7x18 Toyhauler - Deluxe Boondocker - National Forests only

[ZColorado]

Curious as to why the polyiso performance is not linear as the rest seem to be?

From what I have read it's all due to the "blowing agent" usually some form of HFCS or CFC. I've found a number of articles going into great detail about variations in that temperature tendency with different blowing agents. But apparently they start to condense and become liquid again at lower temperatures, thus reducing the R value.

[aggie79]

Great layout and execution! Thank you for the construction pictures.

[McDave]

Here is a bit more of the story behind that Dow graph. It seems that the "polyiso" tested was in fact roofing insulation, not wall panels. Not really an Apples to Apples comparison. Sometimes the devil is in the details.

https://sprinter-source.com/forum/showp ... stcount=42

Quote:
Originally Posted by Understanding Mean Temperature Phenomenon for Polyisocyanurate Insulations
"Although this graph includes many types of insulations--including polyisocyanurate foam insulation (shortened to “Polyiso” in the legend)--the type of polyisocyanurate foam insulation in the BSL Thermal Metric Project is only roofing Polyiso insulation, which is significantly different from THERMAX™ Brand Insulation, patented, designed and manufactured for wall applications. In fact, polyisocyanurate foams have a wide range of property variations as a result of varying/different proprietary formulations used by each manufacturer and for different grades of foam.

In Figure 3, the same graph has been altered to include the R-Value of THERMAX Brand Insulation at three different mean temperatures to show just how much the lack of THERMAX insulation data represents. This further illustrates how polyisocyanurate insulations can differ from one another. Wall-polyisocyanurate foams are designed to meet the fire and vertical application performance requirements through use of different chemical formulation, which inherently separates the Polyiso foam for walls from those used in roofs even if offered by the same manufacturer. The labeled THERMAX Brand Insulation R-Values are all above the 6.5 R-Value mark, significantly higher than the other polyisocyanurate insulations shown."


McDave

[ZColorado]

Thermax is DOWs proprietary Polyiso board. It's different then the stuff you buy at home depot. Notice the top line on the graph that is for their Thermax board.

The stuff you buy for your walls is the poorer performance stuff, UNLESS it's specifically DOW Thermax board.

[McDave]

Not ALL the stuff you get at Home depot is roofing insulation. In fact I doubt they sell roofing insulation as wall insulation at all. R-MAX comes in wall or roofing insulation for example. This comparison was for roofing polyiso only, whereas the Dow thermax was specifically wall insulation. Not really a fair comparison but it does make for high impact graphic.

McDave

[ZColorado]

Either I am completely misunderstanding your point or we are talking about different things.

That graph shows me that regular polyiso performs poorly under 45f. The DOW Thermax board does not. I am under the impression that all other non-Thermax boards perform poorly no matter if they are for roofs or walls. There are a lot more articles our there concerning Polyiso and this trait, they make no distinction on roof or walls.

Granted this is the only graph that shows Thermax specifically does not follow the trend, but that was not my point in posting it in the first place.

Am I crazy? or am I just not understanding your point?

[McDave]

No, Not crazy. I just took that info from that graph. This is the first I have heard of the polyiso breakdown. If you click the link you will see where I copied the quote and information about Dows graph. Here it is again, https://sprinter-source.com/forum/showp ... stcount=42
I would be happy to read any other sources of similar information concerning polyiso performing poorly below 45F. Here is what I saw when I looked at that graph. Dow graph with Dow product outperforming all other products. No surprise, it is a sales tool. On the graph is an un-named polyiso with an * next to it but no explanation. At the bottom is a disclaimer "data may not be representative of all insulation types". Ok that lets you pretty much get away with anything. And since each manufacture has their own proprietary recipes and ingredients and process grouping them all together as polyiso and attributing this trait to all seems less than what I would call gospel. Then we learn that the test was with an un-named roofing polyiso which is yet another blend, different than wall poly, made for a different purpose but used to compare to Dows wall polyiso Thermax, that doesn't suffer from the dreaded polyiso breakdown because all polyiso is flawed except dow polyiso thermax.
I understand you are not pushing the Dow product, you just used the graph to make your point as to why you went with xps. But if that graph had shown polyiso to behave in a linear fashion as ALL the others did, would you have made a different choice? I don't mean to lay my doubts about this info at your doorstep, and I apologize if that is how I came across. If after reading the info attached to the SAME graph in the link I provided you don't have some doubts, I may be crazy. Or just wrong. Wouldn't be the first time. Having said all that, I can say that I have used polyiso in all kinds of conditions and have never witnessed any type chemical condensation or performance loss at any temp. with any brand. Then again, I just use the stuff and I am not a lab tech or chemical engineer.

McDave

[ZColorado]

Ah, ok. I understand now. Thank you for that clarification.

But if that graph had shown polyiso to behave in a linear fashion as ALL the others did, would you have made a different choice?

Yes, if polyiso was not temperature dependent I would have used it. It markets itself as a highest R-value/thickness product. Price is comparable to XPS so why not.



Here is another non-DOW article on the issue. This was the first one I saw about it. That Dow graph was just the prettiest.

(Article looks to be behind a paywall now. But the intro says enough.)

https://www.greenbuildingadvisor.com/ar ... -beats-r-6


here is another one.
https://www.energyvanguard.com/blog/594 ... a-Constant

and another
https://www.buildingscience.com/documen ... nt-r-value

[McDave]

Hey ZColorado,
Thanks for the info. I just lightly skimmed thru it but I will go more in depth asap. Winter finally arrived here and we have been -29f lows and -22 highs. When it that cold you have all sorts of things go wrong from cars that wont start to river ice jams that cause flooding and taking care of the livestock. Plus it is hard on old bones and you cant move all that fast and you can only be out in it for short periods. So it has been crazy here but it is supposed to warm up next week and I hope to get caught up and have some time to digest those articles. I did notice they talk a lot about the mean temp being a issue as well as water /vapor barriers and the fact that in some samples the iso gasses had migrated and were replaced by air. These were aged 15yrs but I can see how that could be a bad thing. What I haven't seen is a bunch of class action litigation. There is a ton of polyiso marketed and sold in places where we dream of having 45f for six months of the year. Then again these test are assuming the polyiso is to be used as exterior sheathing, not the way we use it in CTCs as wall fill or interior insulation. That may negate the issue from the temp stand point, and I noticed that one of the test companies suggested that to compensate a person should just assume R5.5 as R5.0. So still a significant loss of 10% but not a disaster.
Thanks again,

McDave

[ZColorado]

Coronavirus update:I took a long break working on the trailer over the fall and winter. Now that it's spring time I've been getting itchy to get out camping so I've been working on the trailer again. I accomplished a few things that I wanted to share.
#1 - Installed my Aleko Motorized awning. One of the gas struts is weak, hopefully they replace it for me. The whole thing is held up by the force of those struts so they are important. Otherwise I am happy with it. I welded in some 2x1 16ga tube inside for the arms to mount to. It's very stout. I have not wired it in yet. I've decided to re-do my wiring to an industrial DIN rail mounted terminal block like I am familiar with at work.
#2 - Installed my spare tire mount. I purchased a heavy duty stake pocket tire mount and cut it. I went to the steel yard and purcahsed some 3x1.5 11ga tube and made a stout mount for it over my battery box. https://www.amazon.com/gp/product/B081TQC36P
#3 - Installed my front Maxxair fan, I have one in the rear, but this was for the bathroom. Jigsaw is the way to go.

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[flboy]

Coronavirus update: I've been getting itchy to get out camping so I've been working on the trailer. I accomplished a few things that I wanted to share.
#1 - Installed my Aleko Motorized awning. One of the gas struts is weak, hopefully they replace it for me. The whole thing is held up by the force of those struts so they are important. Otherwise I am happy with it. I welded in some 2x1 16ga tube inside for the arms to mount to. It's very stout. I have not wired it in yet. I've decided to re-do my wiring to an industrial DIN rail mounted terminal block like I am familiar with at work.
#2 - Installed my spare tire mount. I purchased a heavy duty stake pocket tire mount and cut it. I went to the steel yard and purcahsed some 3x1.5 11ga tube and made a stout mount for it over my battery box. https://www.amazon.com/gp/product/B081TQC36P
#3 - Installed my front Maxxair fan, I have one in the rear, but this was for the bathroom. Jigsaw is the way to go.

IMG_0463 (1).jpg

That is a fine looking trailer. Outstanding work.

Have to let us know how the Alekp holds up. I have the Aleko manual awning and like it very much. If I ever need to replace... thinking about the upgrade.


Enjoy camping in the trailer!

[Augie Dog]

Did you end up using the Liftco murphy bed from RVbusparts? It appears you did and in fact you are using the side lift instead of end to end lift. Is it queen size and how difficult was it to install. I have an 8.5 X 6.5 x 18 and want to locate a side lift on left or right side over inner wheel wheel mid length of the trailer.

[ZColorado]

I did use the Liftco. When you order they ask what orientation you want. It looks well designed but the aluminium frame is a bit flimsy and they cheaped out on the fancy bushings for the sliding mechanism It's just metal on metal. Install was straghtforward. I had made sure the legs mounted into a solid wall stud. I did take the extra effort to weld in extra support and tie in the neighboring wall studs. Might not be necessary, but it was easy for me. I also switched to 3/4" plywood top and it was much better than the 3/8" leftover wall panels I started with.

[Augie Dog]

I did use the Liftco. When you order they ask what orientation you want. It looks well designed but the aluminium frame is a bit flimsy and they cheaped out on the fancy bushings for the sliding mechanism It's just metal on metal. Install was straghtforward. I had made sure the legs mounted into a solid wall stud. I did take the extra effort to weld in extra support and tie in the neighboring wall studs. Might not be necessary, but it was easy for me. I also switched to 3/4" plywood top and it was much better than the 3/8" leftover wall panels I started with.

Good deal that is encouraging to hear. I was going to do an end to end but decided not to spend additional money to extend height. I really wanted a bed me and the wife can get in and out from our own side instead of crawling over each other and ease of changing bed sheets. I'm not getting any younger and just looking to the future! Lol

[ZColorado]

Another update. I've been in a big push to get ready for a big 4th of July trip.

- Liftco bed. I upgraded the aluminium tubes, I noticed that all of them were bent and it had only been me sleeping on it. I went to the local aluminium dealer and purchsed 1x1.5 tube that was much thicker. It's a whole new bed frame now. The hinge still needs some form of bearing but it's not a trampline anymore.

Tube Thickness

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-Awning - I called Aleko about the failed gas strut out of the box. The first time I called they said they would "ship out the part tomorrow" well that was apparently a lie. I had to call again 2 weeks later and wait on hold to talk to someone since they never answered my emails. In fact the only way it worked was to facebook message them and they called me back. a few days later I got two whole arms in the mail. WHOA. All i needed was the 26" long 150lb gas strut (Solera awnings are damn near identical to this one)
-Also had a scary incident driving down the road where the bolts holding the awning tube to the rail fell out. Not fun looking in the rear view mirror and seeing one of the arms fully deployed while traveling down the highway.
-Lights, I noticed that the fabric mounting strip had a slot that was the perfect size for strip lights, so I got some and wired them in, very happy about that.

Awning Lights

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-Morryde steps - I wanted some stout solid steps and Moryde had some quick disconnect steps that fit my needs (stout, does not reduce ground clearance, does not block the door when stored) installation was a breeze since the frame rail is directly below my RV door I installed and I am very happy with these. Downside is storage while traveling. They stairs are large, aluminium and sheet metal makes them light, but not that light.

Morryde quick step

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