I don't think any hard and fast rules can apply to this discussion.

When I was raising my first timber frame (my house), my friend said wait, you're going to build a whole separate wall outside of the frame? The only way it can make sense is to justify it in terms of the whole open building concept, that the structure is distinct from the enclosure. And I do like that concept, in theory at least. So unless we all build uninsulated barns we've got to deal with insulation somehow.

I've tried infilling between studs, a whole separate wall outside the frame, my very first SIP roof, DIY SIPS with rigid foam, and I've seen and done lots of research on stray/clay or woodchip/clay walls.

There's pluses and minuses and factors to be considered on all of these systems. I've come up with all sorts of design questions in trying to insulate spaces including (but not at all limited to):

-what is really local? Are the SIPS made 100 miles away local? The cellulose from local newspapers with studs from Siberia? How about studs sawn from the site? What if you then sheath it with plywood? Clay from the site? They don't grow much straw in my neighborhood.

-What kind of foundation can I use to support a timber frame and an 18" straw bale? What if they want a full basement? Alaskan slabs? And keeping the base of the wall dry? And they can't afford a stone stem wall...

-What is the real performance of the insulation? The ICF industry somehow gets to claim R48 on their 3" of foam and 10" of concrete. I don't think so. The thermal mass argument needs to be taken with a big grain of salt in New England. If it's 25 degrees outside on the north side of your house for 3 months, and 65 inside, what's that thermal mass doing for you?
I very much like the straw/woodchip clay walls, but I don't think their R-value will ever approach cellulose or foam. I've seen the numbers somewhere, and they are pretty good, but I'm not sure if they'd meet code where I live. As much as codes are a downer, the insulation standards may actually be worthwhile. Maybe. Depends on how uncomfortable you're willing to be.

-How do you insulate the roof? You need LOTS of insulation in Mass. Are you going to put 3' of loose fill straw/clay up there, and how do you frame around that?

These questions go on and on. In summary I guess I'm saying any of these materials can work great, but there are some issues with any of them. I don't think the TF industry standard (SIPS) deserves all of the props they get in the marketing literature, but I also don't think they're evil. I also don't think you'll be karmically reincarnated as a newt if you build your walls with straw/clay and put rigid foam on the roof. It's a spectrum, and there's lots of variable involved--climate, cost, what materials are available, interior and exterior finishes, comfort of the owners, and on and on. And just like every other design problem, you've got to come up with a solution.

Brad

and note I never said anything about batt insulation. I would argue that that stuff should never be used, at least where I live.

timberwrestler wrote,

"When I was raising my first timber frame (my house), my friend said wait, you're going to build a whole separate wall outside of the frame? The only way it can make sense is to justify it in terms of the whole open building concept, that the structure is distinct from the enclosure."

What do you mean, the only way it can make sense? Why is the 'open building concept' the only answer 'making sense'? Apply the same logic to single vs double pane windows and see how far it gets you. Obviously having a full timber frame and then a full stick frame exterior to it is using far too much material for the loads to be borne, however, that's where a reassessment of design comes in handy - refer again to your final comment in your piece.

"I've come up with all sorts of design questions in trying to insulate spaces including (but not at all limited to):

-what is really local? Are the SIPS made 100 miles away local?"

I'll go with that. I suspect defining 'local' is a bit difficult, but it surely is within a day's drive. Some would argue walking distance, others would suggest horse and cart distance. I think when we get into sea freight, air lift, and trucking from the other side of the continent, we are beyond 'local', no?

Perhaps 'local' could refer to a general climatic and ecological zone??

"The cellulose from local newspapers with studs from Siberia?"

Hah - where'd the pulp for that newspaper come from? And definitely 'no', the studs from Siberia aren't 'local' in New England.

"How about studs sawn from the site?"

Can't get much more local than that.

"What if you then sheath it with plywood?"

Depends upon the source, both of the material and the plywood mill.

"Clay from the site?"

What's more local than that?


"They don't grow much straw in my neighborhood."

Well they are starting to - a CSA for grain just started in Amherst, MA, and there are grain producers up in Quebec, which is within a day's drive. Further, straw can be replaced very well with wood chips, which are abundant where you live, and are superior in some respects, especially in wetter areas.

I think an over-emphasis on the transportation equation is a little misleading. Most products I have looked at, if you look at the overall environmental impact, the transportation component, even if the stuff comes from overseas, is not a large percentage of the footprint -well under 10% for a lot of products from what I understand. I would say that embedded energy in manufacture is at least as big a component. That factor, for me, rules out SIPS, even if they are made next door. I don't want the factory to take over my trade, so I can't support that industry. I can't find a way to accept the landfill problem at the end of their usable lifespan either. SIPS suck.

"What kind of foundation can I use to support a timber frame and an 18" straw bale?'

Easily solved problem.

What if they want a full basement?

then they can have one too.

Alaskan slabs? And keeping the base of the wall dry? And they can't afford a stone stem wall...'

There's concrete and vapor break between wood and concrete.

"What is the real performance of the insulation? The ICF industry somehow gets to claim R48 on their 3" of foam and 10" of concrete. I don't think so."

Neither do I. Who needs R48 foundation anyhow?

"The thermal mass argument needs to be taken with a big grain of salt in New England. If it's 25 degrees outside on the north side of your house for 3 months, and 65 inside, what's that thermal mass doing for you?

I guess that if one lived in a house with only one wall, this might be a concern.

"I very much like the straw/woodchip clay walls, but I don't think their R-value will ever approach cellulose or foam."

Inch for inch, no, however the clay woodchip wall can be made thicker to suit - at 12", apparently R24 - isn't that adequate? Besides, the benefits of having clay in the wall run to more than simple R-value, and you know that I'm sure.


"I've seen the numbers somewhere, and they are pretty good, but I'm not sure if they'd meet code where I live. As much as codes are a downer, the insulation standards may actually be worthwhile. Maybe. Depends on how uncomfortable you're willing to be.

If one is masochistic, that is one thing, but there's no reason one can't be quite comfortable in a house with light clay/woodchip walls, or straw bale walls. And code, well, that serves industry and the insurance companies more than anything else. There is possibility of amendments and special green building codes if consumers demand it and builders promote it - it's happening in some places.

"How do you insulate the roof? You need LOTS of insulation in Mass. Are you going to put 3' of loose fill straw/clay up there, and how do you frame around that?"

That is a good question, and one of the design challenges to using alternative insulative materials. I can think of any number of solutions, but perhaps some use of conventional insulation products in the ceiling and roof space might well be justified for a lot of folks, especially if they are greatly reducing the use of those materials in the rest of their structure. I don't know about 3' of insulative material being necessary, though I can certainly think of ways to frame that in if that was the objective, and I'm sure you could too timberwrestler.

"I don't think the TF industry standard (SIPS) deserves all of the props they get in the marketing literature, but I also don't think they're evil."

I guess you hadn't heard, that at Lord Vader's command, the entire Death Star was built from SIPS? Saved a lot of labor time - they put the Death Star up in little over a week and are getting R100 from the custom 60 sq. km size panels....

"I also don't think you'll be karmically reincarnated as a newt if you build your walls with straw/clay and put rigid foam on the roof."

What would be wrong with a newt? Certainly smarter than some folks I heard on talk radio lately. Kidding aside, you are right that it isn't always practical to be totally purist, and having walls that are light clay and foam in the roof is going to be an acceptable compromise to most folks, I would think

"And just like every other design problem, you've got to come up with a solution."

Exactly.

Derek, be careful of what you wish for, the Mayan calendar ends in a few years. We are entering a new galactic age.

I have been through all the issues brought up and seem to have reasonably addressed them to my satisfaction.

I have access to every item I would need with out going to the building supply store, with the exception of cellulose and screws. I would not insulate the roof. It will be strapped across the rafters and wooden shingles applied. I have even looked into granite, as a previous thread will attest too. Use the hot attic for drying herbs or something.

I grew up in a house built in the 1970, it used 2x4 studs with 3-1/2" of fiber glass, R-13. It is still lived in, this winter it burned 2 cords of wood. I will be happy with 12" of clay and chips. If the house is heated with oil I can see super insulating it. I do not plan of using a fossil fuel to heat my home, the wood will be salvaged or cut on my own land my me and my family.

Some great comments and thoughts.

Tim

Uh, are you calling me 'Derek' now? I must have missed the memo. I've been called 'Paul' a few times, but 'Derek' is a new one.

Oh, by the way, I hear that Death Star Industries® looks to be achieving Leeds Platinum certification for their new line of Death Stars...

And just remember who was in power before the 'empire' took over. A pseudo religious cult and you had to have certain 'genetics' to be accepted into the ruling and warrior class. Then the empire comes along, turns it all on its head in the name of order... and the previous ruling party goes into hiding, gets all disruptive, etc.

And what of the Death Star? How many thousands of innocents must have died when our fearless 'rebellion' blew it to bits. I mean - certainly - there must have been thousands of moms and pops and 'normal' folks on there just trying to make a living, doing the best with the hand they were dealt - you know, punching the clock as a stormtrooper, or TIE fighter mechanic, or robot repairwoman.

Black and White is so last century.

-Mike

Naw, I think I'm starting to like the term 'Derek' a lot better, given its meaning in old German of "ruler of the people" - sure beats my name, "bearing the body of Christ" all the time.

I understand that Death Star Industries® is planning a whole line of Death Stars©, from the basic Icosohedral 'Mini Death©' to the flamboyant 65537-gon model, Death Max©, which incorporates the latest in panel connection technology - all that's needed is a socket wrench, and a few thousand laborers.

The key to these exciting new developments was the 'negotiation' with the Ewoks, where it was found they could be most advantageously coerced - I mean 'induced' - to work for pennies a day doing utterly mundane unskilled labor. Why, you'd be amazed what those little gippers will do for a buck! also, they are remarkably tolerant of workplace toxins, and when one keels over, there seems to be a line up of other Ewoks just waiting to take their place.

And when the lifespan of a SIP-paneled Death Star© comes to an end, why we just shuffle them off into the nearest sun, where they are conveniently burned up, 'No fuss, no muss', that's the motto of Death Star Industries....

nah, the ewoks eventually sold out to 'harvest' their forests so that jedi masters could build really exotic furniture and timber frames with the old growth materials.

i think you are mistaking them for the sand people, or maybe the humans. oh wait, we're already there - its just that its not death star industries that necessarily creates all this trouble, but perhaps the folks who keep them in business... you know, those people all around us, those people just like us.

I'm not keeping Death Star Industries in business, though I hear they have an opening in the marketing department, and it probably pays better than my current line of work, so maybe I should think about 'moving up'.

There's talk of a new line of branded merchandise at Death Star, starting with Animosité Pour Homme ('Animosity for Men' when sold in the French market), a new fragrance for the man of today, and soon there will be a clothing line I'm sure...

So, who in this thread has worked with the 'dreaded' SIP? Installed it, engineered it, made it, cut it, etc. etc.? Just a curiosity poll... wondering who has hands on experience...

Chris, this is the Derek I was speaking to, with his underwater city and mammoth tusk's. The rest of my comments weren't directed toward any particular individual.

I am now watching a DVD titled, The Great Year. It deals with the precession of the equinox, the age of civilization, the question of the earths wobble, and more.

Tim