What is the Greenest Insulation? The Case for Mineral Wool
One of the toughest decisions in green building is the choice of insulation; every one has its own set of virtues and problems. Last summer I wrote What's The Greenest Insulation? It's Getting Harder To Decide Every Day to try and address this confusion. I didn't even mention rock wool, and have pretty much always sort of lumped it together with fiberglass.
Not so; architect Greg Lavardera claims that it is very different, and if " you think that Mineral Wool batts are similar enough to Fiberglass batts that you already know what you need to know about it, then you are a fool." So, fool that I am, I continued reading his rant, What you don't know about Mineral Wool will make you look stupid.
Greg first makes the case that batt insulation has merits that we overlook.
Lets make this absolutely clear: There is Nothing wrong with insulation in the form of batts. Batts are a convenient way to package insulation for transport, handling, and installation, which is why it is the predominant form for insulation in the US....Lets summarize the lesson here. What most green pundits blame on batt insulation is the fault of fiberglass insulation. While Mineral Wool is also a batt, it is a completely different product with many different properties. It does not suffer from any of the above problems of fiberglass, yet retains the best part - its easy to handle, easy to install, and best of all your labor force already knows how to do it. That is no small point.
Mineral Wool's rigid shape and ability to be measured and cut accurately enables it to fill stud