Types of foam

[DogStar]

Good day all!

Wondering about types of foam. Pink, blue, white, foil backed... I am sure there are more.

My 1st ?: I have a bunch of 1 inch 4x8 sheets of white foam. Is this worthwhile using in order to save money that could be put to other use on my Tear? Or are other foam products far superior?

2nd?: It doesn't seem that lots of people use the foil backed foam. Is there a reason to not using it?

3rd?: Does anyone use "conventional" fiberglass batting for insulation? I sort of think not since it would add nothing structurally to the project. (Again I have some in stock.) Saving $$$ is always going to be important.

The guy always with the questions...
My notebook is getting full of notes!

Thank you,
Eric

[bobhenry]

Since you are like so many paranoid folk without a city & state on your avatar I went to your website to find out where you were.

In Conneticut huh ! If you are a cold, or even cool , weather camper spring for the foil backed polyisocianurate it is the best R value for the thickness. The white styrofoam board shrinks do not encapsulate it in a wall where there is no access. The pink and blue are good and exactly the same except for color (Dow vs Owen corning). The Dow blue is what I used but the foil face adds a full 1 point to the r value and although a bit more expensive you only buy it once so why not?

We just went thru a thread about r values . Here is a bit of info I was able to unearth......

Panel #1 is a stick built panel w/3/4" Styrofoam insulation consisting of;

2 sheets of 1/4" plywood .31 ea .62 R
32sq foot of 3/4 Styrofoam 20.4 sq ft 3.75 x .64 = 2.4
7. 8' 1X3's 11.6 sq ft .93 x .36 = .3348
so your composit 1x3 and foam wall is 2.735
Wall #1 total "r" value is 3.355
A bottle of glue n/a ?
a hand full of nails and a quart of paint (inside finish)

You can add 1.056 to this wall by substituting 3/4 foil faced polyisocyanurate ( 5.4 "R" value) in lieu of the blue (or pink) foam

Panel #2 is a solid sheet of 1/2" plywood with a foam backed rug glued to one side consisting of;

1 sheet of 1/2" plywood .63
32 sq foot of foam backed rug 1.23 (see note)
wall #2 total "r" value is 1.86
1 quart of rug glue n/a

curiously a material backed carpet is 2.08 instead of the rubber backed 1.23 ndicating the foam rubber is a better thermal conductor of heat and cold.

here is some more info.....http://www.homeconstructionimprovement.com/foam-board-insulation-values/

[GPW]

Just a guess , I think the fiberglass insulation "could" be used if it were "bagged " in plastic sheeting ... to keep the itchy's away probably a poor substitute for the foam ... and then there's the settling in walls ...

Sometimes it just comes down to ... "Use what ya' Got"

[absolutsnwbrdr]

The fiberglass batt insulation will only live up to its R-value when used in the proper wall cavity. If you were to compress it into a 3/4" space for a teardrop, the r-value would probably be negligible.

[absolutsnwbrdr]

I used some of the foil backed insulation for my removable insulation panels and it works well.



Oh, and the blue/pink foam that i used was actually green

[DogStar]

Here are some specifics I found:
FWIW,
Eric

Expanded polystyrene (EPS) (White)

Expanded polystyrene (EPS)
EPS is the insulation used most widely in insulated concrete forms and structural
insulated panels. EPS has the lowest average R-value of the three types of rigid-foam insulation, around R-4 per inch. At about 19¢ per sq. ft. for a 1-in.-thick 4x8 sheet, it also costs the least. Although EPS is acceptable for ground contact and can be treated to resist insects, it does absorb water. When applied as sheathing, EPS should be used over housewrap. Most EPS is unfaced, which means it is fragile to work with and is considered semipermeable, so it does not create a vapor barrier.

Extruded polystyrene (XPS)

Extruded polystyrene (XPS)
Easily recognized by its blue, green, or pink color, XPS falls in the middle of the three types of rigid-foam insulation in both cost and R-value. At about R-5 per inch, XPS costs around 42¢ per sq. ft. for a 1-in.-thick 4x8 panel. XPS comes unfaced or with a number of different plastic facings. Unfaced 1-in.-thick XPS has a perm rating around 1, making it semipermeable. Thicker and faced XPS is stronger and can have a lower perm rating, but either way, it is considered a vapor retarder, not a vapor barrier.

Polyisocyanurate (ISO)

Polyisocyanurate (ISO)
ISO panels are expensive, costing as much as 70¢ per sq. ft. for a 1-in.-thick panel, and they pay off with (aged) R-values as high as R-6.5 per inch. (R-values start around R-8 and degrade slightly over time.) Because ISO starts as liquid foam and has to be sprayed against a substrate to form a rigid panel, all ISO panels are faced. A few different facings used on ISO affect the performance of the panel in both durability and perm rating. Foil-faced ISO panels are considered impermeable. Because applying these products as sheathing creates an exterior vapor barrier, they never should be used with an interior vapor barrier. More permeable ISO panels are faced with fiberglass and can be used without creating a vapor barrier.

[Kursac]

LOL look at you. You went and outed him and told everyone where he lives.

I am sure he just hasn't gotten around to updating his profile LOL I sure if he was Paranoid he would not have posted his pickup on the web

[DogStar]

LOL look at you. You went and outed him and told everyone where he lives.

I am sure he just hasn't gotten around to updating his profile LOL I sure if he was Paranoid he would not have posted his pickup on the web

With my phone number on it even....

Eric

[Wimperdink]

I would use what I already have. I doubt that you'd notice the diff between the foilbacked 1" that you already have vs. anything else.

[DogStar]

I would use what I already have. I doubt that you'd notice the diff between the foilbacked 1" that you already have vs. anything else.

If not for anything else I will use it in the floor which because of the design (this being a self contained, removable capsule, so to speak) will have 2 inches "cavity". My white foam is a full 1 inch thick.

Eric

[Wimperdink]

I just rebuilt my canned ham which came with fiberglass insulation that was no more than 1/2" at full fluff. I discarded that and went with 3/4" white foamboard that was given to me. I expect to be a lil warmer this year.

My wazat was built with aluminum frame and 1/2" white foamboard in the walls, cielings, floors. There was large gaps that didn't get insulated. We slept in it down to 17*F. All it took to keep us warm at that temp was the smallest electric heater that wally world sells. My take on it is that a teardrop is too small to put a lot of thought into all the diff types of insulation... put in what you have and carry a heater and a sleeping bag. Once you open the door, all the heat is gone anyway.

[Kursac]

Well I do agree that a tear is a small space the floor and roof is where all your loss will be. But as stated in many of these insulation threads condensation is also a very important to insulate. I also agree that your white foam will be fine and more important it is all ready in the budget.

[sdakotadoug]

If your using foilbacked foam, I assume that the foil goes to the outside. Correct? or did I blunder again. Doug

[aggie79]

If your using foilbacked foam, I assume that the foil goes to the outside. Correct? or did I blunder again. Doug

Foil is a radiant barrier and has no insulation value itself. To be effective, and to add insulating value, there needs to be an air space adjacent to the foil. Since most fill the voids with insulation, the foil doesn't really add much.

The foil faced "bubble wrap" works by providing its own internal air space.

[johnb]

Yes the foil without at least 3/4 inch air gap has no insulation value.

I recently put spray foam into a house which is amazing stuff. The r-value is only good through the middle of the material - most heat is lost around the edges. If I were to do this again I'd use the blue/pink board and seal the edge with expanding window sealer foam. Due to the expansion and contraction from sun/cold you definitely want to spring the extra dollar for the flexible window/door sealant.

My mistake was to maximize the interior width and I went with sidewalls that are only 3/4 ply with aluminum exterior. Not much insulation. Also the window in the doors is single pane - big heat loss. Doesn't matter how well the roof and floor is insulated if the walls and door are freezing. Despite this we've been in below freezing temps with only minor complaints.

Good luck!
John