FOAMULAR® insulation is not a vapor retarder. Although extruded foam insulation has the characteristics of a vapor barrier, it cannot solely act as one. If you have multiple products with vapor barrier characteristics, you need to place the strongest vapor barrier nearest the warm air.

For basement applications, thicker foam is generally used, such as 1.5 or 2" InsulPink® extruded basement wall insulation. Please check with your local building code for more information. There is also information on the Owens Corning Web site about InsulPink insulation and proper basement installation using an extruded polystyrene (XPS) insulation.

Also, you are correct; Owens Corning does not recommend using poly vapor retarders over its insulation products in a basement because the poly is too strong and can trap moisture.

Question: Does your batt insulation contain formaldehyde?

Daniel writes from Pacifica, California: "Does your batt insulations contain formaldehyde?"

Answer: The production of Owens Corning batt insulation does include the use of formaldehyde. From the time fiber glass insulation was invented manufacturers have used formaldehyde as a binder ingredient in the manufacturing process to help glue or "bind" the glass fibers together. The trace amounts of formaldehyde found in both traditional and so-called "formaldehyde-free" insulation do not present health concerns. Owens Corning fiberglass insulation is certified to be low emitting by GREENGUARD, an independent testing lab. You can find more information on their indoor air quality testing standards at www.greenguard.org. For more on the facts about formaldehyde and insulation, click here.

April 21, 2008

Question: Do the same inches apply to loosefill and batt insulation?

John writes from Williston, Vermont: "We have blown-in (loose) insulation in our attic that is about 6 to 8 inches thick. I am thinking this is not enough. You recommend about 15 inches of regular insulation on your web site "insulateyouratticnow.com". Do the same inches of insulation needed apply to loosefit type of insulation as it does to regular insulation?"

Answer: Additional inches of blown-in insulation maybe needed depending on the type used. I recommend contacting a contractor for more details.

Question: So it is be OK to put PINK extruded foam on the concrete floor?

Ed writes again from Middleton, Wisconsin: "Thanks for the reply. So it would be ok to lay T&G Pink Extruded on the concrete, then put T&G OSB/Plywood over that, and drill or drive anchors into the OSB/Plywood, through the foam and into the concrete? That wouldn't be too hard, and it would keep the floor thin - I might upgrade to 2 layers of foam!"

Answer: Perfect!

April 18, 2008

Question: How should I insulate the ceiling of my garage?

Reuben writes from Gorham, New Hampshire: "I'm insulating my 1.5 car garage, turning it into a woodshop. I can insulate the 2x4 walls with fiberglass and then screw on a 1" foil backed form board and the cover it all with sheetrock, as you've described elsewhere in your blog. For the ceiling I am considering options. Raise the collar ties a bit and install sheetrock or 1/2" plywood for ceilings, then adding 12-24" of fiberglass batts on top. Or I could insulate the rafters (2x6) with fiberglass and foam board and sheetrock it, in order to keep the ceiling as high and as open as possible. With the latter, what is your recommendation? With the former, is there an ideal amount of fiberglass in the ceiling? Garage is 22'x18'."

Answer: You may do either. Just be sure to use unfaced FIBERGLAS™ insulation with at least one inch of FOAMULAR™ extruded foam insulation. Or install Kraft-faced R-19 or R-21 between the 2x6 rafters. Kraft facing should be installed toward the warm-in-winter side.

Question: Should I remove existing insulation?

Joseph writes from Lynnfield, Massachusetts: "Looking to upgrade attic insulation. Current insulation has vapor barrier facing up - 3.5"/16 on ctr 8" deep. Should I remove existing insulation? What is the recommendation between R30C and R30. I have been informed to remove existing and install new insulation with barrier facing living are."

Answer: We recommend that the insulation be flipped over. Leaving it the way it is could lead to condensation collecting in the fiberglass insulation and damaging the surrounding framing. R30C is thinner than standard R30. It is used in cathedral ceilings, or were space is limited.

April 17, 2008

Question: Can I completely fill the crawl space with insulation?

Johnnie writes again from Steele, Missouri: "The problem is that the crawl space is so small. There are trenches to crawl through. The center of the house is 125 yrs. old. It has been added on to twice. The last addition was 125' across back 52 years ago. I was thinking completely filling crawl sp. under north bedroom (15' by 25") with blown insulation. I had a problem with black mold. It is taken care of. I don't want that to start again."

Answer: I would be a little leery about filling the space since my friends at Owens Corning do not have any experience with filling crawlspaces. A typical crawlspace application would have a vapor retarder up against the floor above, a poly sheet on the ground to keep moisture from coming up and ventilation to allow any that does to escape. What you propose will have none of those. We don't have any good recommendations for you, other than to insulate the exterior of the foundation with FOAMULAR® extruded foam insulation and then cover the foam with an appropriate exterior finish.

Question: Can I put insulation on the inside walls before adding drywall?

Lorraine writes from Marietta, Ohio: "I have a 1975 mobile home that I'm remodeling. I would like to put insulation panels on inside existing wall before drywalling. Is there any problem with this?"

Answer: We need to know a few more details before we can help. Please call my helpful friends in Owens Corning customer service at 1-800-GET-PINK (438 7465).

April 16, 2008

Question: Is this stuff toxic?

Ana writes from San Francisco, California: "I just went up to my dad's attic, where there are clumps of pink insulation all over the place, just lying about on the floor. I've always understood that that stuff was toxic, especially if not properly isolated from human contact. He goes up there frequently. He says it's been there since the house was built in the 70's or 80's. Is this stuff toxic? If so, how toxic, and how should it be cleaned up?"

Answer: There is no long term health risk in the situation you describe. There is a possibility of irritation if the insulation is handled. That irritation is a mechanical abrasion caused by the ends of the fibers scratching the skin. This is not an allergic reaction and the itching generally subsides when the source of the irritation is removed by washing it off.

The few fibers that are small enough to become airborne and breathed into the lungs will be removed as fast as the ordinary dust we breathe every day. They simply don't stay in the body long enough to cause disease.

Based on more than 60 years of research, we believe our glass fibers are safe to manufacture and use. When working with the material we recommend following industry safe work practices to avoid irritation.

If you want to remove it, my suggestion is to rake or sweep it up and bag it. Take your time and sweep or rake "gently" to minimize dust. To minimize the temporary skin irritation associated with fiberglass insulation, you should also wear a long sleeved shirt that is loose at the neck and wrists, long pants, gloves and a cap. Wear eye protection (safety goggles, safety glasses or a face shield or a combination of these, as appropriate). And wear a disposable dust respirator to minimize the inhalation of dust. When you finish the job, launder the clothes you wore separately and take a warm-water shower with soap. Most people report no problems when they follow these procedures.

Question: What is the deadline for Energy Act tax credits?

Al writes from Hainesport, New Jersey: "Will I be able to apply for, an