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3 Answers

Hybrid vented and unvented roof/attic

I'm working on a small renovation to the second floor/attic of old house in climate zone 5. A gable roof with basic dormers on each side. In short, the finished ceiling will follow the pitched roof (cathedral style) for about half the length of the rafters and then transition to a flat ceiling beneath horizontal framing akin to rafter ties. This leaves a small triangular attic space above (enough room to crawl around, but not enough room to stand).

In Energy efficiency and durability | Asked By rob williams | Nov 5 14
11 Answers

Hydronic radiant: how do I evaluate H-E tank vs tankless systems?

Hello GBA forum,

In Mechanicals | Asked By Brian Gray | Nov 3 14
6 Answers

Exposed fastener metal roof vs. standing seam?

I'm reading Martin's awesome roofing primer: http://www.greenbuildingadvisor.com/blogs/dept/musings/martin-s-ten-rule...

And I came across something a little confusing to me: the preference of an exposed-fastener metal roofing over standing seam. I think I understand that an exposed fastener job is easier to install and therefore cheaper. But is that it?

In Energy efficiency and durability | Asked By Nathaniel G | Nov 4 14
4 Answers

Duct work

Hey guys
In a recent post (spray foam insulated homes) there was a picture of a hrv and distribution box showing the white round plastic duct work leaving the box. Why can't we use this type of duct work for our regular hvac duct work? I Would think this material would deliver air more efficiently than rectangular metal ducts. Installation would be easier as well.

Thanks for your help

In Mechanicals | Asked By russell berenson | Nov 4 14
2 Answers

Avoiding a ledge in a basement


Let me start by saying I am not a builder so pardon my explanation. I am located in Nova Scotia, Canada. I am looking to finish my basement and I want to avoid having the basement ledge I commonly see. We have a step down foundation so all of my walls have an above ground section that has been drywalled, vapor barriered, and has fibreglass insulation and a below grade section with exposed concrete. My contractor recommended building a wall in front of this so we could avoid the ledge.

In Green building techniques | Asked By Jason Keddy | Nov 4 14
7 Answers

Climate Zone 6: Low-slope warm roof materials / assembly

I am designing a large mono-pitch shed roof in Climate Z6. The slope is 1.5 in 12 or about 7 degrees. A ventilation space seems impossible due to the scale of this roof plane. 60 feet sloping up and about 25 feet wide. I would like the finished roofing to be standing seam metal as the roof is visible from various vantage points on the property.

It my understanding that we will need to install a high-temp waterproof membrane like Grace Ultra over the entire roof sheathing to prevents leaks. This means the roof assembly is only able to dry to the inside.

In Energy efficiency and durability | Asked By Meri Tepper | Oct 29 14
3 Answers

I am considering a double wall construction

I am planning to build a house in Charleston, SC (Hot -Humid Climate) and would like to get as close to Net Zero as possible. I think mini-splits will work but dont know if double wall construction is the way to go. Any help would be appreciated.

In Energy efficiency and durability | Asked By Rick Fetter | Oct 30 14
0 Answers

Attic insulation options

Hi all,

This is about my primary house attic space. At some point I am going to finish half of it off. Here is a pic of the space:

Basically when you get to the top of the stairs, what is in front of you is what will be finished. Where the HVAC is located will be left "attic storage". This will give me roughly a 20x20 space.

In General questions | Asked By Joe Watson | Nov 3 14
10 Answers

Paperless Home Design-Build

I don't know how many are aware that over the past decade or two the aircraft/auto and some other industries have gone to paperless (no blueprint) designs. The design is built and inspected to 3D datasets, or DMUs(Digital Mock-up Units), some of which, but not all, interface to CAM(Computer Aided Manufacturing), mainly auto-fastening, CNC machining, rapid prototype type operations.

In Plans Review | Asked By Terry Lee | Nov 2 14
3 Answers

Solar gain tradeoff?

While the topic of solar gain via south-facing windows recently
came up in the "Martin's PGH manifesto" thread, I'm not going
anywhere near that flamewar with this question even if it's
peripherally relevant. The question concerns how worthwhile
it actually is to open my reflective shades on a sunny winter
day, and/or if there's a critical-point outdoor temperature
where increased radiative/conductive loss going *out* would
be insufficiently balanced by solar energy coming *in* and

In Energy efficiency and durability | Asked By Hobbit _ | Nov 3 14
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