Subfloors?

[squatch]

Newb here with my 1st question. I've been lurking a while and have noticed that most teardrops including Foamies (my interest) have framed out sub floors. Is this to allow the use of thinner lighter weight plywood or to keep the ply floor from warping? It just seems that on a ultra light Foamie build on 3/4" ply the framing underneath could be done without. Especially if a light 1x2 frame on top was used to attach the foam walls to. I would think the trailer frame would be rigid enough for the plywood floor. Please enlighten me.

[GPW]

Mine is just 3/4" plywood flooring , no framing ... planning on bolting it up to the trailer as is... If you build larger than the standard 4'X 8' floor then you'd need some additional framing ... whether inside or out ... Did that help ?

[eaglesdare]

i don't have a subfloor either. my ply is bolted right down on the frame.

[eaglesdare]

oh and welcome to the forums. if you get a chance check out the tearjerkers site also. sister site to this one. link is at the top of this page.
you are in the md area? that group of tearjerkers are the chesapeake bay chapter. very active with gatherings. all are welcome regardless of whether or not you have a teardrop or a tent or just sleep in the car.
come on over and check them out.

again welcome!

[pat g]

Squatch,

My intention was stiff but light. Thus the framed, screwed and glued sub floor. 3/8 ply both sides glued and screwed to 2x2 framing. Probably weighs close to GPW's 3/4 floor. Maybe a bit heavier but not much. For me, the sub floor seemed a good choice, but hey, there is no right way!

Pat G

[squatch]

Thanks for the info. I've been reading a lot here. There is just so much to digest. Some of the sub floors were evident. Such as those that are wider than the trailer frame to surround the wheel wells.

I'm still very much in the thinking and planning stages of a foamie. I'm thinking of using a 3/4' ply sub floor with a 1"x3" or 1"x4" on edge all the way around on top of the plywood. The 1x3 would be glued and screwed from underneath through the plywood into the 1x3. Inset just enough to allow the 2" foam walls on edge just outside of that. Flush with the plywood edge. This way the walls could be secured with either dowels through the foam and 1x3 or screws from outside in as well as glue. Once the whole outside was skinned and painted then add a piece of 2" or 2.5" aluminum angle all the way around the outside edge. This would be attached to the ply from underneath. This would sandwich the Foam wall between the aluminum angle and the 1x3. It should be like framing the sub-floor but on top and also the aluminum edge would protect the lower edge of the foam walls from knocks.

I'm also thinking of maybe doing some version of a big DADO joint where the foam walls meet each other. Maybe 6" or 12" for each lap. Then drill and insert glued dowels in each direction. This should be much stronger than just a butt joint but would probably require a bit more foam board. Stronger on rough roads. I'm thinking of just building a simple sleep only, no galley 4x8 foamie with a traditional shape on a small boat trailer I have. It would be a little tricky to make the joints. But not too bad. Foam is so easy to work with a Surfoam plane.

[GPW]

We just used the standard ply , not the lighter stuff, and boy was it HEAVY !!! UGH!!! (had to get help to move it ) Only reason to use a sub floor + framing is if you're building a TD bigger than the usual 4X8... But it's all about how YOU want to build it ... We know the "minimum" works , so anything else added would only make it stronger...
SQ , what you propose sounds Very Strong ... You know what to do !!!

BTW, I bought a hand full of 1/2" dowels to "pin my floor" as Cone' s Dad suggested .. Makes sense !!! Everything helps .... so many good ideas to choose from ...

[Conedodger]

Once the whole outside was skinned and painted then add a piece of 2" or 2.5" aluminum angle all the way around the outside edge.

I see a problem with anything on the outside as water coming down the outside (Rain) would then have a route between the aluminium and the foam to the floor where it would sit. The glues we use dont seem to mind a lot of water but just like plywood they dont want to be left damp as it just penetrates and will rot. Its far better to let it run off.

Water that runs down and that seeps up, will dry but if there is somewhere it can puddle it will soak in and stay wet.

Far better to just have the cloth / TB2 over this area on the outside, folding it under so there is no where for water to get in at all. If you feel it needs more strength use another strip of cloth and TB2 as GPW does. You will be amazed how strong it gets.

Your idea of a "1"x3" or 1"x4" on edge all the way around on top of the plywood" would work great idea as it would act as a large key as well as give more area for the foam / wood glue to join. It would certainly stop all shear in the wall to floor joint.

From everything I can see and understand about this Foam stuff, it has very little strength when you stress it in a small area, so you have to spread the load over larger areas. Foam gets its extra strength from having a covering stuck to it which makes the stress spread over a large area.

I have now found another supplier for foam covered panels in the UK and they supply the product to RV manufactures.

For interest http://www.coldsaverpanels.co.uk/panel-systems.htm

Basically its the foam covering that give it strength, this can be almost anything and certainly cloth / TB2 has been proven to work, people just need to be convinced

[GPW]

Cone, great find !!! Sure would be nice to try some of those "industrial" panels ... vacuum bonded and all .. that just HAS to be Strong eh ? Wonder how dear they are???

[squatch]

Conedodger, I have thought about the water intrusion thing. If I did this I would caulk inside the aluminum angle with a polyurethane caulk such as Sika-flex or log builder. This stuff is amazing. My log home has it all over between the logs ect. The bond id so strong you would rip the wood apart trying to seperate logs after it has cured. My home roof is a stress skin panel. 6" of foam sandwiched between 1x6 tongue and groove and OSB bonded to the styrofoam on top. Tha caulk hasn't seemed to be a problem with this. I would test 1st of course.
http://www.twincreeksloghomes.com/detail.aspx?ID=42

This is the trailer I intend to build on.


It's a bit flexible so I'm looking at a very rigid Teardrop to stiffen it up a bit. I would like to protect the bottom edge as I'll probably add some slightly larger diameter tires and wheels. This will be used for basecamping in national forests on 4x4 trips. I won't be pulling it far off road. But it will see gravel roads and short stretches of rough roads where I probably shouldn't even have a trailer like this. LOL
Just have to go slow. This very road will likely be a maiden voyage.


The trailer has seen worse with canoes on it. That's why I'm thinking Foamie. Very light rigid structure. Should work well with some beefing in the right places. The aluminum on the bottom edge might save the day if I brush a rock. I'm not planning on using the teardrop for long distance overlanding. Just a mile or so into the nice camping spots with my group. The narrow 4x8 should be a big plus as well as the wheels outside the box.

[Conedodger]

I think Sikaflex will eat the foam so test first, however i still feel it would be strong enough without it and without it there is no problems to seal.

Cant wait to see your build, a tiny trailor with tiny wheels would look great. Maybe you can design it to the scale of the wheels that way you will look like a giant in all the photos.

Best of luck

[GPW]

SQ, Nice looking trailer (and Canoe ) ..!!!! Just bolting the floor to the trailer should make the whole thing a lot stiffer... or you can add some more steel ...
I think the aluminum would be OK as an edge protector , but you should consider what Cone said about water ... How about mounting the Aluminum on little standoffs (washers) so the water passes between the wall and the protector ... That or caulk the heck out of it ... but as we learned with RVs , caulk only lasts so long and must be inspected/ maintained ... Something we're personally trying to avoid...

Time for a rant ... I still can't imagine why the RV industry insists on using caulk to seal their trailers... other than it's the cheapest thing they can get ,quick to apply , and a recurring revenue source for their dealers , who suggest it be inspected often and re-caulked once a year ... a very expensive proposition if you have them do it ... Just doesn't make sense ... Just another part of their philosophy of using the cheapest materials , cranking them out as fast as they can , and letting the owners worry about it later... (and Pay handsomely for it too)

Since discovering Big Mike's method of using only the Best materials for trailer construction , I look upon the whole RV industry with much disdain and contempt !!! GRRRRRRRRR!!!!!!!!!!

[squatch]

I'll test 1st for sure. The poly caulks have a 30+ year lifespan. The stuff on my house has been exposed to the weather for 18 years now and is still like new. The aluminum wouldn't go on till the shell is completed and painted. That alone should help with the water thing. Maybe just do the exposed front corners. Skid plate sorta. The stand offs aren't a bad idea.

The 8' shell should only extend onto the tongue about 2' and will be U bolted to that. It's 6' from the tip of the V to the rear. The trailer currently has a very long tongue on it to accomidate my 17" tandem canoe. 12' solo in the pic. I also have the shorter factory tongue that came on the trailer. That should probably be perfect for a teardrop.

I intend to wrap the entire shell in canvas including the floor. Inside and out. I did some searching and 10oz canvas in 60" widths seems pretty common and reasonably priced on the web.

Thinking 1 door on passenger side with a window in it. Matching window or maybe even a larger one on the drivers side. Both must open for ventilation. And a 14x14 roof vent with maybe a fan in it. Windows will depend on what I can scrape up at local junkyards. Several have old campers and rv's. I like salvage stuff. The theme for this is simple, cheap, strong, recycled, use what is on hand. I don't intend to buy much more than foam, glue, canvas, maybe the plywood.

I have some work around the old homestead that has to be accomplished before I get started on this. So other than planning and maybe parts collecting I doubt much will be accomplished within the next month at least.

[GPW]

SQ, take your time and gather your parts ... more time allows you to search for better deals ... Enjoy the "scavenger hunt" ... just another Fun part of building Thrifty Foamies
QUOTE: "I like salvage stuff. The theme for this is simple, cheap, strong, recycled, use what is on hand. I don't intend to buy much ..."

Your Theme is Our Theme !!!!

[squatch]

Thanks, I'm no stranger to that theme. The truck above I completely rebuilt from the ground up over 15 months. Same for my bass boat, My garden tractor. It's kinda dumb to buy new and change everything. I prefer older better made stuff that is cheap and I can build as I go to better suit my purposes. I guess it's a long term side effect of growing up poor. I prefer to think of it as an advantage. The treasure hunt as I like to call it is a big part of the enjoyment for me. I've met some great folks in the process over the years. Anyone can buy new stuff from the same mold. My experience is much of it is junk anyways. I tend to seek out the unique and fun. Makes life more interesting. Keeps me out of more serious trouble as well. Teardrops fit the bill. Let's face it. Normal folks don't head out to the woods in cold weather then cram themselves into a shoebox to sleep. Good they're boring!