Replies

1. 
   ohioandy | Jul 25, 2018 12:35pm | #1

   Josh, I'm jumping in on this question because I built a SIP house. There is absolutely no default in ANYTHING with green homes. You will find many of us here being quite opinionated about what is best, but there are huge variations in climate, budget, environmental and aesthetic philosophy, availability of materials, and many other factors. One thing about SIPs is that they require specialists in design, engineering, assembly, and all the other subtrades that may not exist within a thousand miles of you. SIPs represent a pathway for a relatively narrow set of circumstances (such as quick assembly to dry-in, interesting span possibilities for floors and ceilings...); but conventional stick building can usually provide a far easier and cheaper way to achieve the same thing. If there's any default at all, it would be conventional stick framing built to the 2015 IECC for your climate zone, which incorporates careful air sealing and continuous exterior insulation. Start with that. Most folks struggle to find a contractor even willing to take that on.

2. 
   Andrew_C | Jul 25, 2018 01:08pm | #2

   Fighting words -
   Is this click bait, or are you just trying to start a fight? ;) I agree with Andy's response in 1). But he was polite and logical and speaking from experience, so here's an opinion - the de facto starting point for single family residences should be use exterior insulation and avoid cathedral ceilings. And limit air leakage to <1.0 ACH50. If you read through the Q&A here about all the tales of woe wrt cathedral ceilings and SIPs, I can't see any other conclusion than that those are high risk options that should be eliminated at the design stage.

3. 
   ohioandy | Jul 25, 2018 01:29pm | #3

   Whoa, Andrew, you wanna step outside and say that? In defense of SIPs, I can only argue that those tales of woe are universally the result of incompetent assembly. I have never read such a tale that acknowledged the failed SIP structure was assembled according to the incredibly clear instructions of the manufacturer and the industry literature. In the parlance of green building, though, SIPs represent a relatively high risk for failure due to water or vapor degradation; there isn't much innate resiliency. That has to be overlayed meticulously. I write this with 7 tons of slate roof over my head bearing on nothing but a few vertical sheets of 1/2" OSB :-)

   So yeah, Josh. SiPs are a lot of things--the continuous insulation is fantastic--but it's not a default for green homes unless you're a meticulous nerd.

4. GBA Editor
   Martin Holladay | Jul 25, 2018 01:48pm | #4

   Josh,
   There's lots of evidence that cold-climate SIP roofs have been failing due to air-sealing problems at the seams. These failures are difficult to fix. One such story was published on GBA; here is the link: "A SIP Roof Repair in Wisconsin."

   If you're talking about walls, not roofs, you may want to read this article: "How to Design a Wall."

5. 
   jackofalltrades777 | Jul 25, 2018 03:45pm | #5

   Like others have stated, there is NO default building material, except for maybe stick frame here in the USA. If you went to the MIddle East and places like Israel, the DEFAULT would be concrete/masonry construction. Wood is only used on the interior or for decoration purposes.

   You can find contractors on every corner who can do stick frame. SIPs like ICF, is a specialty that will limit you to maybe 2 or 3 contractors out of 1,000's that do stick frame.

   For me, this is my list of how to pick a methodology to construction:
   1 - What climate zone are you building in?
   2 - What environmental factors are you dealing with? (earthquakes, wildfires, tornadoes, termites, hurricanes, flooding, etc)
   3 - What is your budget?
   4 - What is your end goal to building this home? (flip, long term, retirement, etc)
   5 - How much maintenance do you want to deal with over the life of living in the home?

   Once you answer the above, then the question can be answered of what building method you will end up choosing. Then you have to ask yourself it there are qualified contractors that can build with the methodology you choose?

   For me, the above questions and subsequent answer led me to ICF walls and a SIP roof. When done CORRECTLY, following the advice of experts here on GBA and elsewhere, you can build a SIP roof or home and not have the disasters that some experience. If you chose a SIP home, I would definitely go with CLOSED CELL urethane foam which doesn't pose the same problems as open cell EPS foam. Plus closed cell urethane is fire resistant.

   Just as a sidenote: My roof SIPS (closed cell) were T&G panel joints with a rubber seal, I taped all interior and exterior panel joints with SIGA tape, I then added a breathable roof membrane and elevated the metal roof decking. Five layers of protection to make sure that I don't have problems. (Zone 4B)