Still in design stage

[RJ Howell]

I have so many questions about this 'foamy' construction. Attached is a pic of my next trailer (still in design stage). I need to get the weight down and this system is intriguing to say the least!

First and foremost to me is how structural is the roof? Will it require 'stays' or just foam? I assume 1 1/2" thick.. I'm about 11'-9" long x 7'-5" wide.


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[pchast]

Welcome.....

a bunch of choices.... sheet metal forms, channel or I beam. wood in the seams. Use of both depends on the span, thickness and spacing of your roof panels. You will find several different types of adhesives used. The rounded, or teardrop, roof is improved, stiffened, by its curved form also. The skin is a large part of the foamy's strength.

Your best bet is to take some time to read and investigate what has been done.
Most of our construction approaches have been arrived at by home testing.
There are no Engineering tables nor data I'm aware of.......

[GPW]

RJ , your design looks really good , the angular semi rounded shape should be very strong … And if you don’t plan on standing on the roof you should be fine … Once you put a skin on foam , it’s no longer just foam , but composite construction … Much stronger than you’d imagine of just foam … And the old adage here is “when in doubt , make the foam THICKER …. Mine is 3.5” thick … Plus you’re welcome to add any bracing you can think of …but that just adds weight, so be careful there…

Just keep asking questions , somebody here will have the answer you need …

[RJ Howell]

Welcome.....

a bunch of choices.... sheet metal forms, channel or I beam. wood in the seams. Use of both depends on the span, thickness and spacing of your roof panels. You will find several different types of adhesives used. The rounded, or teardrop, roof is improved, stiffened, by its curved form also. The skin is a large part of the foamy's strength.

Your best bet is to take some time to read and investigate what has been done.
Most of our construction approaches have been arrived at by home testing.
There are no Engineering tables nor data I'm aware of.......

Hey, thanks for the reply! Been reading through several builds and gathering what info I can.. There's a lot of them!

[RJ Howell]

RJ , your design looks really good , the angular semi rounded shape should be very strong … And if you don’t plan on standing on the roof you should be fine … Once you put a skin on foam , it’s no longer just foam , but composite construction … Much stronger than you’d imagine of just foam … And the old adage here is “when in doubt , make the foam THICKER …. Mine is 3.5” thick … Plus you’re welcome to add any bracing you can think of …but that just adds weight, so be careful there…

Just keep asking questions , somebody here will have the answer you need …

And here I thought the 1 1/2" walls and 2" roof was thick.. 3.5"!!!! Oh My!

[RJ Howell]

My first attempt in learning this build will be a basic truck topper/camper top.


I've read joining panels with Gripper, Gorilla Glue, PL Adhesive, epoxy mix(wood flour), etc...
Can you make this a bit simpler and tell me what you like better?
I will be inserting/attaching either metal or wood to give an attachment point to the truck rail and a point for hinging the entrance flip-up.

I was heading for 1" material... Thick enough?

Edit: Further thought is to go 1 1/2" so the window design works..

[RJ Howell]

With the advise given so far, I've added a curve to the roof. I have no idea how much 1 1/2" foam will bend, yet do agree any bend will add strength. Thank you for that!



Still wondering if 1 1/2" foam is adequate?
Talking entire structure..

Also seeing quite. few folks using Gorilla Glue to join the foam panels. I've used Gorilla Glue many times on woodworking projects.
Any issues I should know about using it with foam?

I'm ready to start this build as soon as I get some confirmations that I'm heading in the right direction.
I'm apprehensive of starting only because this type of build is so new to me!