Petrol-free home: Petrol-free housewrap
So I’ve got a plan that promotes petrol-free materials throughout the lion’s share of the rehab of my shed, which is a lead-in project to the rehab of my house. It involves now a metal roof; Pavatex as a insulation above the roof rafters and Roxul between the rafters; Airkrete in the wall cavity; and Foamglas beneath the Rosendale Cement-based concrete slab.
Main remaining urgent challenge to get the plans to the buildings department ASAP as far as I can tell: “house wrap” “vapor barrier” situation.
I keep coming up short here, and it’s maddening. The best option I’m coming up with at the moment is pine tar paper. Unfortunately, it’s seemingly impossible to source on the marketplace anymore. I may end up soaking cotton rags or kraft paper with pine tar and applying them to the exterior wall sheathing. I may need to mix the pine tar with something to optimize effectiveness, though I reckon pine tar itself is up to the task.
Another option is to apply the pine tar directly to the old wood sheathing. I wonder about permeability issues here, which is why the pine-tar-infused kraft paper (on the interior or exterior layer of the sheathing?) seems optimal.
As for the vapor barrier between the Pavatex and the rafters/Roxul combo… well, thoughts are appreciated on both fronts if it pleases you. Thanks for your consideration.
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Replies
Greg,
What about using a sheathing that doesn't need a WRB? Something like Zip, or other wax impregnated sheathing or board insulation?
I can't comment intelligently on your plan from a practical point of view, but from a code persecutive you might encounter a few difficulties. WRBs generally have to meet prescribed standards usually set out in building code appendices. I don't know how you would get your solution approved.
Good point, Malcolm. It's an olde 1860s shed with old pine walls that's set to stick around as part of the rehab on a functional level. The plan is to keep the old pine wall as part of the overall plan. Wax impregnating versus pine-tar coating? I'd considered adding another sheathing layer, indeed. Seems a bit overwrought even for me; however, may be it's a wise way forward. The plan may still involve a rain screen - but even still, that WRB may be necessary for code.
First, what makes you think a vapor barrier is even called for?
Using Gutex Multitherm (similar to Pavatex) as the sheathing would be both weather resistant (the primary function of housewrap), but also vapor permeable, allowing the assembly to dry readily toward the exterior:
http://gutex.de/en/product-range/products/product/gutex-multitherm/
There are other brands weather resistant fiberboard products available in Europe, but apparently Pavatex doesn't make a weather resistant version, according to the verbiage on the Pavatex Combi wall sheathing product web page:
http://www.pavatex.com/en/products/wall/pavatherm-combi/
In Canada SONOclimat ECO4 sheathing could work, if you can find a local distributor (availability is primarily in Quebec):
http://www.mslfibre.com/Produits/Fiche/13/SONOclimatECO4
Greg,
Where are you finding FoamGlas?
I keep reading that a vapor barrier is needed, Dana? As a newbie in this area (and being a first-time houseowner), I still take direction from "experts" at points. I'm attaching the current plans, which are set to be tweaked one final time - but are almost there. I was told by the buildings dept rep that vapor barrier isn't needed if foam is used? Airkrete seems to meet that standard. The architect slotted in there the vapor barrier on the wall anyway.
The roof... well, at this stage I have access to Pavatex via a Canadian distributor while the Gutex is another level of activation and sourcing challenge as I reckon you're aware. I could probably score it in time for the house project, which will follow the shed rehab. The shed is becoming habitable in this process - accessory apt, Airbnb, guests, or the like for what it's worth.
Thank you for both of the product leads!! I cherish this sort of information, as I seem to do so much of the digging for it on my own. I'd just drive to Quebec and score the stuff if it makes sense to slot in a project at this point.
As for FoamGlas, Steve... mmm. At this point, I'm just assuming it's sourceable. May be that's a dangerous assumption. It's made by Corning out of Pittsburgh, so again at this stage I haven't done the homework yet to ensure effective sourcing. I reckon I'll get on it!
Actually, I just found this outfit in Brooklyn that carries Gutex! https://foursevenfive.com/product-category/thermal-insulation/ Sweet... I've been in touch with the Pavatex rep for months now, so I'll probably stick with it for the small project; however, the house may see Gutex next spring. Options!
"I keep reading that a vapor barrier is needed, Dana?"
Where are you reading this?
Climate matters. Without knowing where this house is (your location is...???) it's not possible to advise with any precision about the relative safety of a stackup with or without vapor barriers. But with vented cladding and fiberboard sheathing only the very coldest parts of US would need a vapor retarder as tight as 1 US perm.
I'm aware that 475 Building Supply carries Gutex, which is why I mentioned that over similar products from other vendors. It's quite a bit more expensive than Sonoclimat ECO4 though. From your use of English it seemed possible you could be in UK or Canada, or even the US. Pavatex not being readily available in the US made me think you might be in Europe, (didn't know there was a Canadian distributor), but since Gutex is available in the US as well as Europe it seemed like the right vendor to call out. In the US-American vernacular it's usually called "oil" or "petrochemical", and never "petrol", though the latter is fairly well understood.
[edited to add]
From the elevation document we find an address in Beacon, New York 12508, which is in US climate zone 5A. In that climate you don't need a vapor barrier or Class-II vapor retarder with wood or fiberboard sheathing and a vented siding (such as any rainscreen assembly) . See the exceptions listed for zone 5 inTable R702.7.1 in the IRC 2015:
https://codes.iccsafe.org/public/document/code/553/9837123
Gregg,
There are many questions here. Some may be irrelevant -- but still, many of us are thinking the same thing: Why are you pursuing the goal of a petroleum-free building, especially when the route you have chosen is so much more expensive and complicated than using commonly available materials?
From a global environmental perspective -- or even a social justice perspective -- spending thousands of extra dollars to achieve your goal probably does more harm than good. It's a hobby, and an expensive one, but not an example of green stewardship.
Personally, I think that using petroleum to make asphalt felt is an excellent use of petroleum -- a much better use than burning the petroleum in cars (or in delivery trucks or expeditions to Quebec and New York to pick up exotic materials). But perhaps I am being unjust. Perhaps you are enlisting the help of an Amish neighbor to use a horse-drawn buggy for your drive to Quebec.
I think you might want to read this article: Do I Need a Vapor Retarder?
Martin, hi. Thanks for the link and the comment. Since you asked the question about "why" I'm pursuing the goal of a petrol-free building (and ultimately a petrol-free or very close to it property), I'll share a few thoughts.
Petroleum is a hydrocarbon and effectively a poison. The capture or use of petroleum is detrimental to the health and well being of land, the poisoning of which is unacceptable behavior IMHO. The low US dollar cost of petroleum to end users is possible only through massive market distortions maintained by large financial institutions that control the Federal Reserve as well as the US monetary system as we know it today. The Great War between nations ended in 1918; however, the war machine (including in the states the Federal Reserve and the federal income tax) created to prosecute the war was never dismantled. The war machine and those who financially profit from it shifted their focus to a war on everything. This war has been prosecuted via the creation of a worldwide marketplace for war products infused on every level with petroleum products produced via fractional distillation, which is a very resource-heavy process to maintain. The fiat debt-based US dollar is backed by petroleum alone today, and this transition from gold to petrol backed currency has been ongoing since the onset of the Great War. During this transition process, as many naturally produced competitive products as possible were banned, effectively banned, or demonized to clear the way for forced adoption of petroleum-based products and processes; to wit, alcohol, hemp, cocaine, dairy ("raw"), waterways (Jones Act), et cetera.
If petroleum isn't "consumed" in massive quantities daily in one way or the other, the banking system built on it will be forced to scale back. Bankers don't really want that scaling back to happen. Of course, they've managed to create a marketplace that constantly works to push petrol products and processes at the expense of anything else. For people who see structural issues with this marketplace, see it as problematic, and have any ability whatsoever on a financial level to make investments in products and processes that promote salubriousness, the choice to invest in such products and processes is one that is available despite best efforts of banks and, dare I write, sensible on its own merits.
Gregg,
However laudable your aim, you are still missing Martin's point: Unless you are sourcing your materials locally, and the materials do not need petroleum to be manufactured, you may be defeating your aim by using more petroleum not less.
I would add that the issues you appear concerned about are not solved in any effective way by your decision. How individual homeowners choose build custom single-family houses simply does not make anything more than a gestural difference.
I'm all about "gestural differences" as you put it, Malcolm. 100%. Rebuilding and maintaining an 1860s homestead in the middle of a small rail-enabled (so a petrol-powered vehicle is unnecessary) city in the northern reaches of the NYC metro area on a quarter acre and practicing methods that enable agrarian living to the best of the abilities of my family feels right to me. I don't plan on changing the world, and I wish you the best if that's your intention. Just living and embodying agrarian values as I'm able. If y'all want to argue that jamming petrol products inside, outside, or on top of houses is green, well I'm not going to argue with you. If you want to write that investing cash in companies outside my vicinity that are producing products that strike me as responsible is a poor use of my limited resources vis-a-vis my professed values, then by all means go right ahead. I'll read the critiques. I'll even field the sarcasm from Martin and others if it pleases them. I appreciate all the feedback. Thanks.
Gregg,
Your original question concerned housewrap. If your shed has walls measuring 600 square feet -- I just made that number up -- then you would need two rolls of asphalt felt weighing a total of 72 pounds. If the roofing felt is 50% paper by weight, and 50% asphalt by weight -- I just made those percentages up -- then the two rolls of asphalt felt include 36 pounds of asphalt.
A gallon of liquid gasoline weighs about 8 pounds, so if you burn up 5 gallons of gasoline driving around the country looking for asphalt-free housewrap, you've burned up more fossil fuel than is contained (probably) in two rolls of asphalt felt.
Greg,
Sometimes my comments try and address issues that a question raises, rather than the question itself.
That's a poor excuse for my reply. If you want to pursue building in a certain way, that's your business, not mine. Like you I don't think my actions are saving the world in any meaningful way. If you find comfort in your lifestyle, more power to you.
@Dana, thank you for your input. It's invaluable. Regarding my pedantry, it's among my many irritating qualities. ;-)
@Marti RE "From a global environmental perspective -- or even a social justice perspective -- spending thousands of extra dollars to achieve your goal probably does more harm than good. It's a hobby, and an expensive one, but not an example of green stewardship" and your wonderful felt example: You seem to have this "global environmental perspective" nailed; to wit, from this perspective it's apparently obvious that failing to use petrol products in, on, or above one's house is harmful to the globe. I can only imagine how concerned you'd become if everyone started to fail to use petrol products in, on, or above their houses. Heck - what if everyone started to fail to use petrol in logistics? I suppose from a "global environmental perspective" we'd be looking at a worst case scenario for Mother Earth. And the precious US dollars wasted? Yowsers.
@Malcol, the purpose is to eliminate petrol in, on, or on top of the structure. I'm not trying to save the world; in fact, pace Marti I'm aiming to make the world a worse place by selfishly creating a non-toxic environment for myself and my family. (Again, imagine if others indulged in such folly.) Feel free to condemn me for these acts - I know not what I do. Pace Marti, I'll next be driving a motor vehicle willy nilly "around the country looking for asphalt-free housewrap" making the globe that much worse for the wear.
Gregg,
Believe it or not, my comments were not intended to be sarcastic or dismissive of your lifestyle. My comments were made in the spirit of this Q&A forum -- intended to provide a solution to your dilemma that meets your needs. You want to reduce the use of petroleum; so do I. Unless you travel by foot, bicycle, horse, or an electric car charged by a PV array, you therefore want to reduce the amount of driving. You also want to reduce the amount of gasoline and diesel fuel used to deliver building materials over relatively long distances.
I was responding to your Comment #5, in which you wrote, "I'd just drive to Quebec and score the stuff."
In 1974, I built a house in the woods in Vermont. I've lived on the same piece of land ever since. In my early years, I aimed for self-sufficiency, trying to grow my own food and to gather my own building materials from the woods. Eventually, I realized that achieving my goal of self-sufficiency was complicated. It was a goal that didn't have any inherent merit. What I really aimed for was a lifestyle that was environmentally appropriate and respectful of the planet.
Your goal of a petroleum-free lifestyle is different from my former goal of self-sufficiency, but I recognize in you a kindred spirit. Good luck with your experiment.
Gregg,
You still didn't answer Martin's question. You're going to burn more oil as you acquire your "oil free" products vs the amount of oil contained in readily available building products such as polyolefin fabric known as house wrap. Which is itself about as inert as can be.
Oh and an FYI...Saudi Arabia agreed to accept US Dollars in lieu of gold when, in the early 1970's, the US was unable to adhere to the quasi-gold standard ($35/oz) agreed to in the Bretton Woods agreement.
It's a red herring question IMHO, John. The system is flooded with petrol, so unless you live in the sticks and have access to a woodlot, a mill, a major applicable skill set, some financial resources, the time to apply to the project, a good team, and so forth, one is left to work more or less within the massively distorted trade system in place today. In my view, logistics is the most petrol-soaked industry out there this side of finance - so I'm not going to go out of my way to trot out a horse and carriage and expect optimal material producers to do the same. I do, however, see investing in producers of petrol-free materials as worthy, with local producers always getting the nod first and far off producers getting the nod second.
I love that you guys have viewpoints and frameworks that work well for you. I'm certain you've got amazing documentation that invalidate my approach within your framework - I've seen it crop up multiple times already on this platform! That we can all co-exist is what's most important to me. Cheers.
P.S. The U.S. was "unable to adhere to the quasi-gold standard ($35/oz) agreed to in the Bretton Woods agreement." What exactly limited the ability of the feds to adhere to our commitment, I wonder; to wit: we've got a lot of skilled professionals stationed across this land last I checked.
@Steve I found this article on Foamglas vis-รข-vis the U.S. residential market. It's got a link at the bottom of it as a lead to sourcing: http://www.finehomebuilding.com/2016/04/26/foamglas-insulation-exits-u-s-residential-market
Gregg,
You have provided a link to an article written by Scott Gibson. Scott's news article was originally written for GBA, and later reprinted by Fine Homebuilding.
Here is the link to the original article on GBA: Foamglas Exits U.S. Residential Market.