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C Johnson · 04-23-2005, 12:19 PM

Hello all ! I am in need of some advice on what kind of insulation to use to replace the old mouse house that I have now. Under the floor I think something that won't soak up water would be a good idea. Otherwise I am open to any suggestions. Goin out to work on the "ol aluminum bank".

Ken J · 04-23-2005, 12:39 PM

FWIW - I didn't replace the insulation in the belly on my trailers at all. To me all they do is collect mosture and make great homes for rodents.

I know that most do replace however - everything from fiberglass to that blue insulating board.

Ken J

malconium · 04-23-2005, 12:46 PM

I am going to install hot water radiant heating on top of my Polyboard floor. Because of that I decided to install reflective foil insulation on top of the floor (and under the radiant heating pipes). Otherwise I would have used the foil underneath the floor. I would have figured out a way to mount it about 1" below the floor so that both sides have an air gap. I liked the thought that it would not be able to soak up moisture and would not be all that usefull to rodents as nesting material.

Malcolm

Tinsel Loaf · 04-24-2005, 12:37 PM

How about a shot of expanding foam insulation from a can.

87MH · 04-24-2005, 06:19 PM

I´m with Ken J on this one...

The type of camping I do does not require floor insulation....

On the canned foam thing - too much would be a really bad thing, also, most closed cell foams eventually absorb some amount of water, and most importantly - it´s a real beeatch if you ever try to remove it...I´ve had to cut some out before...cussed the installer.

One plus on the canned foam - it works great for the uses it was designed for - getting into hard to access places to close off öpen¨areas that should be sealed to prevent airflow and/or drafts.

Tinsel Loaf · 04-24-2005, 07:29 PM

Thanks Dennis. Good info, I'll stay away from the can foam. Sounds like it has to many drawbacks.

LowellN · 04-24-2005, 07:33 PM

I'm in mid process of replacing the floor, and repairing the frame in the front 8 feet of my 1975 Sovereign. The frame is now repaired and the new belly pan is on (too bad that shiny new 2024T3 is where nobody can see it!) and ready for floor. I layed some thick plastic on top of the new pan, then I insulated the around the belly pan/banana wrap, next to crossmembers, and around the front hitch A frame with the expanding foam. Then I cut the pink R board to fit in the spaces between crossmembers/outriggers and am going to shoot a little foam between them and any other gaps. The foam and the R board will not absorb water and will protect the frame from future water (I think I have all the leaks stopped for now) seepage. It should last another 30 years (I'm only 24, so I might own this trailer for that long

) if I keep her watertight.

Lowell

58BUBBLE · 04-24-2005, 08:34 PM

I just finished mine and used the factory method. The professionals I talked to said that using fiberglass insulation was definently the best way to go. They said to use 3" non-faced insulation. Since I could not find that I bought the closest thing to it which was 3.5" faced fiberglass. I pulled the paper backing off along with .5" of insulation to make it 3". I'm about done installing elevator bolts and the floor is very nice to walk on, feels solid and well insulated. I almost went with the foam board but in the end changed my mind because there seemed to be question as to it being able to hold up to the vibrations in a trailer. The original insulation job has lasted almost 50 years and is still working so I decided to replace it the same way.

uwe · 04-24-2005, 10:05 PM

I used reflectix aluminum bubble foil insulation inside the walls, and 1" closed cell foam under the floor.
I went by Malonium's method, with closed cell foam spacers between the outer skin and the foil. I applied the closed cell foam with construction adhesive directly to the bottom of the floor from underneath. So far I am happy with my choices. It is certainly a clean way to insulate a trailer.
I firmly believe that fiberglass insulation will cause frame rust and also offers great shelter to rodents and insects. Done 2 trailers, and ran into the same issues with both of them.

fireflyinva · 04-24-2005, 10:10 PM

58 Bubble-

Did they say why they recommended fiberglass? FWIW, we started tearing our trailer up this weekend. Generally, we found that in most places, our vintage (about 45 years old) insulation batting is in surprisingly good shape. In one area, fluid from a battery leak collected. There, the batting disolved, along with the steel frame members...

We are thinking of replacing the batting between the floor and the bellypan with rigid foam insulation, for sake of added water resistance. Curved surfaces--like the wall, will get replacement batting...

Or at least that's our plan at this point.

Mary

C Johnson · 04-24-2005, 10:32 PM

Nice blog !

3Ms75Argosy · 04-24-2005, 11:09 PM

Just saw your gut job in the photo section. Wow! You've really started it. It think your AS will be as good as new when you're done. Keep us informed!

As far as insulation, I think something that will let our floors breath here in the wet Northwest would be great. I like the idea of sprayed in foam, but worry about water vapor being trapped between the floor and the foam, causing rot. However, Janet and Gary used spray foam (I believe) and haven't had any problems. I just hate the idea of the fiberglass. I too am worried about "visitors" living in it. The foil bubblewrap insulation seems neat also.
Let us know what you decide.
Marc

Janets Husband · 04-24-2005, 11:26 PM

Quote:

Originally Posted by 3Ms75Argosy

Just saw your gut job in the photo section. Wow! You've really started it. It think your AS will be as good as new when you're done. Keep us informed!

As far as insulation, I think something that will let our floors breath here in the wet Northwest would be great. I like the idea of sprayed in foam, but worry about water vapor being trapped between the floor and the foam, causing rot. However, Janet and Gary used spray foam (I believe) and haven't had any problems. I just hate the idea of the fiberglass. I too am worried about "visitors" living in it. The foil bubblewrap insulation seems neat also.
Let us know what you decide.
Marc

The foam has been in a year now without problems. Easy to use but rather expensive in compairison with the other types of insulation.

C Johnson · 04-25-2005, 12:55 AM

I am still thinking about this and will do some investigating at HD. I know that I prefer not to use the same type of fiberglass if I can help it. I just took off the old stuff under there today. Lets see..hmm.. how many dead mice can one trailer have in it anyway ? what a mess. I do plan on using the AS during the winter months, taking it up skiing for overnights and to the coast etc. so I want something under there. I was leaning to the closed cell foam board. But, I wonder about it wearing out from the natural movement of he AS.

The tops of the frame rails are rusted, while I still have black paint on the sides. Seems the fiberglass held the moisture against the steel.

PS - my coach was, at one time, totally infested with mice and had to throw away most of the insulation. I will be putting the original type back in the inside walls.

Chris

C Johnson · 04-25-2005, 01:03 AM

Thanks Marc, I had to do it. Too many issues not to go this route. If I knew this was going to turn into this kind of a project I would have left it on the lot. The Caravel has been neglected for a very long time. No way to see some of the problems I have found though. I will have a very nice comfy AS when I am done, however. :-)

58BUBBLE · 04-25-2005, 10:40 AM

I was told that rigid foam would not withstand the vibrations in a trailer. I know some forum members are using it so maybe in 20-30 years we will have better statistics than we do now about how true that really is. Anyway, when I removed my floor I was pleasently surprised at how well my original insulation has held up over the last 50 years. I had no signs of rodents or problems of the insulation holding water. My frame was in pretty good shape other than a couple cracked welds which I don't think had anything to do with the insulation. Bottom line- make sure you go over your entire unit with a fine tooth comb and make sure any and all possible leaks are sealed. One more reason I like the fiberglass system is it will be a better sound barrier than the foam board. I plan on rodent proofing my bellypan before I'm done to be sure I don't have any future problems that others have had.

Quote:

Originally Posted by fireflyinva

58 Bubble-

Did they say why they recommended fiberglass? FWIW, we started tearing our trailer up this weekend. Generally, we found that in most places, our vintage (about 45 years old) insulation batting is in surprisingly good shape. In one area, fluid from a battery leak collected. There, the batting disolved, along with the steel frame members...

We are thinking of replacing the batting between the floor and the bellypan with rigid foam insulation, for sake of added water resistance. Curved surfaces--like the wall, will get replacement batting...

Or at least that's our plan at this point.

Mary

fireflyinva · 04-25-2005, 12:54 PM

That's something to think about. It appears to be a bit of a toss up. What about a hybrid--foam on a cushion of fiberglass? hmmm....

I'm happy to say, we haven't found rodent signs so far. There are two small gashes in the bellypan, probably caused by rocks. As a temporary move, I sealed these holes with expanding foam, which was advocated on some cable home improvement show as a stopgap against rodents (for houses). We've been out with it for a year, and the foam seems to have stayed put--and there's no sign of rodents, either. It's a bandaid solution, but it seems to have worked ok.

Mary

58BUBBLE · 04-25-2005, 01:08 PM

When I 1st got mine about a year ago I also used expanding foam to seal the bellypan. I've seen other threads that say not to completely seal the bellypan so I am going to figure out someway to make it rodent proof and still be able to breath. I'll probably end up using some kind of screen material or similar. Good luck on your research and keep us posted as to what you decide to go with.

malconium · 04-25-2005, 03:54 PM

I am sure that installing fiberglass insulation is by far the easiest way to insulate. The stuff is flexible and compressable making it easy to fit into unusually shaped cavities without having to take all that much care in cutting it. It is in fact so compressable that you can lay it across the frame members and install the floor on top of it. My guess is that particular factory technique was more motivated by ease of installation than by any other reason. The fiberglass itself does have the advantage of being water proof. My fiberglass insulation was actually in pretty good shape in general but did appear to have contributed some to frame rust in areas where the insulation had trapped moisture. Overall it is not all that bad of a choice if you can keep the rodents out and keep things more or less dry. It does provide reasonable levels of insulation for an RV.

C Johnson · 04-25-2005, 08:39 PM

I can't find it now, but someone on here used these small aluminum vents to allow the belly pan to breathe. They were round and had screen on the backside.