3/4" Insulation Unavailable - What Now?

[mahai217]

So, I decided to build my TD with 1/4" skin, 3/4" skeleton and insulation, and 1/8" or 1/4" interior skin. I purchased Steve Frederick's Shop Manual and working through it and have even bought some of the lumber. I've tried sourcing the insulation but can not find any within 100 miles -- maybe more.

Any ideas? What about getting 1 1/2" and slicing it in half (thickness -- from 1 1/2" to two sheets of 3/4")? Any ideas on how to do this?

I live in the Boise, Idaho area.

Thanks again!

John

[lrrowe]

This may be a silly question, but what about building with the 1 1/2 insulation. Thicker walls would mean better insulation and noise damping.

[tony.latham]

So, I decided to build my TD with 1/4" skin, 3/4" skeleton and insulation, and 1/8" or 1/4" interior skin. I purchased Steve Frederick's Shop Manual and working through it and have even bought some of the lumber. I've tried sourcing the insulation but can not find any within 100 miles -- maybe more.

Any ideas? What about getting 1 1/2" and slicing it in half (thickness -- from 1 1/2" to two sheets of 3/4")? Any ideas on how to do this?

I live in the Boise, Idaho area.

Thanks again!

John

Arghhhhhhhh....

Iv'e been there a couple of times. On my first search for 3/4" foamboard, there wasn't any here in Salmon and nothing in the Bitterroot Valley. We had a trip planned to Spokane and I found the 3/4" pink stuff in a Home Depot. On my third 'drop, I found it in a Home Depot in Missoula––they had it in beadboard with a foam backing.

Which leads me to the second teardrop I built, a little 4 x 8 for my sister. The skeleton was made from 1/2" AC plywood. Finding 1/2" pink board was easy.

Soooo... you might consider going that route.



A skeleton made from 1/2" AC (I'd avoid the void-rich CDX) is fine for the skeleton wall with 1/4" sheathing. The other thought is purchasing 1" pinkboard and taking it down a quarter with a random orbital and 80 grit sandpaper after it's glued into your wall's holes. It won't take long. Just keep your vacuum nearby. 3/4" pinkboard is thicker than 3/4" plywood so you have to take this step anyway....

The only problem I had with my sis's walls were that the shelf the ceiling fits on is narrow. With a 3/4" skeleton, I can snap it down with my 1/4" crown stapler over a bead of glue. I was afraid to do that with the 1/2" skeleton––afraid it would split out. I ended up laying a bead of PL Premium down and nailing it down with skinny little nails. Works fine.

Tony

[greygoos]

They sell 3/4 polystyrene insulation at Home Depot on Federal Way. They are 18 inches wide and 4 feet long. 6 to a pack. Somewhere around 10.00

[Redneck Packrat]

3/4 is pretty common here, all the mom&pop type places stock that but not the thicker stuff. I'm building with 2" and am having the same problem finding enough of it in decent enough condition to use.

[martymcfly]

BMC has it. I paid for it there on Franklin and picked it up out by Broadway. It was $23 a 4x8 sheet r-tech with foil on both sides.

[Kevin A]

If all else fails, use 1/2" foam with a 1/4" or 6mm ply to fill the void.

[mahai217]

This may be a silly question, but what about building with the 1 1/2 insulation. Thicker walls would mean better insulation and noise damping.

Not a silly question. I'm just planning to build so I fill the voids of the skeleton with insulation. If I used 1 1/2" insulation I would have to use 1 1/2" skeleton.

[mahai217]

BMC has it. I paid for it there on Franklin and picked it up out by Broadway. It was $23 a 4x8 sheet r-tech with foil on both sides.

Thanks Marty! I will stop by!

[mahai217]

Thanks for all of the ideas folks! You gave me a few things to think about. I appreciate you taking the time to share your knowledge and experience.

John

[elcam84]

Wow 3/4 is all the borgs here carry. Sometimes they have 1" but anything thicker is special order and very expensive. Unfortunately no Menards here.

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[pchast]

John,

Have yo looked at foamys at all...
If you glue that 1.5 in. foam to the skins you will
only need some blocks to screw things too in the foam.
The skeleton would be unnecessary.

[mahai217]

John,

Have yo looked at foamys at all...
If you glue that 1.5 in. foam to the skins you will
only need some blocks to screw things too in the foam.
The skeleton would be unnecessary.

[elcam84]

Well dont forget how sailboats are made. They are just foam with fiberglass on both sides... Why not do the same with a teardrop and eliminate the frame and use plywood instead of fiberglass. Even something like a heavy laminate on one side would add allot of strength but everything has to be glued well.

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[QueticoBill]

Well dont forget how sailboats are made. They are just foam with fiberglass on both sides... Why not do the same with a teardrop and eliminate the frame and use plywood instead of fiberglass. Even something like a heavy laminate on one side would add allot of strength but everything has to be glued well.

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True. And why not just use fibreglass? It does depend on the adhesive.