I'm getting prepared to do a simple weekend package on my 4' shortwall Featherlite, and have been reading everyone's posts, including Todd.redwrench. But I have a question. What happens if I don't insulate the walls and ceiling? I only use my trailer 3 or 4 weekends a year, always in the summer, and it will be plugged in to the arena at those times. I'm not going to put in air or furnace, I'll have to simply deal with the heat by opening the windows and screen door and for the cold I'll use an electric powered room heater.

Besides the obvious - without insulation the place will heat up or cool down quicker, will I have other problems if i don't put it in? Will I get condensation? Will the panels be at a greater risk of damage if someone leans or bumps on them? Basically I will just use my trailer as a tent, I just want a dry place to sleep and eat. But I don't want to do a poor job and regret cutting corners.

Thanks for any advice.

Besides the obvious of heat loss.  The main reason for isulation is to prevent condensation and provide noise reduction.

Even with isulation, you will have some "Dead Air Space" between the outer skin and inner wall panel. This dead air will act somewhat like insulation. But an empty cavity produces air circulation. Cold air against the outer metal skin sinks, while warmer air against the inner panel raises. This circulations contnually brings new cold air in contact with the inner paneling. Most insulation is designed to stop the air motion. So the air doesn't circulate. Hence the term Dead Air Space.  Theadvantage you have in a horse trailer. is that most of the cavity spaces are relatively small.  I mean the height between the bottom of the GN and the Roof is all of 24" to 30" and 12" 16" wide by 1" deep. This is not a large area to create convetion with in.

Bottom line,  If you want to skip the insulation, you can expect to have condensation on the interior wall panels. Not as bad as the bare metal.  And you will have heat loss/gain through the wall, that will require more heat/cooling that an insulated trailer. Meaning you need a bigger furnace/AC or need to run it longer than in an insulated trailer.

Since your use doesn't suggest you are paying for the energy consumed. ( I mean how many camp grounds charge you by the watts consumed from their Shore Power connection, most charge a flat rate fee to plug in) It's only the enviromental guilt you need to worry about. If you ever start using Propane heat or running your own generator to produce the electricity to run your A/C, then the cost reverts to your pocket book.

As PH has said, more or some insulation makes a more comfortable living environment. The largest issue I would have with no insulation, is the water vapor hitting the outside of the metal skin. Two or three people sleeping in a closed small area produce a lot of humidity. Just look at the inside of your LQ windows in the morning.

If this humidified air is allowed to touch the cool metal skin, it will condense, form water droplets and fall to the lowest point. Anyone who has thrown a mattress into an uninsulated DR, knows what that feels like.

The cost of insulating a 4' SW area is not significant. Even doing a minimal job will increase the life span of the interior furnishings and make the area more comfortable. Should you later wish to sell your trailer, it will be more valuable than one that is not insulated.

Thanks for your comments - I appreciate the advice.

Last summer I spent two weekends in the trailer with only the aluminum skin, and luckily I didn't have a problem with condensation, probably helped by it being warm and dry outside those days, plus i wasn't inside much. Here in Alberta, Canada, our summers are normally very dry, so the low outside humidity makes things dry inside in good weather. On the other hand, I have spent rainy weeks in my holiday trailer, which does have insulation, and have had things wet - moisture running down the windows and the pages in books flopping over with dampness. So I can imagine it could get really bad in an uninsulated horse trailer if the weather was damp and humid!

I priced out insulation at my local Totem Building supplies yesterday. I can buy 1/2", 1" or 1 1/2" thickness, does anyone have recommendations? Cost is $14.90 for a 2'X8' piece, at that cost I estimate it would cost me $300 to do ceilings and walls, which isn't very much when you look at the money I've got into the barebones trailer! I know my hubby and I can put in the insulation without problems, but I'm still not positive on the best and simpliest way to do the paneling later in the ceiling. Do you curve the paneling slightly - most of the paneling isn't very thick so it probably would bend, but I'm concerned on how it would look and stay - or do you simply install it straight, leaving more dead space between the curved aluminum roof and the paneling? 

Thank you all for your suggestions.

Yes, I believe the Featherlite has 1 1/2" stud walls, so it makes sense to fill it completely with the thicker insulation. I don't think the cost varies much, if at all. I haven't seen the rigid insulation with aluminum shine to both sides, but maybe I'll look a few more places before buying.

Okay, this is really a lame idea, I'm sure, but what would happen if we insulated walls and ceilings flush with the 1 1/2", taped it well, put in our stripping and wiring, and then painted the ceiling with a real textured paint? Would every piece of tape, and the stud wall show through the textured paint? (I'm guessing it would) Would the paint flake and fall off when the trailer moves? Would it bead with humidity, even if its insulated? Would it become stained and ruined quickly?

I'm not worried about paneling the walls of the trailer, that will be relatively easy because the walls are straight, the paneling is straight, and all is fine. But the ceiling - I just can't wrap my head around where to even start, and that is discouraging both me and my hubby. The ceiling has a bit of a curve, and that is going to be very tough to try to panel with basically straight panels. I've read 50 pages into this forum, and I've read everything from trying linoleum on the ceiling, to useing hullite (I have no idea if it's sold anywhere locally) to basically panelling to faux leather. And it all scares me - I'm afraid it will end up looking tacky and worse than the plain aluminum looks now!

I will be sleeping in this trailer a total of 8 to 10 nights a year. I can't feature putting $7000 to $10,000 into it, as quoted by my local professionals, for that amount of use. I also don't think my husband is interested in putting in hundreds of hours on the job ourselves, he doesn't ride so this will be my baby, so to speak. And there is no use doing anything if it looks totally cheap and tacky! I wish the "horse trailer" fairy would appear and do the ceiling for me, then my worries would be over!