Teardrops n Tiny Travel Trailers

Just brainstorming here. Thinking of a superlight popup roof. Aluminum could work if bolted together, but, looking at a 30 degree angle in the design made me rethink how I could bolt it together. Welding alum is not an option in my basement...

What about some thick PVC pipe? I looked at a few pages of posts here and haven't seen anyone do it. You can get 4-way and 3-way connections, 90, 45 and 30 degree joints... And leaving the hinged end unglued with a simple strap could allow it to hinge. Pipe is easy to cut and drill into, and could be used to run wiring, or even as gutter drains.

The actually roofing, that the pipe would hold up, will be ultralight. Sandwiched foam, between the pipes with a skin on top and bottom which extends out over the pipes with a 1/8" wood for the inside, and either thin wood or aluminum skin on the outside. The sandwich would also hopefully strengthen the pipe structure. The roof will have a roof vent with fan, and possibly a small stargazer window, possibly a solar panel. It would be 6-feet wide with a center support.

Here's what I'm thinking:

So in the above pic, it's an angled view. The green corners would be the "hinged" edge. The blue square would be where the roof vent goes.

Thoughts anyone?

pics for a visual

I know of at least 1 build on here that uses PVC pipe as a frame, I believe it is in the foamies section. I am sure there are others.

I can't find any examples on here of people who have done it. Can someone provide links?

http://www.tnttt.com/viewtopic.php?f=50&t=62852&hilit=pvc+PIPE#p1122773

If you are going to laminate wood/foam/wood anyway you don't need the PVC framing, maybe just a solid wood perimeter that you can attach hinges and latches to.

Pmullen503 wrote:http://www.tnttt.com/viewtopic.php?f=50&t=62852&hilit=pvc+PIPE#p1122773

If you are going to laminate wood/foam/wood anyway you don't need the PVC framing, maybe just a solid wood perimeter that you can attach hinges and latches to.

Because it'll be a long piece if I go that route. I didn't measure it, but maybe 10-12' total in length. So it's gotta be as light as possible, but still strong.

I'm saying the PVC pipe frame will not add to the stiffness or save weight. A continuous layer of foam laminated between two skins will be stiffer, stronger and lighter than a PVC pipe/foam laminate.

But what about the 30 degree angle halfway down that length? Just angle the framing and use pocket screws or? Two frames fastened together at angled joint?

What I would do is make slots in the foam core so I could glue vertical plywood ribs every foot or so. 1/4" plywood would be good enough. Making sure they were accurately cut so they would be glued to the top and bottom skins. They wouldn't need to be too long, maybe extending a foot on either side of the joint. I'd make the perimeter frame of solid wood since that would be a little more resistant to water and delamination. If I would only be using fasteners in the face of the plywood (not into the edges) you could also use a good marine plywood.

A bigger problem I see with this concept is sealing it. You would need a robust system of seals and gutters to keep water out and even then you'd have water sitting in the joint for long periods of time due to surface tension. Think of driving at 70 mph in a rainstorm and you'll get an idea of the problems. Perhaps a better solution if you want a hinged top is to make it a box that comes down over the sides. That would make it more rigid but it would weigh more. But that would help with the issue of wind driven rain.

Thanks for the insight! The idea of the ribs is a great one! The joint was one concern for me as well, and keeping water out. I wondered if a hurricane hinge would work in this case, or just go for a long piano hinge. Either way, it would need to be covered with a rubber seal to keep the water out. Although I'm not sure if a hurricane hinge would need a seal or if it would be good enough to withstand driving in the rain.

Hurricane hinges work when the water is coming from one direction (either gravity or wind driven). If you plan to put it on the front then covering it with a rubber seal makes sense. The air flow is turbulent between the TV and the trailer so the water could be moving it any direction.

I have a front hatch on mine with a "live" hinge (continuous strip of heavy plastic) on the roof but the front sill is angled down 15 degrees with rubber seals. I towed once for 6 hrs. in heavy rain and it stayed mostly dry in the front compartment but a few drops of water still made it through. BTW, any horizontal gap of less than about a 1/4" will hold water due to surface tension. I ended up cutting off the bottom of my side door to make the gap 3/8" and angled the sill 5 degrees to drain the water effectively.

A simple solution for me might just be to make the tent fabric go all the way around, even a short strip behind the hinge. Then a full rubber gasket seal all the way around just outside of the tent fabric. And just have some drainage notches here and there so water doesn't sit anywhere.

Camp4Life wrote:But what about the 30 degree angle halfway down that length? Just angle the framing and use pocket screws or? Two frames fastened together at angled joint?

Gussets! you would need to work them into your design somewhere as they do take up space. but if you were to put a large gusset on each side, extending down over the fabric, it would provide enormous strength for very little material.

yrock87 wrote:

Camp4Life wrote:But what about the 30 degree angle halfway down that length? Just angle the framing and use pocket screws or? Two frames fastened together at angled joint?

Gussets! you would need to work them into your design somewhere as they do take up space. but if you were to put a large gusset on each side, extending down over the fabric, it would provide enormous strength for very little material.

I thought of that also, but then I would have to make the outer frame stick out over the walls so that the gussets don't prevent the roof from laying flat on the walls. Either that or cut out grooves in the walls where the gussets would slide into when the roof is lowered.

Here's a pic of what I mean:


So a gusset(in red), would prevent that corner from laying down on the corner of the wall (indicated by the green arrow).

Too many options and variables!

Yeah, it would either need to be on the inside of the outside of the wall. But it wouldn't need to be big to make a large difference, 6 inches of depth at the corner, tampering out two feet each side would make a world of difference. You could either replace it directly onto the side of the build, with a 1/4 standoff so it clears your wall. Or you could place it inside your seal. Heck, if you made it inside and also built intermediate ones in the middle of the trailer maybe you just make a false ceiling at that area. You may not miss the little bit of headspace in that 'corner' of the ceiling. The other option was mentioned previously. Add walls to your roof. That eliminates the need for your accordion style expanding seal, and allows you to build in large gussets into the walls. You could built them at a minimal weight with foam construction and a few key wood members.

Either way you go, I appreciate your style and am enjoying your approach.

yrock87 wrote:Yeah, it would either need to be on the inside of the outside of the wall. But it wouldn't need to be big to make a large difference, 6 inches of depth at the corner, tampering out two feet each side would make a world of difference. You could either replace it directly onto the side of the build, with a 1/4 standoff so it clears your wall. Or you could place it inside your seal. Heck, if you made it inside and also built intermediate ones in the middle of the trailer maybe you just make a false ceiling at that area. You may not miss the little bit of headspace in that 'corner' of the ceiling. The other option was mentioned previously. Add walls to your roof. That eliminates the need for your accordion style expanding seal, and allows you to build in large gussets into the walls. You could built them at a minimal weight with foam construction and a few key wood members.

Either way you go, I appreciate your style and am enjoying your approach.

Thanks for the input, and the compliment! Decisions are hard to make and get changed often. The drafting/planning/designing part is easy enough, and I want to be detailed enough to know what I'm doing when the building starts. Time will tell how the actual building will go