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2 Answers

Finishing insulation on unvented sloped roof with mineral wool over polystyrene

I have an unvented, sloped roof. I cut and cobbled 5 inches of expanded polystyrene into roof rafters, and 3 inches into attic wall studs. Then placed 2-6 inches of expanded polystyrene across the rafters and studs, to create a final air barrier and address thermal bridging.

I plan to cover the expanded polystyrene with 1 or 2 layers of Comfortboard IS mineral wool. Each layer is 2 inches thick. Expanded polystyrene seems ideal except for flammability, so I want to address that with mineral wool.

In General questions | Asked By Erich Riesenberg | Jan 18 15
1 Answer

Fixing a leaky basement duct chase/soffit run properly

I have a small, less than 1000sqft single story house with finished basement heated with a natural gas furnace.

The supply & return registers are on the floor of the main floor, so the ducts run under the floor joists.

Since the furnace room is in the back of the (rectangular) house, there's a soffit that travels to the front of the house, which runs perpendicular to the floor joists. This soffit contains both the main trunk supply and trunk return air ductwork that the registers branch off from. The soffit is enclosed with drywall & the ductwork is not visible.

In General questions | Asked By Jeff Watson | Jan 18 15
5 Answers

The off-grid solar community story was great -- I would love to know more about their insulating window shutters

The off-grid solar community story was great. I would love to know more about their insulating window shutters. Please have the author elaborate on this, as offered in the article.

Please, details on window insulating shutters. For a DIY, it's a great way to beef up privacy and efficiency. Thanks.

In Green building techniques | Asked By Scott Barkdoll | Jan 13 15
1 Answer

Rigid foam on an interior basement wall with exterior rigid foam present


In General questions | Asked By Milan Jurich | Jan 18 15
4 Answers

Foundation insulation transition to SIPs

Hi All-

I'm getting ready to build a couple of single family urban infill homes in Denver, Colorado (climate zone 5b). Local zoning creates a very narrow home (19' wide from exterior finishes) which has me leaning towards using PUR SIPs (4.5" or 6.5") for the exterior walls. The exterior finish will be limestone panels, making using exterior foam and strapping challenging due to the 14lbs per sq weight of the panels.

In Green building techniques | Asked By Christian Butler | Jan 17 15
10 Answers

What's a better stackup for R-value and moisture management for a cathedral ceiling?

I have a hand framed area between ganged room in attic trusses that I could potentially turn into a cathedral ceiling. The spacing between the gangled roof trusses is 10' and is hand framed with 2x6s running perpendicular to the top chord of the trusses. The 2x6s are attached with metal joist hangers that are attached to the top chord. (Think flush installed purlins). The finished ceiling material will be blue board gypsum and veneer plaster. The finished roofing is asphalt shingles over 15# felt with 5/8" plywood sheathing. Building location is climate zone 6, Green Bay, WI. Go Packers!

In Energy efficiency and durability | Asked By Rick Van Handel | Jan 13 15
3 Answers

Masonry heaters and U.S. building code?

From what I understand US codes require two walls of masonry. My question is can the outer wall requirement be met with " stuco", and if yes is there a minimum thickness? Apparently European codes allow "single wall masonry heaters.

In Building Code Questions | Asked By Jerry Liebler | Jan 16 15
2 Answers

Double glazing

I am replacing some glazing in home built units. Planning low E-argon. Looking for recommendations re alternatives to aluminum for the edge spacers of units. Minimum thickness of space between glass will be 3/8".

In Green products and materials | Asked By Doug Clayton | Jan 17 15
4 Answers

Installing foam board insulation over existing plaster walls.

Greetings all.

In General questions | Asked By R Stubing | Jan 14 15
3 Answers

What's the best strategy for saving energy in my unconditioned attic?

I'm in zone 5A and have 6" of insulation between the floor joists and no insulation between the roof rafters. The HVAC system and all its flex duct work are in the unconditioned attic. The building is a town house with 40" common walls running east west and the 18" roof ridge running north to south. There is eaves and ridge venting. The roof rafters are irregularly shaped: some are standard widths, others are not.

In Energy efficiency and durability | Asked By stuart brodsky | Jan 15 15
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