How much do I need to insulate?

[fornesto]

My current plans include insulating the entire ceiling (3/4" polystyrene foam) and front wall (same). I will not insulate the 1/2" walls or 1/2" floor. I will be using a real mattress which I've heard will insulate the bottom.

I really would prefer not to insulate the sidewalls due to the expense, effort and loss of interior width. I also don't want to put in a roof vent. I would like to compensate by adding a second ventilating fan. I've got two computer fans that displace 78 cf per minute. With two going, I'm hoping it will keep the place pretty clear.

Does anyone see a real problem with this lack of insulation?

BTW: I'm in Central California, where the weather's very mild. No desert or snow camping anticipated.

[shil]

I see no problems with your plan. I used uninsulated 3/4" sides, a 5/8" uninsulated floor with a cheap inner-spring mattress, and 3/4" foam insulation on the 'curves'. No worries at all.

Why all the fans? Just crack a window.

[Dave Nathanson]

After spending several chilly summer nights at 8600 feet altitude, I now know that I should have insulated the teardrop. The walls & floor are 1" thick plywood, and the roof is 3/8". The whole exterior is covered with aluminum. We have a 1 foot square roof vent, and we've taken to using a square of that aluminized bubble wrap insulation to cover it on cold nights. It might help, but it's sort of hard to tell. The windows do get a lot of condensation, but the walls mostly don't. The interior is covered with 1/8" oak. It looks really nice. But it's COLD at night. When the temp dips under 45, I've been sleeping with my fur "mad bomber" hat on and the sleeping bag all drawn up tight. It's just not warm in the TD, like I thought it would be.

Without insulation, it's no warmer than a tent!

I am now experimenting with fiberglass house insulation on the ceiling. It really helps a lot! I can get almost 2" of insulation, but the house insulation is difficult to tear thinner. It come way too thick! It's easy to separate, but almost impossible to keep a consistent thickness.

I have considered using rigid foam, but I don't see how that would work out well for the front curve. So my current plan is to look for some thinner flexible insulation. The higher R value, the better. But even with flexible insulation, it's not going to quite work out the way I want. We have an "open beam" look, and I want to keep that look. So I'm thinking of cutting the insulation to fit between the beams, so you can still see at least a little of the beams. but covering that with oak will probably lose the cool curve look inside. :-(

So far we have never needed the fan, which is good, because that thing is way too fast, and way to noisy. If we do need it, I've got a 12v motor speed controller to tone it down. Even with the insulation in the roof, on cold nights we get a lot of condensation on the windows.

[Arne]

If I wanted an open beam look, I would just attach them on the interior of an insulated ceiling after I was done.... just like they fake it in houses.

I have 3/4" foam in the walls and would go double that if building a new one... right now, I have 3/4 in the ceiling and would probably increase that, too... it just isn't that hard to insulate. and I think the walls don't weigh much more, and are more rigid.

It's nice to see things come together quickly, but if a trailer is going to last for years, it pays to put in the time up front to get the enjoyment out of it you want.

No lying in bed freezing your butt each night thinking, "yea, but I got it built fast....."

[Q]

Anyone ever try that aluminumized shiny buble wrap stuff for insulation? It would be easy to cut pieces that could be pushed up between the beams and hung on the walls for winter use, then quickly removed for summertime.

Q

PS: I don't need no stinking insulation with my forced air furnace, I can warm the whole campsite with radiated heat from my teardrop.

[mikeschn]

PS: I don't need no stinking insulation with my forced air furnace, I can warm the whole campsite with radiated heat from my teardrop.

Q,

You're so funny!!! How big was that tiny little forced air furnace of yours again? I've got the 12000 btu one! I have (2) 20 lb bottles on it... that should last a while, ya think?

Mike...

[Joanne]

I was watching a home improvement show one time and the guy was using an electric knife to cut the fiberglass house insulation with. You might be able to use one to achieve your consistent thickness.

Joanne

<snip>

I am now experimenting with fiberglass house insulation on the ceiling. It really helps a lot! I can get almost 2" of insulation, but the house insulation is difficult to tear thinner. It come way too thick! It's easy to separate, but almost impossible to keep a consistent thickness.

<snip>

[DANL]

Here's a thought. In order to use foam insulation in curved areas like the front and ceiling, try using the 1/4 " thick fanfold insulation that is used under aluminum and vinyl re-siding jobs. I did this on one of my projects and it worked fine.

The 1/4" thickness will take quite a bend. Granted, you will have to build it up in layers but that isn't too difficult. I didn't even glue mine in place. I cut it for a friction fit and just used a few brads into the stringers/ribs to hold it in place until the interior paneling went on. The inside panels and outside skin keep it in place just fine.

Another nice aspect is that you could use it for walls with thinner insulation space--'course the more insulation the warmer/cooler the tear will stay.

Hmmm. I just did a test and find that, in one of its directions, it will bend to a six inch radius without breaking.

You can get it at Home Depot and I'm sure any big name home improvement store would have it. Might be worth a try.

[Arne]

My roof ribs are 12" o.c. I used ripped 2x4's for the ribs. That gave me a 1.5 inch space. I put rigid 3/4" foam pieces in the spaces and went around the gaps with aerosol foam... there are spaces, but everything is sealed up so tight, I'm not concerned about any condensation...

I think rigid insul could be kerfed to make the bend... if necessary.

[Dave Nathanson]

I was watching a home improvement show one time and the guy was using an electric knife to cut the fiberglass house insulation with. You might be able to use one to achieve your consistent thickness.

Joanne, that's a veddy interesting idea! I'll have to ask around and see if I know anyone that still has an electric turkey carver from the 70's.

I have some of that aluminized bubble wrap that is sold as a water heater cover. It's definitely bendable; it comes on a roll. But I suspect that it's a better reflector than an insulator. Can it possibly have a better R value than the same thickness of fiberglass house insulation?

I've have a real time of it, trying to figure out R values. Seems that the reference materials I find don't quite match the materials that I can buy, or consider using. Case in point, the house insulation has a pretty good R value. BUT they are considering it at full thickness, which I don't have room for. The aluminized bubble wrap had some notation about it working better in a certain orientation versus the heat source, and how it was a good reflector. Wellll, If I don't have a heat source, and I want to put the stuff above me, then they don't offer that data. I was also unclear about what happens if you use 2 or 3 layers of that bubble wrap. Does that make the R value double or triple? Even when I do find some info, I can't be sure if they are talking about the same stuff that I see in the local Lowes or Home Depot. It's all so vague.

Here's an early photo of the inside, before the front window went in. See the green beams & the curve? Well I like those both.
Now it looks more like this
The part about Retrofitting insulation that I still can't figure out:
Even if I cut the insulation to fit between the beams and get the insulation to bend around the front interior curve... How can I cover that with 14" x 5' wide pieces of 1/8 oak without losing the curve? It seems to me that oak piece that short (12"-14") won't bend. So they will just be rectangles and I'll end up with a hexagon instead of a curve. Or something with corners anyway.

Just trying to keep the "classic styling" I already have, but without the shivering part. And I'm open for any & all advice.

[Q]

http://www.reflectixinc.com

I'll bet the bubble wrap insulation would do a pretty good job in a teardrop, especially if you could leave it exposed on the inside. Ever try one of those aluminized mylar emergency "space blankets"? They really work. Might also work as a ceiling mirror for the little love nest.

Also, I don't remember what the BTU rating is on my forced air heater but it's about 20 times more than needed.

Q

[WarPony]

Hey Q, I brought up the refectix (foil-covered bubble wrap) insulation subject up a couple of months ago and got good input. I was thinking (and still do) that the foil is the best reflector for heat, both inward and outward but the strength of bonding the foam to the walls is more benifcial. The thing about the emergency blanket is that is only used in a last ditch effort to keep warm. The moisture from perspiration and respiration will only build up on the surface of the inside and run down to the floor of the trailer and cause more problems later on.

[andysbunny]

I just used the bubble wrap insulation for the door on my garage. It has really helped keep the heat in from my Kerosene heater. I have a thermometer on the wall in the garage. Before the door was insulated (just the walls were at the time, no windows and attached to the house.) I would go out and it would be 20 outside, 35 in the garage. After the bubble wrap insulation was put in the doors, I would go out and it would be 45 - 50, and after 30 min with the heater on low, it would be 65 -70.

I think it would be great for an afterthought insulator.

I still think that I will use foam in the walls and ceiling, but possibly make a ceiling "blanket" from it for cold weather camping.

Dawn

[Dave Nathanson]

I checked out that website: http://www.reflectixinc.com/ It's quite interesting. A couple of things elude me though. They keep talking about how this thin aluminized bubble wrap can reflect up to 97% of radiant heat. Is that relevant for an unheated teardrop trailer? They say that radiant heat travels at the speed of light, and I don't think we have that. Just the ordinary heat that leaks out around the edges the sleeping bags.

Q, you mention it might be important to not cover this material. That seems odd to me, as more insulation would seem to be better, but then again, if it's a reflective sort of thing, then I could be talked into believing that it's important to allow the radiant heat to bounce off it's surface.

I was encouraged a bit by the reflectix website mention of keeping ice cold longer than 3/4" of EPS insulation, whatever that is.

Any idea of how this stuff would compare to an equal thickness of fiberglass house insulation? I have slightly less than 2" to work with.

[Dave Nathanson]

hi Dawn,
Thanks a bunch for your explanation of how the bubble wrap stuff works for you on your garage door! How thick is it? One layer or two?

I can see that it made a huge difference! What kind of heater do you use? Is it radiant heat of some kind?