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Joining Wall to Floor....Yet Another Dumb Question!

Posted:
Sun Nov 14, 2004 10:56 am
by SteveH
I've done a search and looked thru all the older threads and have not come up with an answer for my question, so here goes.
Assuming 3/4" plywood side walls and 3/4" floor, what is the best way to join the two together?
I'm considering using a 2X2 under the floor, screwed and glued to both the floor and wall. Thought about putting the 2X2 on top of the floor, but don't like that because it would be on the inside of the trailer under the bed. The problem I see with it under the floor is that the frame needs to be inside the 2X2. Is this a problem? As far as size is concerned, it's not a problem for me as I'm going to build the frame also.
Please let me know your thoughts, and please quit laughing!

Posted:
Sun Nov 14, 2004 11:06 am
by BrianB
What about securing the wall to the frame? You'll need to let you wall hang down to cover the frame (which is what I'm doing), but it'd be sturdy that way.

Posted:
Sun Nov 14, 2004 11:14 am
by Ken
Take a look at photos 29 and 38, they are not close ups but might give you an idea. I glued 1x2s standing up to the sides, glued and used 3” deck screws through the 1x2’s, 1x4’s and then through the ¾ inch plywood floor.
http://pg.photos.yahoo.com/ph/t1pt0n/al ... /my_photos

Posted:
Sun Nov 14, 2004 1:47 pm
by Frank
Steve,
Try looking at the way Larry did on his outback. By far not the only way, but a tried and proven to hold up way.
http:www.outbackteardrop.com/ is the address, hope this helps.
Frank

Posted:
Sun Nov 14, 2004 2:45 pm
by Woody
You can always use 1 1/2 to 2 inch aluminun angle to attach the side wall to the floor. It would also solve the trim detail at the seam where they join and it could be painted

Posted:
Sun Nov 14, 2004 2:51 pm
by SteveH
Brian,
Yes, thought about that alsom but the way I see that is the frame becomes part of the "box" construction rather than the box residing on top of the frame. Don't know if that is a good idea, or not.
Ken,
Seems like you have done something simular to what I didn't want to do, put the wood block on the inside of the trailer.
Frank,
Yes, I'd seen the way Larry did his, and I'm shure it is strong, but don't care for the 1 1/2" extra height of the 2X4.
Woody,
Is the aluminum angle on the inside on top of the floor, or on the outside under the floor?
Thank you all for your inputs.
Re: Joining Wall to Floor....Yet Another Dumb Question!

Posted:
Sun Nov 14, 2004 7:55 pm
by bdosborn
SteveH wrote:I've done a search and looked thru all the older threads and have not come up with an answer for my question, so here goes.
Assuming 3/4" plywood side walls and 3/4" floor, what is the best way to join the two together?
I was looking for a picture of the same thing when it came time to attach my sides, but I never found one.
Here's what I ended up with:
The sides are sitting on the trailer frame. The deck just keeps the sides from moving. After reading a post from Grant, I didn't want the sides to hang off the deck with the glue and screws in shear. I'll let you know how it works in a couple of years.
Bruce
P.S. I took this picture right after I attached the sides so the temporary bracing of the wall is showing to the right.
Re: Joining Wall to Floor....Yet Another Dumb Question!

Posted:
Sun Nov 14, 2004 8:22 pm
by BrianB
bdosborn wrote:After reading a post from Grant, I didn't want the sides to hang off the deck with the glue and screws in shear.
Could you give more details on what he was talking about?

Posted:
Sun Nov 14, 2004 11:54 pm
by bdosborn
Yup, I saved it:
Re: attaching sides to floor?
Large Type Version of this Page
Author: Grant Whipp
Posted: 7/21/2003; 12:58:52 PM
Topic: attaching sides to floor?
Msg #: 10289 (in response to 10198)
Prev/Next: 10288/10290
Reads: 171
O.K., George - I'm back!
There's nothing wrong with either Larry's or Roly's method, and a bunch of us already know what a terrific job they both have done on their trailers! However, I have a personal aversion to attaching side-walls in a shear-load fashion, i.e.: glued & screwed to either the end/side of the floor or to a block and then onto the floor and/or chassis (still a shear-load on the block, but better than glue & screws into the floor-end alone). So, here's how I do it (in kind of a nutshell):
• First off, I build my chassis 1-1/2" narrower than the intended width of the body.
• Secondly, I figure the thickness of my floor and intended width/depth of the "skirt" and subtract that from the overall height of the body, often laying out the entire profile on the sidewall plywood and cutting that portion off the bottom after the profile has been cut out. Then I attach the galley/cabin cabinetry to the sidewalls (when they're ready) and set that entire assembly onto the floor and glue & screw through the floor into the sidewalls and cabinet bulkhead, thereby creating a compression-load joint (all downward force is placed directly onto the floor & frame and is not trying to rip apart a shear-type joint)(also, I actually roll the sidewall/cabinetry/body onto it's back and glue & screw the floor DOWN onto the walls & bulkhead).
• The next step is to then attach the "skirts" by pre-drilling and gluing & screwing them into the bottom of the floor. Depending on the material thickness chosen for your sidewalls, you can often use the part you cut off the bottom of your profile as the actual "skirt", but it's often easier to just make new ones out of 1x4 stock.
That's kind of an abridged and simplified version of the process, and it's really rather simple to do. I don't by any means think it's the best or only to do it, but it's the "Li'l Bear Way", and it's been holding up to the "daily grind" for 19 years, now. I'll put it all down in detail in the near future (and I know I've been saying THAT for a while now!), but hopefully that will give you something more to think about and consider.
However you do it, it really does sound like a great project! I have no doubts that it will turn out just fine, and with all the help that is offered on this 'Board, how could it otherwise?!?!?
Good Luck, and as always ...
CHEERS!
Grant

Posted:
Sun Nov 14, 2004 11:56 pm
by bdosborn
Here's another post on the same topic:
Re: Will This Work?
Large Type Version of this Page
Author: Grant Whipp
Posted: 11/26/2003; 10:47:59 AM
Topic: Will This Work?
Msg #: 14384 (in response to 14360)
Prev/Next: 14383/14385
Reads: 159
O.K., Steve ...
... I think I see where you want to go ... ;-} ;-}
First of all, let me say that it's no real big secret around here (at least, to those who've put up with me all this time!) that I am NOT a big fan of shear-loading screws trying to hold side-walls to floor or side-walls to chassis, even if acccompanied by copious amounts of adhesive - I've just seen too many failures of those kinds of joints in my 35+ years of working in-and-around the RV industry. Nor am I a huge fan of insulating the floor of a teardrop (and all the effort and expense that goes with it) or "tinning" the bottom to seal it. And while some very finely crafted, attractive, and functional teardrops HAVE been built this way, neither am I in agreement of placing the walls flush with the sides of the chassis - with the exception of the '56/'61 Mechanix Illustrated Camp Trailer, NO vintage teardrop plan nor comercially-built vintage teardrop was built in this manner (admittedly, it's an asthetic thing, but you CAN'T tell me that asthetics DON'T play a role in the appeal of teardrops, then or now!).
That said, may I suggest that you dado the inside wall 3/8" deep where the floor meets the wall (slipping the floor into the wall by 3/8"), thereby allowing at least SOME amount of compression support at that joint (as you have it drawn)? Also, if you increase the size of your bottom nailer to 1"x1", you can glue-and-screw IT to the inside of the 3/4" wall, thereby providing an even stronger joint. Depending on your final construction technique, you might even decide to drive mounting screws through the nailer into the chassis before you add the paneling (but to me, that just seems to be even more un-necessary effort!). However you decide to build it, Good Luck, and we'll be eager to follow along and see the final result!
While I'm here and geared up, please allow me to opine on a couple of things as they relate to teardrop construction. To me, teardrops are the K.I.S.S. principal exemplified as it applies to the CAMPING TRAILER genre. Keeping the construction as simple and straight-forward as possible while building in a desired amount of strength and durability is the foundation of a good design. The asthetics come in the shape and the details. IF one of your project goals is to make the trailer an exercise in construction technique and craftsmanship that is largely hidden by paneling and outer skin, then that is definately a good thing and an admirable goal. If, however, your primary goal is to get out and simply go camping in a cool little trailer, to enjoy the benefits and added social elements of teardropping, then wouldn't it make sense to keep the construction as simple as possible?
Re: floor insulation - Why, really? If you're building on a framed floor and you simply want to fill the void between frame members, then O.K. ... but why otherwise? I've been in my teardrop in 18" of snow on the side of Mt. Shasta (Nor-Cal), the walls had 3/4" insulation, the roof 1", and the floor had 4" cushions on top of 3/4" plywood (NO floor insulation, otherwise), and while we entered the cabin with 4 layers of clothes on, we were down to our underwear within 15 minutes and experienced NO heat loss through the cushions. We used to do this regularly, and even experienced much colder conditions - I'm certin that the addition of an extra 1" to 1-1/2" of insulation to the bottom would not have made a measurable difference. but, that's just OUR experience ... ;-} ;-}
Re: "tinning" or sealing the bottom of the floor with a layer of metal - with the availability of asphalt-emulsion-based sealants and bedliner material (both spray-on and now brush-on "Hippo-Liner"), why go to the extra effort? Unless the metal (aluminum or steel) is glued directly to the wood, you'll be creating a "moisture trap" between the wood and metal (and the inside of that metal WILL sweat!). That wood needs to breath, and trapping moisture between metal and wood at the bottom of your trailer is actually PROMOTING wood rot!
Remember K.I.S.S. - Keep It Simple & Satisfying. Just my opinion ...
Above all, enjoy the process of building your own teardrop, but especially the end result - the USE of that teardrop and the joys that THAT will bring!
CHEERS!
Grant

Posted:
Mon Nov 15, 2004 12:38 am
by SteveH
Grant,
First let me thank you for you input and digging up the past posts that I overlooked. I DO appreciate it.
I fully understand the problem of shear loading the joint between the wall and the floor, and that is why I opened the thread, wondering how to do it without first, consuming interior space with a reinforcement block, or second, setting the wall on top of the frame. The later being a cosmetic effect that I'm trying to avoid. Additionally, I'd like to avoid using a 2 X frame under the flooring because of the added height.
It all revolves around a "look" that I have etched in my mind of a teardrop trailer that my Dad owned when I was in highschool. That trailer was just too cool, I always thought, and I believe after spending some time looking at old family photos and some old info posted on the verious sites I have explored, was a Deanette built right here in San Antonio in the 50's. Anyway, the trailer's frame was not visible from the side view and that effect is what I'm trying to achieve, only in wood as I believe the Deanette was a mostly metal frame trailer.
Your idea of a dado between the floor and wall is something that had crossed my mind but only briefly as I don't believe I would be capable of making such a cut on a 4 X 8' sheet of plywood with any accuracy.
At this time, the design I like the most is this:
http://www.angib.pwp.blueyonder.co.uk/t ... ubnewl.pdf
This drawing shows the detail of the wall to floor joint and chassis design I was considering. I understand the whole design is aimed at light weight for "European" use. Then I ask myself, why is European use any LIGHTER than American use? I understand the Europeans typically drive smaller less powerful cars than we do, but would having a light weight trailer be in any way a bad thing? Assuming, of course, it's not so light weight as to self distruct in normal use.
I guess at this point I might be overanalizing this a little. I remember a time that having spent as much time as I have thinking about this, I would have had it half built already!


Posted:
Mon Nov 15, 2004 5:13 am
by Woody
Inside or out , It is a preference thing. It all depends on the overall look you are going for.

Posted:
Mon Nov 15, 2004 8:44 am
by BrianB
How about this. If you want to cover the frame like I do, weld on a lip the same width as the thickness of your plywood onto the bottom of the frame. Do it so that it supports the edge of the plywood so that you can screw the plywood into both the frame AND floor without the shear loading issues.


Posted:
Mon Nov 15, 2004 9:09 am
by SteveH
Brian,
Excellent idea! I like that. Should be the best of both worlds as the frame is supporting all the weight, the floor to wall joint is just for the structual integrety of the "box", and there is NO reinforcement piece inside the trailer.
Only thing even potentially bad that I can see is that it creates a place for water to accumulate and possibly soak into the plywood wall.

Posted:
Mon Nov 15, 2004 11:24 am
by shil
I built my floors of 5/8" T&G exterior flooring, screwed right to the trailer frame.
I cut the floor to leave a 3/8" overhang over the edge of the frame.
I then ploughed a 5/8" dado, 3/8" deep, into the sidewall, just high enough so that the overhang hides the frame.
The sidewall's attached to the floor with construction adhesive. It just 'snaps' onto the 'lip' of the floor. A screw every foot or so holds it in place until the glue sets up.
It ends up a lot like BrianB's diagram, with the floor intending into the wall, and no lip on the bottom.
Dados are the greatest. Everything gets lined up on the workbench; once it's cut it's good to go. You've never got to line up two pencil lines and hold things in place while you drive in a drywall screw with your third arm.
Shil