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10 Answers

Previous code for unvented cathederal ceiling insulation

Hey All,

Just curious if anyone knows the previous insulation codes for a low pitched, unvented cathederal ceiling.

My home was built in the 60s and I am finally getting around to insulating and finishing the garage with the above described roof. I know current code is r49 with at least r20 of spray foam for dew point and that's my only option. I just don't see how the rest of my house is all still ok since it was built/insulated way before spray foam existing. Now if I want to just fill the garage bags with roxul or cellulose I hear my roof will mold and collapse.

In Building Code Questions | Asked By Steve Gabrielidi | Nov 26 15
8 Answers

Adding foam board to ceiling rafters?


The rafters in my ceiling are only 2 x 6. Is it acceptable to lay polyiso sheets across the top of the rafters, or should I be concerned about the foam acting as a second vapor barrier? The fiberglass batts have a kraft liner facing the sheet rock.

If the answer to the above is yes, can I place the foam in between the rafters against the sheet rock under the fiberglass batts?


In Green building techniques | Asked By Donald Mendell | Nov 29 15
3 Answers

Visual dictionary for building terms/glossary?

I know there's a Glossary link in the upper right corner of the GBA website, but is there the equivalent of a visual dictionary for common building components? Ok, I know there are some out there (e.g., visual.merriam-webster.com/house/structure-house/frame.php), but is there a good one online that people have used, and is it possible to include a link to it from GBA? I don't always know the names of the building components (e.g., which part of a window is the stool?), and from other poster's questions I can tell that not everyone knows a rafter from a joist.


In General questions | Asked By andrew c | Nov 29 15
2 Answers

Masonry block wall: To seal or not to seal?

In preparation to insulating my renovation of a 1970s building's masonry block wall with 2" XPS foam board attached directly to the masonry block, should I paint the interior masonry block wall with a sealer like DRYLOK® Masonry Waterproofer or KILZ 2® LATEX Low VOC?

Right now there is a thin coat of cheap latex paint on the block wall.

Russ :-)

In General questions | Asked By Russell | Nov 29 15
2 Answers

Questions about insulating 1947 concrete block home in Florida

We purchased a house in Orlando that we plan using as a rental. It is a one story block home, about 850 square feet. As with most houses built here during that time period it had no insulation with the exception of some blown in cellulose in the attic. We have gutted the house and found that originally there was no furring strips and drywall on the inside of the exterior walls, they have been painted and wall papered a couple of times then someone furred them out and put up wood paneling.

In General questions | Asked By Nathan Vaughn | Nov 29 15
9 Answers

SIP walls insulating the floor joists

I'm attaching a picture posted by Insulspan, the SIP manufacturer we're getting a quote from. It shows the SIP wall on the edge of the basement wall with the floor joists on the inside edge, providing continuous insulation of the rim joist. Has anyone seen this done? I thought at least 4 inches of the floor joist had to rest on the basement wall to be structurally sound. I plan on using superior walls which are 10.25 in thick and 8.25 in SIPs.

In Energy efficiency and durability | Asked By Brian W | Nov 29 15
3 Answers

Source for rock wool batts in Albany, NY area?

I am interested in using Roxul or other rock wool peoduct in bith batt form and board form for my build in Saratoga County NY, near Albany. Is there anyone here that can recommend either or both a source and an installer in this area?

In Green products and materials | Asked By Joe | Nov 29 15
2 Answers

What is the most economical heat system for a 700 s.f. house with no furnace?

I have a relative who may have to give up her house due to illness/unemployment Her gas furnace went on the blink. To replace it would be $1800 +. What is the safest most economical method of heat to heat her 775 sf house. She closes off one room so actually 3 small rooms & a bath is what she would be heating. For now she is using an electric fireplace and two infrared heaters that are supposed to heat up to 1000 sf.
Thank you.

In Energy efficiency and durability | Asked By Ruby | Nov 30 15
1 Answer

Detail on a garage wall abutment to an exterior block wall

Hi there - been using this site for about a year. Just performed an energy retrofit where I ripped out the ceiling in the garage Redid the ducting system, fixed a lot of electrical that was wired incorrectly or unsafe, airsealed, put ithen put in two layers of 1/2" polyisocyanurate, covered with 1/2" drywall.

If you follow this link: http://www.greenbuildingadvisor.com/cad/detail/air-barrier-garage-band-j...

that is exactly the configuration i built to (I did not use furring strips like the detail calls out though).

In Green building techniques | Asked By Daniel | Nov 29 15
1 Answer

Green / Passive House Architects

Anyone know of a good source for good energy efficient / Passivehouse architects?

In Green building techniques | Asked By Peter L | Nov 30 15
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