Which Rockwool product for my walls?

[Bystickel]

I read through numerous debates on what to use for wall insulation. I want to use Rockwool mineral wool, but can't seem to find anything that seems suited.

People mention Rockwool, but don't seem to specify which product I need something very close to 1.5" to fit within my 1960's walls. I have no clue how compressible Rockwool is.

Does anyone know what product that's flexible and comes closest to fitting?

If this doesn't work out, it's pink insulation for me.

[gator.bigfoot]

You might want to try the comfort board. The batt is too thick and most likely won't work. The board would work for most places except in the end caps. There you'd have to get creative in how you cut it so it fits.

[Bystickel]

Thanks for the suggestion. I was concerned that anything with 'board' in the name would be too rigid, though I'm only doing the lower sections, so there's less curve to deal with.

I think I saw someone mention cutting the 3.5" down to 1.75, filet-style. I'd be curious to hear what kind of knife one would use for that.

[gator.bigfoot]

Originally Posted by Bystickel

Thanks for the suggestion. I was concerned that anything with 'board' in the name would be too rigid, though I'm only doing the lower sections, so there's less curve to deal with.

I think I saw someone mention cutting the 3.5" down to 1.75, filet-style. I'd be curious to hear what kind of knife one would use for that.

Just search "insulation knife". The usual places carry them. Some bread knifes will also work as will the standard utility knives. I have a variety of them and each one has a particular advantage of the other in certain situations and insulation types.

I personally would not cut down the 3.5" batt insulation. Especially Rockwool products. The board is thinner to begin with. You could also use something like the https://www.amvicsystem.com/products...oard-graphite/ series. These boards bend to some degree.

[A W Warn]

Originally Posted by Bystickel

I read through numerous debates on what to use for wall insulation. I want to use Rockwool mineral wool, but can't seem to find anything that seems suited.

People mention Rockwool, but don't seem to specify which product I need something very close to 1.5" to fit within my 1960's walls. I have no clue how compressible Rockwool is.

Does anyone know what product that's flexible and comes closest to fitting?

If this doesn't work out, it's pink insulation for me.

GTS Interior Supply in Missoula should have the 1.5" mineral wool in stock. I think they carry the John Manville brand.
My local Home Depot has 1.5" RockWool in stock, but most HD stores don't keep it.
Any specialty supplier that caters to commercial drywall contractors should have "sound attenuation and fire safeing insulation". That's what most people call 1.5" mineral wool in my area.

I've have used this material a lot in commercial construction for sound attenuation and fire safing. It is flexible enough to bend around the curves in your trailer walls. However, holding it in place in those curves, prior to installing the interior skins, might be a challenge.

It has an R-Value of about R-3 per inch, so it will only give you ~4.5 total thermal resistance rating.

[fullahotair]

I just installed Rockwool in my trailer. I bought the Comfort Batt R15 and like others posted previously simply cut them in half using the insulation knife at home depot/lowes. It was surprisingly quite easy to do. I was a bit skepticle at first. I would do it again in a heart beat. 4 bags for a 70' Overlander.

Nate

[Bystickel]

You folks are great. Thank you very much. I feel much better about the whole thing.

[Can of beans]

To buy it Rockwool in the right thickness, you need to look for Rockwool AFB (acoustic Fire Barrier). As sound barrier they sell it in 1/2" increments. I used 2" and it compressed just right into the cavity. I also bought EPDM foam tape for the ribs, but that was only 1/16" thick. Someone else on the forum had a link to Insulation4us.com that was the best place to buy it. I think I got it in under 2 days. It took 5 bags of 2' wide batts to do my 31' trailer, I bought 6 bags because there is free shipping after a certain dollar amount that made it a wash almost to buy 6 bags vs 5 and pay shipping.

It hasn't been terribly cold the few times we've camped in it so far, but it seems like it works pretty well, the trailer warms up fast when I want it to, and cools off fine with the air conditioner. I used 3M70 spray adhesive to hold the batts in place for the upper curves and ceiling. Wear a mask and safety glasses.

[gator.bigfoot]

You can buy rockwool comfortboard in various thicknesses.
https://www.rockwool.com/products/co...ications&Sizes

[03enduro]

I used 1.5” rocksul board. By making cuts on the back side of it you can make it conform to the curve. I even used it in the rear area (below the dome) and was very happy with the fit and how it stayed in place.