For Vinay: -- Questions about foam-board choices between XPS and EPS

[ken winston caine]

Couple questions:

1. Please remind me of why (other than environmental toxicity and
flammability) early on you rejected using the 2" thick white (EPS)
polystyrene foam boards in favor of the polyiso foamboards?

2. If your only choices -- as are mine locally -- are between EPS and XPS,
which would you choose and why? (As in
http://www.homedepot.com/h_d1/N-5yc1v/R-202090328/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053
vs.
http://www.homedepot.com/h_d1/N-5yc1v/R-100320352/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053,
for instance.

3. Was an argument against EPS its lack of rigidity?

3. Was it water permeability? I understand that the EPS styro sops it up
(and loses insulating ability in the process) and that XPS doesn't.

4. If you were going to throw up a quickie small building and would be
encasing the foam boards in fidobe papercrete and a fibrous-cement-like
shell in and out, would you still rule out the less expensive white styro
boards for the initial building? Or would you forgo foam altogether?

Thanks,
ken winston caine

[Vinay Gupta (Hexayurt Shelter Project)]

Hey,

so, for Playa use, the blue board / pink board has a bunch of issues - outgassing, flammability, and the boards typically ship with a lot of curve on them which makes them a nightmare to make hexayurts out of. And tape doesn't stick to them.

Under concrete, though, I think they'd be just fine. You could go with either one, probably, but it would be well worth asking the Ferrocement gurus what they do about foam, because they do use it as a framework sometimes, and they know that process inside and out.

Good luck!

Vinay

PS: thanks for asking on the list so it goes in the archives. That's a damn useful habit. Sorry for the brief reply, V>

--
You received this message because you are subscribed to the Google Groups "hexayurt" group.
To post to this group, send email to hexa...@googlegroups.com.
To unsubscribe from this group, send email to hexayurt+u...@googlegroups.com.
For more options, visit this group at http://groups.google.com/group/hexayurt?hl=en.

--
Vinay Gupta
Free Science and Engineering in the Global Public Interest

http://hexayurt.com - free/open next generation human sheltering
http://hexayurt.com/plan - the whole systems, big picture vision

"In the midst of winter, I finally learned that there was in me an invincible summer" - Albert Camus

Twitter/Skype/Gizmo/Gtalk/AIM: hexayurt
UK Cell : +44 (0) 7500 895568 / USA VOIP (+1) 775-743-1851

[Steve Upstill]

I helped a friend build a yurt out of 2" styro boards. The structure was fine, but we found them almost impossible to tape. Nothing we tried would stick. This was in New Zealand; there may be better exotics around here, and I have had a suggestion from a scenic artist for a coating that might do the trick. But understand that it's a problem that needs to be solved.

Spray-coating them sounds like a fine application if you can get them to hold together long enough.

Cheers,
Steve
--
First Law of Corporate Machination:
You can achieve anything if you don't care who gets the credit.

[KK]

The white board is crumbly, especially the cheap foil coated stuff
that HD sells right now.
It's hateful to work with.

Blue and pink boards do have some of the disadvantages Vinay
mentioned.
But, they are far superior at rejecting moisture. Dow themselves has a
paper on it.
I need to find it again.

Now, there is a 2" thick pink board I saw locally at Albuquerque HD
locations. It was the only one available.
I believe it was Owens Corning Foamular 150. Comes in many different
densities.

But, inside ferrocement? Doug Lacy uses plain blue board. See his
pics.
I believe every other concrete application would use them too.
Superior waterproof performance (no reduction in R value over the long
term).

Outgassing? I dunno.

Read this page that lists all types:
http://bit.ly/rmNjxN

"Polyurethane and polyisocyanurate are both closed-cell foams. They
contain low-conductivity gases in the cells (usually one of the HCFC
or CFC gases.) The higher R-Values (R 7.0 to 8.0) are the result of
thermal resistance of the gases in the cells. This can lead to a
couple of disadvantages including: off gassing of HCFC or CFC gases,
and reduced R Value over time as the gas escapes."

They say foil foam board (Thermax etc) are the ones that outgas. And
the gas escapes, leading to the R Value loss.


Here is the MSDS for *all* pink boards from OwensCorning:
http://bit.ly/qg1qDl

MSDS for Super Tuff-R:
http://bit.ly/ny2oHQ

The hydrocarbon blowing agent for Dow Super Tuff-R is a "trade
secret" (read MSDS).
So we don't know *what* it is or *what* is in it at all.

I'd like to see actual outgas hard data for the pink and blue boards.
As in, a document on it.



On Aug 2, 7:07 pm, "ken winston caine"

<k...@mindbodyspiritjournal.com> wrote:
> Couple questions:
>
> 1. Please remind me of why (other than environmental toxicity and
> flammability) early on you rejected using the 2" thick white (EPS)
> polystyrene foam boards in favor of the polyiso foamboards?
>
> 2. If your only choices -- as are mine locally -- are between EPS and XPS,

> which would you choose and why? (As inhttp://www.homedepot.com/h_d1/N-5yc1v/R-202090328/h_d2/ProductDisplay...
> vs.http://www.homedepot.com/h_d1/N-5yc1v/R-100320352/h_d2/ProductDisplay...,

[KK]

I know this is rehashing things...

Dow claims:
http://bit.ly/oQ1bNi

"Do THERMAX™ Polyisocyanurate Insulation or TUFF-R™ Polyisocyanurate
Insulation outgas any toxic materials/gases?

THERMAX™ Polyisocyanurate Insulation and TUFF-R™ Polyisocyanurate
Insulation do not outgas any toxic material over their lifetimes. Foam
insulation, like wood and other organic materials, can release toxic
smoke if ignited."


Ok.

Still looking for info on the Owens Corning pink.


But I did find this unrelated bit from aircraft builders:

"On pink vs blue, blue floam from Dow was known (a long time ago) to
not use any silicone in process. Silicone can seriously mess with the
bond strength of epoxy, and so (a long time ago) the Rutan Aircraft
Factory told us to only buy blue.
Pink foam is Owens-Corning. It and others have an unknown silicone
status. But then, the same thing may be said of Dow at this date...."

They use silicone in the production process somewhere. This means
there might be silicone residue on the outside of the panels. This is
why tape won't stick to blue and pink boards.

[KK]

Outgassing info on pink/blue foam boards:

http://www.sumidacrossing.org/SumidaCrossing/MaterialSafety.html

"The typical “insulation” foam panels, including Owens-Corning’s pink
Foamular brand, are Extruded Polystyrene (XPS), which is basically gas
bubbles trapped in foamed plastic which has been extruded, so the foam
is easier to cut along its length. At present, the gas used is
typically a hydrochlorofluorocarbon (HCFC), which is “relatively non-
toxic” and harmless to humans in the small quantities released by
cutting foam (it is bad for the ozone layer, however)"

"I have seen some online comments about outgassing, but aside from
burning it, there’s nothing in the MSDS about airborne hazards other
than dust from polystyrene foam. Polystyrene is a stable material,
which does not decompose over time (unless exposed to ultraviolet
light, e.g., sunlight). Urethane-based foams are a different matter,
and this may be the root of some of the confusion in online posts
about foam materials."

--------------------------
So, Polyurethane foams do outgas something nasty and decompose , but
none of us use even buy or use them.

Dow claims Polyiso (Thermax and Super Tuff-R) does not outgas
anything harmful.
But the "hydrocarbon" blowing agent is a secret.

Jury is still out on pink/blue polystyrene. Unless somebody has a
document.

[KK]

Ok, in looking at the outgassing of polystyrene (pink/blue board), I
came across this stuff.

The "outgassing" hazard might not actually exist in the way commonly
stated.

Surfboard makers, signmakers, and aircraft builders have spread a
"myth" of outgassing.
It's actually delamination of their applied coverings from silicone
used on the *outside* of the pink/blue board.
Epoxy, tape, and fiberglass mixed with adhesives of many types do not
stick to silicone.

Now, the environmentalists complain about raw Styrene exposure of the
*factory* workers.
And the exposure of nearby populations to the "offgassing" from the
plants *making* the polystyrene.
The "offgassing" from these plants/factories also mess with the ozone
layer.
This is the true "offgassing".

Also, if you cut pink/blue polystyrene with a hot knife, you are
remelting the plastic.
Thereby releasing styrene "gases" locally in your face.

By itself, pink/blue board should not emit anything just sitting
there.

I would still like to see an exact study document that proves
"spontaneous outgassing" from pink/blue polystyrene.
That may not be forthcoming, for the reasons stated above.

[kenwinston caine]

Am probably going to forgo the foam altogether and just build a
conduit hexayurt frame (modified and larger than what we're currently
doing and with a higher pitched roof. Am leaning toward a 24'
diameter, two story or 1-1/2 story high hex shape. 1-1/2 is probably
tall enough to have a decent-sized, comfortably usable loft.).

Once the conduit frame is up, then I'll cover its interior in scrap
fabric and scrap cardboard and heavy paper, etc., and (in stages)
spray a hard structural shell coat, locking into the conduit frame.
Then build up with natural insulations (fidobe claypapercrete type
materials that I can pump and pour into upright, in-place forms on the
walls, and that I can pump/pour into roof forms laid flat on the
ground). And once I have the desired thickness of about a foot --
which should give me somewhere between 36R and 50R for walls and
ceiling -- spray an exterior hard-shell over it all.

Am also designing conduit, bolt on eaves/supports and will be
integrating those so I can have good guttering for water catchment.
Those will bolt directly onto the conduit wall frames and will be
built up and sprayed as a roof extension and as part of the whole
structure.

Going to try to learn one of these free online CAD drawing programs so
I can get away from my hand-drawn sketches and be able to easily share
ideas and get input on their feasibility and structural integrity.
Anyone have suggestions for the one with least learning curve and
greatest ease of use?

Originally was thinking of using foamboard just so I would have a
structure up in a day or so. And was going to use that as the
underlayment and structure -- instead of using welded conduit to
define the shape and serve as initial structure.

Aside on welding conduit:

(Welding conduit is nasty and life-threatening. You have to strip the
zinc galvanizing material off first for at least 6" around every weld.
And that requires hydrochloric acid. You have to wear a respirator
during the whole process to avoid the lethal fumes produced -- both
from skinning the galvanizing materials and from welding and still
potentially heating some galvanizing materials. Just a warning to
anyone thinking of trying this at home. You can do it. But take all
the precautions. And study up on it first.)

Welded connections are much stronger and lasting than bolted ones. The
connections are the weak point in just about ANY structure.

Now we return you to our regular programming:

Sizing, cutting, welding conduit will take mucho mucho longer than hot-
knife cutting foamboard sheets to appropriate sizes and angles.

If using foamboard, Steve, was planning to attach pieces using Liquid
Nails Heavy Duty Construction Adhesive. The "Heavy Duty" version of
Liquid Nails is said to bond permanently with foam and supposedly is
tacky adhesive in 5 minutes and well set up in 30. That doesn't give a
tension ring, but the bond might be so integral that a tension ring is
unnecessary. Not sure. That's speculation. Tension ring can still be
added.

Haven't checked the Albuquerque stores, KK, but the only two kinds of
foamboard available at Home Depot in Santa Fe currently are the
Foamular -- at $26 per 2" thick sheet -- and the non-foil-coated EPS
whiteboard at $16 per 2-inch sheet.

So I was wondering, why not use the cheaper stuff since I'm only using
it to hold the shape of the building while I hard-shell spray it with
a mortar sprayer. (www.mortarsprayer.com)

There is a huge issue with getting any kind of mud to stick to various
forms of poly. (Hadn't considered that the same issue would apply to
tape, Steve; that's interesting. How did you solve that eventually, or
did you guys give up?)

My understanding -- based on advice from Nolan Scheid at www.mortarsprayer.com
-- is that adding acrylic to the mix makes it much more likely that
the foam will not only like it a lot, but become attached to it. So
was figuring I would be experimenting with various mixes of cheap,
powdered acrylic paints. (Which also might add interesting color
tinting of my choosing to the mud mix -- although this would be the
first, thin coat -- an adhesion coat -- which would be covered over by
later, thicker coats. So I'd only enjoy the color for a few moments or
day or two at most.) (Nolan uses flooring acrylic.) And Nolan
suggested sprinkling or otherwise laying on fibers of various sorts
including straw and strips of cloth onto the first wet, sticky coats.
Hopefully that helps someone else. He also uses a texture sprayer for
the first thin adhesive coats. (We were specifically discussing
getting sprayed fidobe or cement to adhere to inflated poly sheeting
in arch-shaped forms. But the same advice can be extended to any
adhesion resistant poly surface. Once that initial thin sticky coat is
firmly attached to the poly, then you can begin building up thicker,
heavier coats.

If using portland cement mixes in your mud, it becomes a structural
shell, when hardened, at a relatively thin thickness when creating
arches. For instance, Nolan said, "When using this approach with
cement, fiber acrylic and vermiculite, once it about 3/8” thick the
shell is strong. Once the shell is strong, you can switch from a
texture sprayer to a stucco sprayer and start building the structure
thickness much faster."

I'll be experimenting with this process with the hexayurt shape on one
building going up over the next two months. And the larger building --
which may not get underway until late Spring 2012 -- will probably use
the inflated arches design that Sri Ananda Sarvasri uses. (http://
planetaryrenewal.org/ipr/ultralc.html)

May still use some foam board to form a super small structure -- such
as a 4'x4'x8' tall battery room for my solar power system. And / or a
small shed building for storing tools and my generator. And will
experiment then with spraying foamboard and seeing how well I can get
a structural shell mix of mud to stick and firm up. Seems like a
really quick, simple way to build a small shed, doesn't it?

Another adhesion and strengthening trick I read recently was to wrap
each piece of shaped foam in wire or nylon window-screen netting. This
is used in the construction fascia pieces. Is said to strengthen the
finished product and make them impervious to beak pecks from birds, as
well as increasing the ability to get cement stuccos to easily adhere
to the foam.

So, for the most part, in my current project, I guess I'm forgoing
foam altogether for the main buildings.

One of the other reasons I was considering using foam board was
related to the speed of construction with it. I was just imagining how
satisfying and motivating it would be to see a whole building shell
take form on my land in a day or two. (Just the tied-down, glued
together foamboards, with windows and door openings cut out. From
leveled site to building in *poof* a day. Guess I'll miss that
thrill.) Since I'm doing a permanent building, I don't need to make it
go up in minutes or use potentially toxic materials or spend the more
than $1,000 it was going to cost if I made the initial structure of
Foamular.

Hope at least some of this is useful.

Best,
ken winston caine

On Aug 2, 11:16 pm, Steve Upstill <upst...@gmail.com> wrote:
> I helped a friend build a yurt out of 2" styro boards. The structure was fine, but we found them almost impossible to tape. Nothing we tried would stick. This was in New Zealand; there may be better exotics around here, and I have had a suggestion from a scenic artist for a coating that might do the trick. But understand that it's a problem that needs to be solved.
>
> Spray-coating them sounds like a fine application if you can get them to hold together long enough.
>
> Cheers,
> Steve
> --
> First Law of Corporate Machination:
> You can achieve anything if you don't care who gets the credit.
>
> On Aug 2, 2011, at 6:07 PM, ken winston caine wrote:
>
>
>
>
>
>
>
> > Couple questions:
>
> > 1. Please remind me of why (other than environmental toxicity and
> > flammability) early on you rejected using the 2" thick white (EPS)
> > polystyrene foam boards in favor of the polyiso foamboards?
>
> > 2. If your only choices -- as are mine locally -- are between EPS and XPS,
> > which would you choose and why? (As in

> >http://www.homedepot.com/h_d1/N-5yc1v/R-202090328/h_d2/ProductDisplay...
> > vs.
> >http://www.homedepot.com/h_d1/N-5yc1v/R-100320352/h_d2/ProductDisplay...,

[Vinay Gupta (Hexayurt Shelter Project)]

Most useful thank you!

<k...@mindbodyspiritjournal.com> wrote:
> Couple questions:
>
> 1. Please remind me of why (other th...

> which would you choose and why? (As inhttp://www.homedepot.com/h_d1/N-5yc1v/R-202090328/h_d2/ProductDisplay...
> vs.http://www.homedepot.com/h_d1/N-5yc1v/R-100320352/h_d2/ProductDisplay...,

> for instance.
>
> 3. Was an argument against EPS its lack of rigidity?
>

> 3. Was it water permeab...

[KK]

Ken, if you are going to encapsulate a building the white foam should
be just fine.
Just make sure the density is what you want.
They grade it just like pink/blue board.
It's all styrene based stuff, just different "toughness".

But HD always carries the worst and cheapest grade on the shelves.
To get high density foam boards of *any* type, you have to go to a
specialist supplier $$$



On Aug 3, 2:11 pm, "Vinay Gupta (Hexayurt Shelter Project)"
<hexay...@gmail.com> wrote:
> Most useful thank you!

No problem!
I don't believe Dow is lying about Polyiso outgassing (?)
We would have to see testing of any of these foam boards really.

I do believe pink/blue polystyrene may be safe, just not if you hot
wire cut.
I'm glad I know this now.

They did studies showing how white styrofoam cups and plates release
styrene.
I can see how this works. It's not outgassing (unless you burn them).
The mechanical action of liquids and scraping a fork along styrofoam
plates would mean you are ingesting bits of styrene.
It's nasty stuff. But fairly inert if it's just foam boards in a wall.

Though, for my middle project, I may encapsulate the pink/blue with
white elastomeric roof coating on both sides.
That might be a viable safe route to go down.

Elastomeric does not burn. And is super common at HD.
$115 per 5 gallons for Henry "Enviro White" (better longer lasting)

http://bit.ly/nsraMM

You could tape a hexayurt and coat it with this.
It would glue/seal the tape down and provide UV protection for tape.
Plus the overall waterproofing aspect.
This assumes you are going to leave the hexayurt up "forever".

My big project will be a skeleton frame OSG with blown cellulose
inside.
There will be no foam board used.

Will do that one by next March.

[ken winston caine]

5 gallons is 4.75 gallons in 2011.

I was surprised to find that out. That way with ALL the coatings, not just
the elastomeric white. (Didn't check to see what a 5 gallon paint bucket
holds these days. Need to do that next visit.)

The Henry's white elastomeric coating doesn't spread very far. I've used it
before. It's nice, but doesn't spread at all like the typical "aluminum"
roof sealing tar you brush on with a roof-coating broom. At least, didn't
for me.

Best,
ken winston caine

http://bit.ly/nsraMM

[ken winston caine]

KK, I just looked at the listing you posted for Henry's white elastomeric
coating and it does say 5 gallons in the listing.

Am certain that just last week I priced that same stuff at the Santa Fe Home
Depot and saw that it now was 4.75 gallons. BICBW.

-- ken

----- Original Message -----
From: "KK" <koffeek...@gmail.com>
To: "hexayurt" <hexa...@googlegroups.com>
Sent: Wednesday, August 03, 2011 3:22 PM
Subject: [hexayurt] Re: For Vinay: -- Questions about foam-board choices
between XPS and EPS

http://bit.ly/nsraMM

[KK]

Hmm...I'll look out here and see what they stock. They "looked" like 5
gal buckets.

I applied something like Henry's with a Graco airless sprayer (large
model from HD).
It can go on thin really easy that way. Helped out on a *big* roof job
in Ruidoso.

I want to find out what the smallest size sprayer does with Henry's.
Might be a way to shoot it with a hand held cheapie.
Or maybe even with air compressor and autobody undercoating/primer
gun.
That would be a cheap, common way to do it.
Airless is the best for this thick stuff though.

Note on the Henry's, the Enviro White is the "mid" grade. They make
more expensive stuff.
Henry's is tough with the MSDS and descriptions of their products.
Like confusing on purpose almost. Probably a marketing deal.
Anyway, the Enviro White had a longer warranty and better specs,
similar to their more $$$ products.
I think that it would be a safe bet.
The cheapest stuff had some almost deliberate marketing bullshit going
on.
I think some of it related to the "wateproofness". I'd avoid it (it's
$80/5gal?)




On Aug 3, 4:04 pm, "ken winston caine"

[KK]

On Aug 4, 2:15 pm, KK <koffeekomma...@gmail.com> wrote:
> Hmm...I'll look out here and see what they stock. They "looked" like 5
> gal buckets.

?hl=en.


Here is the deal. Just got back from HD.
They *are* 4.75 gal. on the label. Bucket looks like a standard "5
gal"


687 Enviro White is $115. 12 year warranty. Rated for ponding water.
587 "plain" (thickest) was $99. 10 year warranty. Rated for ponding
water.
287 Solarflex is $77. 7 year warranty. *NOT* rated for ponded water.

So...the middle grade is "thicker".
The cheapest stuff is *not* "waterproof".
Enviro White supposedly repels dirt better and has longest warranty
(toughest?)

I'm going to go with the Enviro White for testing.
Coyote shit filled blowing dirt is New Mexico's #1 hazard right? ;)
I should be firmly on the safe side choosing that product.

That's the report from the field.