Insulation with Reflectix

[action95]

Has anyone used Reflectix as their insulation? I have read that it can create moister, but that person was only claiming that the Reflectix company told her that. I am planning on putting Reflectix along the inside of the outer skin, and then putting Pink insulation over that. Does anyone have any reason that I shouldn't do this?

[drairstream]

Don’t compress the pink or it will lose its insulation value

[skyguyscott]

Yes, many have. You can search the forums on insulation installation; some have some very nice pictures. A broader search will reveal so many threads on insulation, you can spend the better part of the day reading them. There are several schools of thought with passionate advocates for each.

From what I gather, fiberglass is today perhaps the third or forth best method of insulation, due to it's propensity to hold water and provide nests for critters. Most say pick one method and don't mix fiberglass with others.

There are some who swear by newer closed cell spray foam, claiming it offers the best insulation for the cost, protects the inside of the outer skin from corrosion, and adds strength to the shell, all while being light-weight. Downsides seem to be that if you need to ever replace a panel, the foam makes it difficult as it's hard to remove. Early experiments with older foam formulations decades ago were unsuccessful as the road vibrations turned the foam to dust; a problem newer foams are said to have solved.

From what I read, Reflectix, properly installed, is pretty good at keeping the inside cool, but does not perform as well keeping the inside warm. See the threads on how best to install it with the proper gaps and air-tight seals. There is a foam cell reflective insulation alternative that also gives you better sound insulation than reflectix, evidently.

Timeless trailers uses a foam-core material they swear by.

Key issues no one has really fully solved yet regarding insulation of these aluminum trailers: the single pane windows and isolating the ribs from the skins; these two are the biggest culprits in thermal transfer, it seems.

That's the executive summary of my research, many others here with more experience will chime in; just be ready for lots of interesting discussion.

[action95]

Thank you for such a thorough reply. Do you know why most people say pick one method and don’t mix fiberglass with others? My thought being won’t combining reflectix and fiberglass only increase the R value?

[skyguyscott]

I am not an expert, but from what I gather, most that do reflectix do, in order from the outer shell: shell, foam spacers, refectix, spacer (run wire, conduit, etc.) another layer of refectix) spacer and inner skin.

Here is a link to a very thorough thread on a guy doing reflectix, read that and follow the links in that tread and you will be a lot farther along in understanding the trade offs and what others have done.

[TheGreatleys]

I did reflectix on the top half or so of my shell, attached loosely with double-stick tape, then rockwool. I couldn't tell you if the reflectix actually helped my R-value at all. My thinking was that anywhere my insulation fell away from my ceiling, the reflectix could take advantage of the void and add r-value. I think the main reason not to do it is it's probably not worth extra the money.

Moisture will not come out of nowhere, but it can condense on cold surfaces if you don't have a vapor barrier blocking air movement. I can see if you used reflectix only with spacers how the air movement might give you condensation problems, but you'd have to talk to someone who used that method to find out if it actually happens in practice. I think the inner skins themselves would be an adequate vapor barrier if you're using fiberglass or rockwool batts.

I'm a big fan of rockwool for the main insulation. Super easy to work with and makes a nice tight assembly, so you don't get the voids you do with fiberglass.

I think the biggest R-value improvement I made was adding a thermal break between the ribs and inner skins with foam tape, which helps prevent heat from conducting straight through the ribs.

[cwf]

You will have 'moisture'/condensation with any kind of insulation. We have had Reflectix in our windows and other places inside the AS and it has held up well. however, the rock wool may give you the best r factor.