Where to buy dow thermax insulation

Without getting into an argument about insulation, could someone help me with buying DuPont/Dow Thermax polyiso sheathing? In particular, I'm looking for it in a 1" thickness. I live in northern New Mexico.

I have scoured the internet. The popular insulation site, Insulation4US, has Thermax listed in various thicknesses. However, when I placed an order, they responded that they are currently unable to procure Thermax.

I have asked Lowe's and Home Depot about making a special order.

I have asked local building suppliers about making a special order.

All of these have been a dead end. Does anyone else have an idea? Perhaps there's a source that I have overlooked.

Thanks!

Four years ago it was in stock at home depot, Half inch Polyiso, Foil on both sides. I bought a bunch of it there.
Looks like it is still in stock.

Four years ago it was in stock at home depot, Half inch Polyiso, Foil on both sides. I bought a bunch of it there.
Looks like it is still in stock.

Thanks for the feedback, Michael. I'll keep that in mind if I'm unable to find Thermax.

I went down that same rabbit hole during my research with it two months ago and could not source thermax white anywhere I looked (and I looked everywhere, same as you, custom home depot, home builder sites that would sell 3,000 sheets minimum, etc). Gave up. But while testing a few different types of insulation in the garage, I did buy a few of lowe's 1/2" r-matte poly-iso sheets and stacked them together on the floor. Was horrified to find the layer between the two soaking wet with condensation one morning when I lifted the top 1/2" sheet off. Guess the dew point was reached between the sheets. Dried them, cleaned them, researched more, realized it wasn't the right solution for me. Returned. Got XPS. All tests remained dry as a bone. Easy to work with and shape, just like cutting styrofoam.

Good luck!

Was horrified to find the layer between the two soaking wet with condensation one morning when I lifted the top 1/2" sheet off. Guess the dew point was reached between the sheets. Dried them, cleaned them, researched more, realized it wasn't the right solution for me. Returned. Got XPS. All tests remained dry as a bone. Easy to work with and shape, just like cutting styrofoam.

Good luck!

Mark

Thanks, Mark for sharing your experiences.

...
I did buy a few of lowe's 1/2" r-matte poly-iso sheets...

Thanks for the feedback, Mark. I really appreciate it. Is that a typo? I assume you meant Rmax.

The Rmax I bought is Polystyrene, Pink in color. Good for insulation against cold.
I used both Polyiso and Rmax for an all weather camper.
A inch and a half total in the walls ,Floor and Ceiling.

Thanks for the feedback, Mark. I really appreciate it. Is that a typo? I assume you meant Rmax.

R-max is the brand, R-Matte is the type. It was the only polyiso (PIR) I could find within 100 miles, whereas every local store had tons of XPS and EPS, presumably because they sell a lot more of it after the low temp blowing agent freezing news made polyiso less appealing. It was odd stuff even though it was brand new. Yellow looking brittle interior that was prone to breaking. One side was painted white to stop the foil layer on that side from condensing but the white paint rubs off if it gets wet and you try to clean it. I wasn't impressed at all, even though I like the better performance it offers in the summer.

Cheers.

R-max is the brand, R-Matte is the type. It was the only polyiso (PIR) I could find within 100 miles, whereas every local store had tons of XPS and EPS, presumably because they sell a lot more of it after the low temp blowing agent freezing news made polyiso less appealing. It was odd stuff even though it was brand new. Yellow looking brittle interior that was prone to breaking. One side was painted white to stop the foil layer on that side from condensing but the white paint rubs off if it gets wet and you try to clean it. I wasn't impressed at all, even though I like the better performance it offers in the summer.

Cheers.

Thanks for clearing that up. Sorry for my misunderstanding.

If you can not find what you are looking for then you might consider closed cell foam. Better "R" value than Thinsulate and probably better than Thermax for noise reduction. I found it being used to insulate brewing tanks and piping. Might be available locally if you have breweries in the area. Insulation was easy to install and will work on curve surfaces.

Aerocel® AC Sheet & Roll - Aeroflex USA

If you can not find what you are looking for then you might consider closed cell foam. Better "R" value than Thinsulate and probably better than Thermax for noise reduction. I found it being used to insulate brewing tanks and piping. Might be available locally if you have breweries in the area. Insulation was easy to install and will work on curve surfaces.

Aerocel® AC Sheet & Roll - Aeroflex USA

Thanks, Dave! I had looked at Aerocel a while back. At a 1" thickness, it's R-value is 4.1 compared to 6.5 for Thermax polyiso. I have thought about using it between the corrugations in the floor, but I haven't been able to find its compressive strength. I am currently planning to use 6-lb/ft^3 Mincel (XLPE) there instead, which has a compressive strength of 25 psi at 25% compression. Thermax is also 25 psi.

Thanks, Dave! I had looked at Aerocel a while back. At a 1" thickness, it's R-value is 4.1 compared to 6.5 for Thermax polyiso. I have thought about using it between the corrugations in the floor, but I haven't been able to find its compressive strength. I am currently planning to use 6-lb/ft^3 Mincel (XLPE) there instead, which has a compressive strength of 25 psi at 25% compression. Thermax is also 25 psi.

I used polyiso where the surfaces were flat and used the Aerocel on the curved surfaces and in the cubby holes above and below the window indents. Used polyiso where I could for the higher "R" value and much less cost. Polyiso much more difficult to install than the Aerocel. I glued all the pieces of polyiso together with spray foam in the joints. Two layers of Aerocel with second layer covering the seams of the first layer. Aerocel easy to install like Thinsulate but with higher "R" value. Did not compare Thinsulate cost vs Aerocel but did eliminate the shipping cost by buying Aerocel locally.

Between the floor corrugations I used 1/2" closed cell foam. Difference in height from top of corrugation to low is about 7/16" so 1/2" foam is slightly compressed. MLV on top of the foam/corrugations and then 1/2" plywood on top of the MLV. No issue compressing the foam. Not sure the MLV has much value for noise but it did allow me to seal the floor to prevent water getting to the steel.

This week I discarded the thin indoor/outdoor that covered the gym mat and extrusions. There were 3 pieces of carpet. The edges would turn up at the seams. Replaced the indoor/outdoor carpet with one piece of heavy commercial carpet. New carpet stops in back at the first leg of the table. No need for carpet under the bed platform. Can easily remove the single piece of carpet for cleaning.