Fiberglass Insulation

[roadinspector]

I just want to stir the pot a little. The discussion about which insulation to use has been discussed many times. Rightfully so, some form of board insullation has been the direction folks have been advised to use. The reason fiberglass has not been suggested to use is that the batting tends to seperate and go to pot. I agreed until I saw what I found in my old 92 donor trailer. I pulled the reefer out of its hole and it had factory installed fiberglass insullation on both sides of it. It was probably 1 1/2" to 2" thick. I was very surprised to see that it was in good shape. There was not any seperation in the batting at all. I will still advise folks to use the board but if budget constraints is an issue, I now do not see any reason to not use fiberglass batting. After seeing this, I probably would have used it in the walls if I didn't have my free foam board.


What do you think?

Earnest

[crumvoc]

Some time ago I came across a youtube video about how airstream insulates its trailers... With fiberglass insulation. They spray an adhesive into the shell of the trailer then take large batts of fiberglass insulation and apply it to the adhesive. It seems that it works for them. One thing to consider is whether the shell of an airstream is more watertight than a cargo trailer. Probably is.

[KevinC]

I wondered about that. I was thinking of using fiberglass in a teardrop so it would be easier to go around the curves. I thought it might tend to mould though. Did you find any of that?

[DTCOOPER]

The majority of R factor in fiberglass insulation is in the "air space" that the batt creates. I believe you'd severely limit the R value.

[Shadow Catcher]

When you look at what fails in an RV it is usually the two R's, rot and rust, in that order. Fiberglass bats will sponge up water and keep it in contact with wood and metal. If a path for moisture to evaporate is provided that would not be a big problem for fiberglass bats. However the wall board used in most RV's is vinyl covered Luann and if you use plywood of any sort it can't breath and if it is coated with most anything it really will not breath at all.
The R value does not appear to be a big factor other than wet fiberglass conducts heat/cold well.

[KevinC]

Good points. Sounds like using fiberglass may not be the best choice overall. Thanks for your input!

[roadinspector]

Thanks guys for your input!! I enjoy constructive dialog to learn from and get multiple opinions.

There were no signs of mold, rot or rust in this location. It did have fresh air ventilation from the reefer vents. One at the base and a roof vent as RV reefers need. The two walls that it rested against were interior paneling on both sides. There was no sign of moisture ever getting to these panels. It was just dirty from years of being in place and dust coming in thru the vents. The roof on this trailer is shot! Like shadow catcher said, rot and rust in that order. Rot had killed my trailer. The reefer area is about the only place I don't have any water damage. There has been several inquiries on the subject matter of CTs leaking and it has been the general consensus that they don't. That is one of the reason for the CT conversions is that they are better built.

Now there is no way I personally would have chosen fiberglass batting over my foamboard. I would just like to state that if faced with wanting to build a seriously tight budget CT and you have access to fiberglass batting, it can be used. There has been some excellent informative discussion on this. Thanks again guys!! Does anyone else have any input?

Earnest

[Mud_Bug]

I have recently insulated my CT. In the beginning stages of planning my build I was looking at all alternatives to insulation. Cost, effectiveness, supplies on hand, and longevity of material used were all considered.
Cost: I found several different ways to get this task done. After reading and reading, investigating and probing...I found that to me, my best option was to use foil back foam board. Rust and rot were no where in my thought process until now. For $145 I purchased 15 sheets of 1" foil backed styrofoam insulation. Yes, it filled the z metal to its fullest.
Effectiveness: I wanted my build to be effective, practical, and go for "the long haul". In other words, I didn't want to have to re-insulate at a later date because I didn't do it correctly or cheaply. My supplies on hand were minimal, therefore I'm having to buy as I go to get this done. Again....cost on this build is a huge factor to me.
After reading this article, among many others, I'm tickled pink to know that my decision to use foam board will suit my needs very very well, I know it's done "right", and I will not have to worry about it again.

[KevinC]

I have recently insulated my CT. In the beginning stages of planning my build I was looking at all alternatives to insulation. Cost, effectiveness, supplies on hand, and longevity of material used were all considered.
Cost: I found several different ways to get this task done. After reading and reading, investigating and probing...I found that to me, my best option was to use foil back foam board. Rust and rot were no where in my thought process until now. For $145 I purchased 15 sheets of 1" foil backed styrofoam insulation. Yes, it filled the z metal to its fullest.
Effectiveness: I wanted my build to be effective, practical, and go for "the long haul". In other words, I didn't want to have to re-insulate at a later date because I didn't do it correctly or cheaply. My supplies on hand were minimal, therefore I'm having to buy as I go to get this done. Again....cost on this build is a huge factor to me.
After reading this article, among many others, I'm tickled pink to know that my decision to use foam board will suit my needs very very well, I know it's done "right", and I will not have to worry about it again.

I am thinking of using the same thing. It seems to be fairly cheap and looks like it would flex better around the curves of a teardrop. I may be wrong on the flex thing especially if you are using the thicker sheets like 1" or more. I thought of using several layers of the thinner stuff to help fit the curves.

Sorry... I am sure the flexibility issue is probably addressed in other threads. I have not researched it a lot because I am not that far into my build.

Thanks for your thoughts.

[roadinspector]

I have recently insulated my CT. In the beginning stages of planning my build I was looking at all alternatives to insulation. Cost, effectiveness, supplies on hand, and longevity of material used were all considered.
Cost: I found several different ways to get this task done. After reading and reading, investigating and probing...I found that to me, my best option was to use foil back foam board. Rust and rot were no where in my thought process until now. For $145 I purchased 15 sheets of 1" foil backed styrofoam insulation. Yes, it filled the z metal to its fullest.
Effectiveness: I wanted my build to be effective, practical, and go for "the long haul". In other words, I didn't want to have to re-insulate at a later date because I didn't do it correctly or cheaply. My supplies on hand were minimal, therefore I'm having to buy as I go to get this done. Again....cost on this build is a huge factor to me.
After reading this article, among many others, I'm tickled pink to know that my decision to use foam board will suit my needs very very well, I know it's done "right", and I will not have to worry about it again.

I am thinking of using the same thing. It seems to be fairly cheap and looks like it would flex better around the curves of a teardrop. I may be wrong on the flex thing especially if you are using the thicker sheets like 1" or more. I thought of using several layers of the thinner stuff to help fit the curves.

Sorry... I am sure the flexibility issue is probably addressed in other threads. I have not researched it a lot because I am not that far into my build.

Thanks for your thoughts.

KevinC,
I do like your idea of multiple thin layers for your purpose.

Earnest

[hankaye]

Howdy All;

I have recently insulated my CT. In the beginning stages of planning my build I was looking at all alternatives to insulation. Cost, effectiveness, supplies on hand, and longevity of material used were all considered.
Cost: I found several different ways to get this task done. After reading and reading, investigating and probing...I found that to me, my best option was to use foil back foam board. Rust and rot were no where in my thought process until now. For $145 I purchased 15 sheets of 1" foil backed styrofoam insulation. Yes, it filled the z metal to its fullest.
Effectiveness: I wanted my build to be effective, practical, and go for "the long haul". In other words, I didn't want to have to re-insulate at a later date because I didn't do it correctly or cheaply. My supplies on hand were minimal, therefore I'm having to buy as I go to get this done. Again....cost on this build is a huge factor to me.
After reading this article, among many others, I'm tickled pink to know that my decision to use foam board will suit my needs very very well, I know it's done "right", and I will not have to worry about it again.

I am thinking of using the same thing. It seems to be fairly cheap and looks like it would flex better around the curves of a teardrop. I may be wrong on the flex thing especially if you are using the thicker sheets like 1" or more. I thought of using several layers of the thinner stuff to help fit the curves.

Sorry... I am sure the flexibility issue is probably addressed in other threads. I have not researched it a lot because I am not that far into my build.

Thanks for your thoughts.

KevinC,
I do like your idea of multiple thin layers for your purpose.

Earnest

If I remember correctly, back in the late 70's and early 80's, when folks were doing Van conversions they would 'score' the thin plywood on one side so that they
could bend it into sweaping curves. By scoring you are removing a small amount so that when you bend it it has somehwere to go sorta relieving the
pressure so it won't break... Worth a try ....

Also I was thinking of going with the fiberglass 'Pink' stuff, haven't made up my mind ....yet.
I'll let ya know what I find out.
I did just send the following inquery to Owens Corning;
How to insulate a Cargo Trailer.
I am thinking about converting one to a camper style trailer to use for weekends and perhaps
a week or 2 at a time. The walls are only 1" thick and I don't want it to have condensation form
when I'm sleeping and it's cold outside.
I live in the desert Southwest. New Mexico. But I'd be traveling up and down the Rockies so it may
be cold one day and hot the next.
What's your recommendation and why.
Thanks for your thoughts.

hank

[OverTheTopCargoTrailer]

Hankaye

Your the bomb

Oc has about 100,000 employees, did you remember to address your letter to the VP of cargo insulation ??
I can't wait to hear his response on how to insulate your trailer

If you want my 5 cents worth, then leave the plywood up, install your foam onto the plywood , floor, walls & roof
The more / thicker foam the better the insulation.
And put another layer of plywood - plastic to protect the foam board.

Jerry

[hankaye]

OTTCT, Howdy;

Just filled in the regular contact form for inquiries....
Reckon they'll be scratching their heads for a few days
before I get a responce... Let ya'll know what they say...
Also been lookin' into some of those 'reflective' types
for the roof as I'm in Southern N.M. (can ya spell HOT without
the sizzling noises ???)

hank

[OverTheTopCargoTrailer]

I had to crack up ...... Private joke
As I installed lots of insulation in Jimmy Carters time.

From what I know about OC .... They normally won't even piss on your shoe unless
You buy about 10 - 45 ft trailers full of their pink stuff in one shot !!
To them a $100,000 order is like you spending 99 cents at Mickey D's for some stuff.

I am having very good results with the 3/4" blue smurf board made by Dow Corning $15 at lowes.


Can't wait to see if you get a 10 cent response from OC

[adamhusband]

Having several layers of the thin stuff is what I initially did in my smaller build. I was not that pleased with it. The one thing I thought of after I had done all the panels was when I go to cut in a window hole it will be a little bit of a mess plus the single pieces gave me more stability in the walls. Now I know the bigger trailers have metal studs so that may not even be a consideration for you guys. Here are some comparison pics for you to look at. Hope it helps someone.


The other thing I noticed was keeping the materials in the panels was easier with the thicker material. You could glue or tape in place but the thicker material was easier for me.