Home Built SIP's

[bdub_77]

Hello there,
I'm starting the restoration (reconstruction, really) of a 1957 Corvette Travel Trailer. The entire shell is water damaged and shot. While pulling the windows out yesterday, I noticed that the walls are 1/2" ply. That's it, no framing, no insulation. I'm a long way from rebuilding the walls, but I'm giving some serious thought to SIPs. Has anyone here done that?

I've seen the skeletonized/rigid foam approach, but I'm thinking of laying out the entire side wall on the floor, with internal 1x framing for the windows/doors, and using sprayfoam in the voids, capped with the interior ply. I'm sure it will take some trial and error to figure out the correct depth to spray it so that it doesn't pop the sandwich apart as it expands, but I think I could easily build a "press" with 2x4s and some ratchet straps.

Thoughts..........Experiences..........Knowledge..........?

Brandon

[Fenlason]

I have built doors and window shutters, for my house, as SIP. I used rigid sheet foam. Actually my first ones a friend made and he vacuum bags them. He had used Dow blue board. I wanted greater insulation so we did some experiments with Polyisocyanurate. The contact between the ply and foil covered foam was stronger than the foam. [We used titebond] I have made some of my own and just stacked them and added weight.

Using spray foam and guessing how much to use to you don't blow them apart sounds iffy to me. Here when they spray foam a house. They do it with one side open, and then cut off anything that expands too much. And these are people that do it all the time.

[backstrap bandit]

Why not do it the same way as a house cut off the excess and then skin the oter side u can buy the foam used in boats with different density and weights

[Vedette]

SIP I think I just got it??
Spray Insulation Panel????????
Good Roads
Brian & Sandi

[bdub_77]

SIP = Structural Insulated Panel

They can be constructed by laminating rigid foam between sheet goods via adhesives, or by enclosing mixed liquid expanding foam. My thoughts were to do a variation on the latter, by using the off-the-shelf DIY spray foam, sandwiched between my interior 1/8" ply, and an exterior 1/4" OSB.

I should have been clearer when I said trial and error. I wouldn't be guessing, as I'd experiment on several test pieces to nail down the approach. The reason I don't want to do it the same as the spray foam contractors is that they are not focused on the "structural" part of the panel. If I followed their lead, I'd still have to adhere the last skin on which would be difficult to do uniformly, providing a monolithic unit without a shear plane. Also, the adhesive would be critical, to avoid degrading the foam.

I'm thinking of building a quick press to enclose the expanding foam thereby bonding the sheets uniformly and avoiding additional adhesives very similar to this:

http://youtu.be/_fu80LiFlOE

[Fenlason]

SIP = Structural Insulated Panel

They can be constructed by laminating rigid foam between sheet goods via adhesives, or by enclosing mixed liquid expanding foam. My thoughts were to do a variation on the latter, by using the off-the-shelf DIY spray foam, sandwiched between my interior 1/8" ply, and an exterior 1/4" OSB.

I should have been clearer when I said trial and error. I wouldn't be guessing, as I'd experiment on several test pieces to nail down the approach. The reason I don't want to do it the same as the spray foam contractors is that they are not focused on the "structural" part of the panel. If I followed their lead, I'd still have to adhere the last skin on which would be difficult to do uniformly, providing a monolithic unit without a shear plane. Also, the adhesive would be critical, to avoid degrading the foam.

I'm thinking of building a quick press to enclose the expanding foam thereby bonding the sheets uniformly and avoiding additional adhesives very similar to this:

http://youtu.be/_fu80LiFlOE

interesting.