Under carriages

[kenafp]

Okay.
For the bottom panel of your TD, the one that faces the ground and sits on top of frame, I have several questions:
1. Has anyone used exterior grade paneling for that exposed piece?
2. In coating the underside, have you also coated the end grains with the same coating, or used something different for aesthetic purposes?
3. How does the coating hold up with the exterior grade (usually pre-treated) plywood?
4. I have to biscuit join three pieces of paneling to get to my 5x10 floor measurement. How well does exterior grade paneling work with this type of joinery?
5. I am thinking of going with regular plywood (since exterior grade is usually warped). Coating just the one side with roof tar, and the edges with an epoxy or varnish to seal them.

Thoughts?

[kenafp]

Am planning on using 1/2 inch pw ( as opposed to 3/4), 1" spacers to add insulation to the floor, and topping it with a 1/2 inch layer. I am also toying with making it wider/taller (using 2x4s instead of 1xs) to give me some additional storage under the mattress. Not sure though.

[citylights]

For the bottom panel of your TD, the one that faces the ground and sits on top of frame, I have several questions:

1. Has anyone used exterior grade paneling for that exposed piece?

Yes, I have seen that.

2. In coating the underside, have you also coated the end grains with the same coating, or used something different for aesthetic purposes?

Best recommended practice is to treat all exposed ends with polyurethane cut 50% so it soaks in good. See rot doctor... http://www.rotdoctor.com

Second best and the classic method for underside and ends is to use a roofing tar- emulsion. Third, black beauty fence post preservative and paint, or truck bed liner. Most have the teardrop sidewalls cover the floor end pieces.

End pieces can also be painted with Titebond II glue as a sealant. Tight bond II glue has very good water resistance characteristics, even better than titebond III.

3. How does the coating hold up with the exterior grade (usually pre-treated) plywood?

The key is to seal it against water. Pick your method and go for it. The better the seal, the longer lasting the teardrop... 5 years, 10, 20, 50...

4. I have to biscuit join three pieces of paneling to get to my 5x10 floor measurement. How well does exterior grade paneling work with this type of joinery?

I biscut joined mine. 1/2 inch deep biscuit cuts, 1 inch wide by 1/4 inch thick biscuit, Titebond II glued and clamped overnight. Solid, especially after glued and screwed to the lower frame.

5. I am thinking of going with regular plywood (since exterior grade is usually warped). Coating just the one side with roof tar, and the edges with an epoxy or varnish to seal them.

Perfect, long lasting, quality products.

[citylights]

Am planning on using 1/2 inch pw ( as opposed to 3/4), 1" spacers to add insulation to the floor, and topping it with a 1/2 inch layer. I am also toying with making it wider/taller (using 2x4s instead of 1xs) to give me some additional storage under the mattress. Not sure though.

Most do not insulate the floor for 3 season camping. Remember the teardrop floor also gets a foam bed, which is also insulation.

For winter camping, most just insulate the spaces under the floor between the trailer framing with glue in 1/2, 3/4, or 1 inch foam pieces. The ones that go all out for insulation build a sandwich floor, 1/4 inch thick skin, 1/2 inch foam with 1/2 inch thick framing at the edges, 1/4 inch thick skin.

2x4 framing is way overkill, is very heavy, and is not recommended. You need to think in terms of 1x2 framing members. Glue and clamp or glue and screw space frame (torsion box) and sandwich construction is really very strong and light weight. Think light framing members and thin skin like an airplane... Not 2x4s like a Tank!

If you want storage under the mattress, try a box built in underneath into the space between the trailer frame members with a hatch (that is what I did) or a little more common, a drawer on slides accessed from the outside usually at the teardrop door.

Here is my teardrop in progress picture as example of what NOT to do. My teardrop is about 2000 lb when it should only be about 1200 lb. Anyway mine is 2x4 frame at the bottom over the trailer frame and 3/4 plywood floor. Totally strong and heavy and stupid. I should have read this site and studied the design concepts more before I started.

I still love my teardrop, but it just can never be towed by a small car. Small truck, SUV, or bugger vehicle towing only.

[48Rob]

5. I am thinking of going with regular plywood (since exterior grade is usually warped). Coating just the one side with roof tar, and the edges with an epoxy or varnish to seal them.

That is your best bet.

Treated plywood is not good for your health, and the treatment stops bugs, but will not stop checking, cracking, and rot (at least not the common consumer grade).

As long as you make it/keep it waterproof, whatever product you use will be fine.

You can build with cardboard, but it HAS to be waterproof.

Rob

[alaska teardrop]

Thoughts? Yes.
Attach a .050" or .063" sheet of aluminum to the topside of trailer frame. Build walls. Lay a full sheet of 1", 1-1/2" or 2" extruded polystyrene insulation on top of the aluminum. Lay a thin lightweight flooring on top of the insulation.


Underside protected. Waterproof. Total floor insulation with no thermal bridges. Significant weight savings. Will not absorb moister & rot. Simplicity of construction.
IMO, most mattresses have very little true insulation value & will absorb interior moisture when laid on a cold floor, especially open cell foam.
Fred