Weight VS cost VS easy of build questions

[rustytoolss]

OK I'm new here, and have construction questions.
First off, I would like to build a Standy TTT not a TD, on a 6x8 popup frame, and would like to keep the weight at, or under 1000lbs. (nothing fancy, just basic camper, no AC, fridge,water systems)some cabinets,bed etc. like I said basic shelter. I've built a lot of things with wood/plywood. So I understand that type of construction.
My questions are,
1 From the stand point of basic build cost (walls,floor,roof, etc)/ is there much if any difference in overall material cost ? How much differce ballpark ?
2 From the stand point of ease of construction (since I know wood) which would be easier (wood/plywood) or foam ?
3 From the stand point of weight (foam or wood/plywood) ballpark difference of weight savings of foam over wood.
This would be my first build. I know a guy that built a 5x8 TD. He is trying to sell it, because he wished he had built a standy. Trying to learn from him. And not wanting to make the same mistakes.
All input very welcome. Thanks

[KCStudly]

To me the difference between wood and foam is more a question of aesthetics, color, texture and durability.

A hybrid like my TPCE build is going to weigh a lot more than a similar "pure" foamie, but that difference comes with a warm cozy feeling wood paneled interior and a certain fit and finish that would be very difficult to achieve with fabric and paint.

IMO, to reach your weight goal, you will have to stay more on the pure foamie path with less wood. Consider that a 6x8 PU trailer frame will probably weigh in around 400 lbs give or take with axle, hitch hardware and all of that, and you will want to allow for camping "stuff" like a cooler full of ice and food, cookware, camp chairs, etc., that doesn't leave a lot left over for heavy wood.

Some ways that I saved weight on wood parts was to use clear select cedar for most of my framing. It is surprisingly light compared to other options and is also naturally rot resistant; though it is rather costly, there is virtually no waste because there are zero knots.

Also, by doing a built up floor with 5mm skins top and bottom, I get 1-1/2 inches of insulation for about the same weight as 3/4 inch ply, but, by my estimation, it is stiffer. Not more puncture resistant, but enough that I can kneel and scoot around without crushing.

No outer wooden skin saves weight. Light weight open shelves or cabinets with face frames but no doors (maybe fabric curtain "doors" or bungee netting instead) can still add a lot of structural "unit" strength without adding a lot of weight. Like GPW said, foam arches stiffened with glue and fabric can replace wood.

It's not about the strength or weight of any single piece, it's about how all of the light weight pieces join together and contribute to the overall strength.

Bottom line, avoid typical framing size lumber and thick plywood.

[S. Heisley]

Hi again, Rusty:

Since you know wood, that might be the easiest; but, think about that Northern Ohio snow and rain. If your plywood isn't sealed really well, bad problems can develop. Plus, you'll need to be diligent in its care, especially if it is stored outside.

If you look here, you'll see that weight for any build is greatly dependent upon the builder:

viewtopic.php?f=21&t=60392

I'm guessing that a foamie would be the least expensive; but, everything is, again, relative to the builder and what he/she puts into it.

There are so many ways to build these little units that a definitive answer is nearly impossible.

Knowing you are trying to keep the weight at 1,000 pounds and you want to build a 6x8' standy, you're going to have to be very careful, possibly weighing every piece of wood you use. I still say that a foamie is your best bet. Take a look at CPowell's Buella...: viewtopic.php?f=55&t=63179 He's been doing a good job at keeping the weight down on his standy.

[KCStudly]

The Big Pink is another good example of a foamie standy that came in at a very reasonable weight, IIRC it was under 1300 lbs(?).

[S. Heisley]

Another idea, if you decide to build a pop top, is to make the bottom out of plywood and the pop-up pieces out of foam covered in canvas or fiberglass. Remember also that you don't need to stand on top of your bed; so, you don't need the roof to be very tall there. That could save some weight.

[pchast]

Over the years I've done my share of hobby woodworking and shed construction.

As far as materials. I found virtually no difference in cutting and assembling, foam vs wood.
That said, using foam required me to change some thinking. There the complete assembly
was important to provide strength and support. Think airplanes not houses is a little more
involved than it sounds.

I could have been more careful and reduced the wood used. I might have cut 60 to 70 lbs off
my build. Note: I did use cedar for all but the hard points needed for door hinges and lock set.

[GPW]

Everything you want to know , and more ... viewtopic.php?f=55&t=39373

[TheOtherSean]

OMG, you just gave a link to The Big Thread. It'll be days, maybe years, before any poor soul is likely to finish it. It should be renamed "Abandon All Hope, Ye Who Enter" it is so long and likely to induce despair.

[GPW]

Sean , the information is there for all to read .... It’s like the old saying , you can lead a Sean to water , but you can’t make him read the Big thread ...

Should we just repeat ourselves over and over for the benefit of every new builder that comes along ... or just provide a simple ( but lengthy) repository of knowledge , readily available to all ...

[ScottE]

Your build requirements are very similar to what I started with and my weight turned out to be less than 900 lbs.
viewtopic.php?f=55&t=64860
I highly recommend the canvas over foam method and I've been very happy with the end result from all angles. I don't know what your base frame weighs but I bet you can create a fine foamy with it!

[rustytoolss]

OMG, you just gave a link to The Big Thread. It'll be days, maybe years, before any poor soul is likely to finish it. It should be renamed "Abandon All Hope, Ye Who Enter" it is so long and likely to induce despair.

Sorry to have started a post that will create problems. But being on a tight budget, and trying to keep weight low. Add to that , first time builder. I have to admit that I'm the type of guy that over thinks everything-everything. So I'm sure others have asked questions, that the answers have all ready be covered. I'm sure that we are not trying to start website wars. Just looking for a path to make the best choices.
Like I said at the top of my post . I am new here. Looking to the members of tntt for guidance, that's all.

[rustytoolss]

Your build requirements are very similar to what I started with and my weight turned out to be less than 900 lbs.
viewtopic.php?f=55&t=64860
I highly recommend the canvas over foam method and I've been very happy with the end result from all angles. I don't know what your base frame weighs but I bet you can create a fine foamy with it!

That looks a lot like what I have in mind, thanks.

[rustytoolss]

[quote="ScottE"]Your build requirements are very similar to what I started with and my weight turned out to be less than 900 lbs.
viewtopic.php?f=55&t=64860
I highly recommend the canvas over foam method and I've been very happy with the end result from all angles. I don't know what your base frame weighs but I bet you can create a fine foamy with it! [/quote
Looking over your build. What is your overall size of the plywood decking with the overhangs ? Any idea how much your bare trailer weighed ?, What are you towing with a 4cyl or 6cyl Subaru?,, How does it handle towing at say 60 mph ? Really like what I'm seeing.

[GPW]

Rusty , think of a Foamie as a thick foam box covered by a strong skin ... A box you can shape and decorate any way you want ... Foam is easy to cut and sand , no special tools needed ... normal carpentry procedures apply , using gluing for the main attachment method ... ( we find a sharp handsaw cuts through thick foam sheets like “butter” , and is a gratifying way of doing the cutting and less messy too ... )
Since you like to think things out , consider this .... A simple Harbor Freight is around 250 pounds (supposedly) ... a 2” X 4’ X 8’ sheet of extruded styrofoam is ~ 10 pounds ( 2 lb/ cu.ft. ) , canvas has listed weights , depending how thick a canvas you use ... everything you put into a trailer can be closely calculated as to weight ... everything save glue and paint which use a solvent that evaporates... leaving a lighter “dry” product.
Plywood as we know is HEAVY ( ~ 57# / cu.ft. ) , and unfortunately , anything we can afford to put in a trailer ( we are “THRIFTY” !!! ) will need some type of intense waterproofing to survive more than a couple of seasons. We tried OSB flooring (even heavier) but it was easier to waterproof by slobbering “the Mix” all over it in several coats ... cheaper too , by half ... ( The FS has an OSB floor , and we’re two years and still Good ... better after I finish all my lower drip edging ... )
Since you understand construction , just think of this as a Waterproof (rot proof) box , using as little wood as possible for the main stressed areas , door frames, hatches, etc. Everything else is pretty much the same except the materials are THICKER.. So where someone might use a 3/4” plywood side , we use a 2” thick side or more (Twice as thick is 8 times stronger) ... I used 3.5” thick beaded foam on my 6’X13.5’ FoamStream , a standy’ , OSB floor on a homemade trailer ( not the lightest) and plywood ribs inside and we calculated the weight to be around 800 pounds empty ... It tows super despite being larger than a TD ... extra braking is not necessary ... and being light it doesn’t “bounce’ over road bumps ( low mass = less acceleration)

I always like to see Foamie trailers as the “Thinking man’s (or woman’s ) trailer ... The more you think about it before hand , the better it works out in the final result ... A process you can see develop from infancy in the “Big Thread” ... it all started with a simple idea of waterproofing wood .... and lots of Thinking !!!

[daveesl77]

Conch Fritter is a hybrid with probably a bit more on the wood side of things. However, if I can ever convince "the one who must be obeyed" to let me build a second one, I really, really want to try my hand at a foamie that has only a minor amount of wood. I can see the advantages in foam when properly done. It can be very strong, you can make almost any shape you wish, no worries on rot or rust and the weight savings is an absolute.

With all that said, most folks believe the main problem in towing is the weight. It is a concern, but the primary problem is the profile. A curved/angled front/rear is far more aerodynamic than a flat surface. A 1,500# trailer with curves both front and rear will tow better, with less power needed, than a square one. Just a function of physics.

dave