To seal in floor insulation or not.

[Keith B]

My floor is done and I have 1.5" ridged pink insulation to put into the cavities. There will not be a "bottom skin", the insulation will be exposed. Should I silicone around the edges of the insulation/floor once in place. My gut tells me NO, that way if any water that gets between the insulation and floor can have a place to get out and air can get to it and dry... The floor is primed and painted w/ two coats of enamel. Would appreciate the voices of experience. More photos in my album.

[madjack]

Keith, your instincts are correct...you don't wanna create a water trap to rot the floor...if yu have enough paint left over to put another coat, you cut the pieces to fit, paint the bottom and stick 'em into the paint...a couple of screws and fender washer and the would be ther for good(or a really long time) (whichever came first)........
madjack

[Keith B]

Excellent. Thank you Madjack. I really don't have enough paint left, however, the pieces fit good and tight and also, the trailer frame stringers will run perpindicular every 2', so the insulation really can't fall out. I could drop a couple quarter sized dabs of silicone to use as a "glue" though.

[mikeschn]

You know it... don't cause a water trap.

Screw the insulation up into the floor, and call it a day. Some fender washers might help your screws from pulling through the EPS.

Having the insulation up against the floor will create a convection barrier that will help keep your teardrop warm. You need not worry about a tiny crack along the edges...

Mike...

[halfdome, Danny]

Keith there is always another opinion and here's mine:
Contrary to popular belief I sealed off my floor & insulation.
I stapled & glued 1/8" Baltic Birch, filled the staple holes & sealed it with the black goop. My floor underside is 16 1/2" from the pavement and it's still just as clean as it was the day I built it and I live in Washington where it rains a lot. People put wood on the outside of boats so I don't see what the problem is sealing the floor. I didn't want to find my insulation blowing off somewhere down the road.
Just my 2 cents worth. Danny

[Juneaudave]

I hate...hate...hate...this question and thread!!!!! I also sealed the bottom...and went one step further to use epoxy and paint instead of black goo for sealing it. Certainly not the cheapest and lightweight way to go....overbuild....yes.... is epoxy and paint more durable that black goo with rocks hitting it....who knows...piece of mind...????? That's why I hate this question.

I guess I'm not worried about trapping water...shucks...it's wet up here all the time. I figure if water can't get in...whats to rot? Ultimately, I put the ply on the bottom because the 1 inch pine stringers had more flex with the spacing of the frame members than I liked. The bottom ply definately stiffens things up.

[Keith B]

Excellent... thanks for all the tips guys... should have the walls stood shortly , then it's time for well....building the roof spars. I really appreciate it everyone.

Hey Danny.. I thought about doing that too, BUT... my TD is getting "fat" and so now I'm taking every precaution to build lighter without sacrificing stength. My floor is 2x w/ 15/32 ply and seems to be more than adequate even off the trailer and the support given by the trailer frame stringers.

Juneaudave.. I hear ya... I've debated and debated and debated about this thing... but, this is what I ended up with, so it's going to HAVE to work. I chose the enamel paint for the simple fact my house trim has enamel, get's blown with wind, rain, hail, snow and ice and it hasn't been repainted for 11 years and still looks perfect...the black goo just wasn't a good option for me due to winter and the shop heat and fumes... just wasn't worth the risk...and at 28 degrees outside that wasn't an option either.

The further along I get the more fun it is... but I am REALLY worried about the rear hatch, getting it to fit and making it water tight.. you can BET I'll be on this forum a lot at that time. Got Steve's CD from the shop contest, and his way is great, however, I'm already "past the point of no return" to use his method.. success will be had regardless, I'm confident.. but not cocky at this point

[halfdome, Danny]

Keith, I hear you on getting fat, mine is a heavyweight to be sure but I have no complaints. I did a search and found several travel trailer mfrs have been sealing the underbelly for at least from the 60's. Here is one for example. Danny
The floor of a TrailManor uses the same rigid, double skin sandwich panel construction, except the foam core is 3" thick with plywood under the top aluminum skin to absorb surface impact loads. The 3" floor is much stronger and better insulated than the particleboard or plywood floors used in other trailers, and it feels great on cold mornings.

[donkro]

I don't understand why people put the insulation under the ply floor. It seems very vulnerable there. Wouldn't it be OK to use treated ply for the floor, seal it with black goop, then frame the top of the floor with 3/4 EPS and put a 1/4 inch ply on top of that?

[Arne]

My plan is to put 3/8 on floor, 1/8 on the bottom... insul in between.. then cover the bottom with roofing tar... simplifies all these questions, and I wind up with insul protected, a very strong floor, and a flat bottom... the best of all worlds.

[SteveH]

The way I did it, and would do it again if I built another, is the floor is 3/4" ply with roofing goop on the bottom, period. It may help in the frigid North to have insulation in the floor, but I seriously doubt that more insulation than 5" of foam rubber is needed, or can be measurably improved on.

The original teardrops that I have seen used 1/2" plywood.

[Keith B]

From what I've seen, it's a mixed bag of who does or who doesn't use insulation in the floor. In Kansas, we have over 100 degrees in temp flex.. in the winter it can be -10 and in the summer it can be 110, so anything you can do helps. I agree, I think the 1/2" floor is PLENTY. I thought about going heavier, but thanks to the advise of this forum I went w/ 1/2"... right now the walls are stood and the whole thing is setting on 4 stringers 33" apart and it's MORE than solid enough. As far as the insulation being vulerable under the trailer... sure it is... but it also has to beat through 1.5" of it before it can ever contact ANY wood.. and when it does.. well, I'll replace it.. insulation is cheap; but I don't expect it to get the daylights beat out of it. Sure the occassional rock or something will fly up in there, but I think it will be more than fine and a lot less weight. None-the-less, I'm pretty happy with how it turned out.

[Ira]

I don't understand why people put the insulation under the ply floor. It seems very vulnerable there.

It's just the easiest, lightest way to build. All I did was use the black goop, and stuck on the insulation with a few fenbder washers.

What can happen to it? A rock's gonna hit it?

And Ken, I just looked at your album.

COOL!!!

You going solid walls, right?

[Keith B]

My walls are 1/2" ply w/ 1/2" framing and insulation then 1/8" birch door skin. Right now the thing seems very solid and with only 1 bulkhead in. Walls are secured with F26 waterproof construction adhesive and screws every 6"

[Ira]

My walls are 1/2" ply w/ 1/2" framing and insulation then 1/8" birch door skin. Right now the thing seems very solid and with only 1 bulkhead in. Walls are secured with F26 waterproof construction adhesive and screws every 6"

(Sorry, called you Ken above.)

Oh! Now I get it--it's already framed! I was confused by what I thought was a route-out for a wire, because from a photo in your album, it looked like a solid wall.

VERY nice!!!

Now that I see that wire in the back coming out from the framing (right wall), I see that it's already framed.