Sprayed Foam and CTs...

[GPW]

Waay back in the late 70’s we were doing Van conversions , and on some DELUXE jobs we had the inside of the vans sprayed commercially with foam insulation ... The real advantage , besides the insulation was it consolidated the whole structure making it quiet, leakproof (not that vans leaked ) , and just SOLID!!! Anybody had this done to a new CT ??? Seems like a great idea...

[rowboat]

There's a place in my area (WA state) that does spray foam insulating.
They showed me pix of how they did this to their own cargo trailer
which they use for camping/hunting. They removed the interior plywood
and sprayed the interior, then put the trailer up on a ramp and sprayed the
underside. Claimed that now, once you get the interior warm, it stays that way,
hardly needing to run the heater.

Music to my ears, as to me the most important motive in wanting to camp
in a cargo trailer conversion is because I've read that few "real" RVs are
actually insulated enough to be used four seasons.

Furthermore I've spoken with an RV tech (not in the emply of the foam place)
who says spray foam is the best way to go.

My only hesitation about spray foam is that I've found websites complaining
about the reaction people had. Evidently some people are sensitive to the
chemicals even after the foam has cured.

Also spray foam is costlier than foam panels.

Would like to get some feedback on this method of insulating a CT.

[GPW]

Row , the trick we used to contain the cost was to go to a job site where they were already spraying ... since they were set up , we were able to get it done rather cheaply (side job)... as I recall , ~ 200USD , but that was back in the late 70’s ... We’d have everything taped off ready to shoot ... pretty quick process ... Really made everything SOLID and Quiet ... On a CT , should eliminate all that skin wrinkling too...

Ps . the only thing we didn’t spray was around the taillights ... left open inside for access later , should the need arise ...

[BC_Explorer]

I looked into having my CT spray foamed and after speaking with several knowledgable people, I decided not to. In general, if you plan on using your CT for on-road use only then spray foam is fine. However if your CT is going off-road (which my CT will), meaning forestry roads etc, then spray foam is not the best solution as the thin outer trailer wall panels will flex somewhat which can cause permanent distortion/creases in panles if the CT flexes enough as they are now too rigid with the spray foam applied.

Also if your CT ever develops a leak, which some people here have had, (including me, which was fixed by the dealer), removing out that sprayed in insulation to find the source of the leak will be quite the task...

[GPW]

Foam properly sprayed should Prevent any leaks , but then again we don’t go down forestry roads with a trailer made for the highway ... Seems you’d need a special kind of CT for that ...

[BC_Explorer]

Foam properly sprayed should Prevent any leaks , but then again we don’t go down forestry roads with a trailer made for the highway ... Seems you’d need a special kind of CT for that ...

I don't wish to derail the OP's question but one related comment. Spray foam alone will not prevent leaks in a CT or a house...even if properly applied. Would you apply spray foam to an entire CT then remove any factory caulking, silicone etc and hope that the spray foam does not allow any water penetration at all?

As to the off-road capabilities of CT's. There are a lot of people in this area that do take their CT's off-road in both summer and winter. The most typical use is hauling snowmobiles, motorcycles, quads etc. Just keep in mind that there is a difference between taking a CT on a forestry road as compared to taking a CT on an off-road trail...

[8ball_99]

I also pull my cargo trailer on dirt roads and gravel back roads. Some of the roads are very narrow so there is plenty of times mine has to go off the shoulder. This is why my trailer has straight axles vs Drop axles. No reason at all why you can't take a cargo trailer off paved roads if you have the ground clearance.. One of the main reasons I bought one was because of the extra strength of the steel framing.

As far as the spray foam I wouldn't do it to mine. Couple reasons. First and for most I'd be worried about the skin on the trailer. The skin shrinks and expands depending on temperature. The skin is thin aluminum and most trailers have steel frame. So the skin does not move at the same rate the trailers frame work does.. Thats why you knotice a little extra slack in the skin on a hot day. This is normal. To me I would think the spray foam would cause bulges in the skin or worse when the skin tries to expand on a hot day maybe the foam would stick and hold some of it but not all of it so you would end up ripples in the skin.
The other reason would be if you ever needed to replace a piece of the skin it would make life harder. Same reason why I wouldnt' want a screwless trailer.. Say you need to remove a piece of the skin in the back of the trailer.. (Most common spot FWIW cause people back into or clip stuff when turning) With the foam trying to remove one side of a panel and removing the bad panel would be a lot harder with the Glued in place by the foam.. The bad panel who cares cause your replacing it anyway.. But the one beside it that overlaps it would be a job since you wouldn't want to damage it..

To me my trailer is insulated very well with just the sheet foam. I cut the panels to fit tight and taped all the joints with foam tape. I also filled any gaps in tight spots with spray foam.. Considering you have metal studs that transfer heat from the skin to the wood interior the insulation between the studs only does so much. The best way would be to install sheets of insulation over the wall studs and install the interior covering over it with long enough screws to reach the studs.. This way the only major heat transfer would be from the screws. But you would loose a little space inside.

BTW I don't think spray foam is water proof. Infact its more like a sponge if the water ever gets into it

[aggie79]

BTW I don't think spray foam is water proof. Infact its more like a sponge if the water ever gets into it

Spray foam insulation is available as open cell or closed cell. The closed cell does not allow moisture to permeate.

Wlivesey (Bill) used this on his winter warrior type TTT.

http://www.tnttt.com/viewtopic.php?p=577804#p577804

[8ball_99]

BTW I don't think spray foam is water proof. Infact its more like a sponge if the water ever gets into it

Spray foam insulation is available as open cell or closed cell. The closed cell does not allow moisture to permeate.

Wlivesey (Bill) used this on his winter warrior type TTT.

http://www.tnttt.com/viewtopic.php?p=577804#p577804

Got ya didn't know they had two types. I can understand completely why the guy in the link went that route since was dealing with wood curved walls. For straight metal framed walls like what's in a cargo I'm not sure there is much advantage going with the spray in.

[GPW]

Well, it’s obviously not for everybody , but it sure did work well on Van conversions ... My Tiny CT is all Steel and will get the sprayed insulation ... But that’s just me ... Do what you think best for your trailer ...

[Engineer Guy]

Spray Foam is known to stiffen conventional Stick Built Construction by acting as a type of binder.

Note that any Reefer Truck you see has Box construction identical to to a CT and - ta da - Spray Foam Walls and Ceiling. Especially Frozen Food Trucks. Spray Foam is well wrung out in Trucks racking up hundreds of thousands of miles. It may also be used in Refrigerated Containers at Sea for shipping Beef etc.. I can't say for sure...

IMO, Wiring would have to be fixed for life, or in Chases or in Surface Mount Channels if changes are envisioned.