Roofing

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Wolfe Island Passive: Ready for Roofing

With the insulation installed, the next step is to prepare for steel roofing and build a porch roof that can handle big snow loads

Posted on Jan 19 2017 by David Murakami Wood

Editor's note: David and Kayo Murakami Wood are building what they hope will be Ontario's first certified Passive HouseA residential building construction standard requiring very low levels of air leakage, very high levels of insulation, and windows with a very low U-factor. Developed in the early 1990s by Bo Adamson and Wolfgang Feist, the standard is now promoted by the Passivhaus Institut in Darmstadt, Germany. To meet the standard, a home must have an infiltration rate no greater than 0.60 AC/H @ 50 pascals, a maximum annual heating energy use of 15 kWh per square meter (4,755 Btu per square foot), a maximum annual cooling energy use of 15 kWh per square meter (1.39 kWh per square foot), and maximum source energy use for all purposes of 120 kWh per square meter (11.1 kWh per square foot). The standard recommends, but does not require, a maximum design heating load of 10 W per square meter and windows with a maximum U-factor of 0.14. The Passivhaus standard was developed for buildings in central and northern Europe; efforts are underway to clarify the best techniques to achieve the standard for buildings in hot climates. on Wolfe Island, the largest of the Thousand Islands on the St. Lawrence River. They are documenting their work at their blog, Wolfe Island Passive House. For a list of earlier posts in this series, see the sidebar below.


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Image Credits:

  1. All photos: David Murakami Wood

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Will This Roof Design Have Problems?

A homeowner questions his architect’s plans for a standing-seam metal roof

Posted on Jul 4 2016 by Scott Gibson

Planning a new house in Climate Zone 6, Chad Kotlarz is reviewing his architect's plans for the roof — and discovers he has a few misgivings.

The unvented roof will be framed with 2x12 rafters, sheathed with plywood and capped with standing-seam metal roofing. Closed-cell spray foam will insulate the rafter bays, and the interior of the cathedral ceiling will be finished with gypsum drywall. An exposed truss with a collar tie provides structural support.


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Image Credits:

  1. dunktanktechnician/ CC BY 2.0 / Flickr

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Solving a Roof Dilemma

A mix of pitched and flat roofs creates a risk for leaks

Posted on Jun 6 2016 by Scott Gibson

Joe B is building what he hopes will be a PassivhausA residential building construction standard requiring very low levels of air leakage, very high levels of insulation, and windows with a very low U-factor. Developed in the early 1990s by Bo Adamson and Wolfgang Feist, the standard is now promoted by the Passivhaus Institut in Darmstadt, Germany. To meet the standard, a home must have an infiltration rate no greater than 0.60 AC/H @ 50 pascals, a maximum annual heating energy use of 15 kWh per square meter (4,755 Btu per square foot), a maximum annual cooling energy use of 15 kWh per square meter (1.39 kWh per square foot), and maximum source energy use for all purposes of 120 kWh per square meter (11.1 kWh per square foot). The standard recommends, but does not require, a maximum design heating load of 10 W per square meter and windows with a maximum U-factor of 0.14. The Passivhaus standard was developed for buildings in central and northern Europe; efforts are underway to clarify the best techniques to achieve the standard for buildings in hot climates.-certified home in Port Washington, New York, a town on the north shore of Long Island in Climate Zone 4. The house is well underway, but Joe worries about the potential for trouble in a very complex roof design.


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Image Credits:

  1. Illustrations courtesy of Joe B

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Leak-Free Skylights

A peel-and-stick membrane under the flashing guarantees that the skylight won’t leak — ever

Posted on Jan 21 2016 by Mike Guertin
prime

I used to worry every time I installed a skylight. Even with the best installation detailing, I could still expect a storm to hit from just the right direction and drive water behind the flashing.

When I discovered peel-and-stick membranes, my worrying days ended. Now I follow a series of simple steps that hasn’t failed in more than 15 years’ worth of installations. The key to success is integrating the membrane and the flashings with the shingles to direct water back to the surface of the roof. Although the project shown here is a retrofit, I would flash it the same way on a new home.


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Image Credits:

  1. Charles Bickford

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Designing a Low-Slope Roof That Works

Metal roofing or EPDM? Insulation above or below the sheathing? Vented or unvented? An owner weighs all the options.

Posted on Nov 9 2015 by Scott Gibson

If only Kevin Hoene's choices for a new roof boiled down to a choice between an EPDM membrane and metal, his life would probably seem a whole lot simpler.

But Hoene, building a new home in Illinois and on the boundary between Climate Zones 4 and 5, will soon be weighing the pros and cons not only of different roof coverings, but also of what type of insulation to use, whether it should go above or below the roof sheathingMaterial, usually plywood or oriented strand board (OSB), but sometimes wooden boards, installed on the exterior of wall studs, rafters, or roof trusses; siding or roofing installed on the sheathing—sometimes over strapping to create a rainscreen. , and whether the roof should be vented or unvented. In other words, nothing seems off the table.


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Image Credits:

  1. RoofsPlus

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You May Like These Plastic Water Bottles

After use, these specially designed bottles are squashed flat and turned into roofing tiles

Posted on May 28 2015 by Scott Gibson

A Costa Rican businessman has developed a type of plastic water bottle that can be turned into a roofing tile when its empty instead of pitched in the trash or sent to a recycling center.

Donald Thomson worked for years to develop the idea after watching children squash plastic water bottles during a beach cleanup, an article in PlasticsNews said.


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Image Credits:

  1. Jim Johnson / PlasticNews

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Fresh Warnings on a Class of Common Chemicals

Scientists and health experts warn that a class of chemicals used in thousands of products may pose health risks

Posted on May 6 2015 by Scott Gibson

Products as diverse as pizza boxes, architectural membranes, certain paints, carpet treatments, and coatings for metal roofing contain a common type of chemical that is drawing fresh concern from a group of scientists, public health experts and others.

The New York Times reported that scientists are concerned about a class of chemicals called poly- and perfluoroalkyl substances (PFASs).


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Image Credits:

  1. Think Stock

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Where is This Water Coming From?

A homeowner with a standing-seam metal roof wonders why water drips from the soffit

Posted on Apr 13 2015 by Scott Gibson

Writing from Climate Zone 6, GBAGreenBuildingAdvisor.com reader David Metzger is looking for some advice about his standing-seam metal roof. More to the point, why is there water dripping from the soffit when the winter's accumulation of snow and ice starts to melt?


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Image Credits:

  1. David Metzger

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Martin’s Ten Rules of Roof Design

For the best performance, build a simple roof shape over a vented unconditioned attic

Posted on Dec 9 2011 by Martin Holladay

Lots of things can go wrong with roofs: bad flashing can cause leaks, a poorly designed valley can turn into a slow-moving glacier, and misplaced gutters can do more harm than good. Experienced roofers see a lot of stupid roofs.


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Image Credits:

  1. Image #1: Top: Ezioman; bottom: Geoffrey Wheeler
  2. Image #2: DB King
  3. Image #3: Martin Holladay
  4. Image #4: Jon Christman
  5. Image #5: Trulia Inc.
  6. Image #7: Trulia Inc.
  7. Image #8: J.P. Bush Homes
  8. Image #9: Martin Holladay
  9. Image #10: Martin Holladay
  10. Image #11: Allison Bailes
  11. Image #12: Fine Homebuilding

Guide to Roofs and Roofing

Roofs keep the weather out and conditioned air in

Green roofs are energy efficient and durable. A green roof should be structurally sound and should include long-lasting sheathing and roofing.

When choosing roofing, look for products that are manufactured with minimal environmental impact and excellent durability. And remember: performance and longevity depend on how well the products are installed.

Get the what, why, and how below:


Articles about roofs and roofing:

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