Using Fleece scraps for Insulation
 

Recently I found an ad on Craigslist for free fleece scraps for insulation. The ad says: This is new material, completely clean, from our sewing production. The fleece is inherently flame resistant. We manufacture clothing to protect people from fire so the fleece will not burn, perfect for insulation.

I didn't know that fleece was flame resistant and/or if it would be good for this kind of thing.

I recently found access on the ceiling for the first floor joists and can see from one end to the other. My thought was to pack the space with the free fleece scraps to help sound insulate.

Any objections or advice?

Fire resistance, moisture handling, and insulation value are some of the most important factors with insulation. Generally cotton absorbs moisture and doesn't diffuse it back out. For fire resistance, I'd test it myself with a propane torch or something similar.

The main bad thing about synthetic fleece is it tends to be acrylic.
Acrylic fiber burns like crazy.

Some fleece materials used for certain clothing items are treated with flame retardants. As MN renovator suggests, the real way to see what you've potentially got a source of is to pick some up and test it with a torch in your fire pit outside. If it is not treated, I expect it burns about as quickly as a cotton ball. If it is treated, I expect the flame stops spreading when you take the flame source away.

It's been a while since I posted this, yesterday I noticed the ad for free insulation again and stopped by to talk to the shop. I brought a couple of bags home and put a torch to different pieces. They didn't burn at all, but did melt a minute amount.

I have access to the floor/ceiling joists between the first and second floor in my house. The plan is to cut down on the noise from the first floor by filling the cavity with this material. It is about 10" tall.

Before I put some between the floor joists in my house, any objections? Would I dense pack this?

Someone else put it in their ceiling for insulation.
http://ecorenovator.org/forum/attach...1&d=1486832975

I found this on Wikipedia:
It is hydrophobic, holding less than 1% of its weight in water. It retains much of its insulating powers even when wet. It is machine washable and dries quickly. It is a good alternative to wool (of particular importance to those who are allergic or sensitive to wool). It can also be made out of recycled PET bottles, or even recycled fleece. Despite its fuzzy appearance and feel, it is not flammable, but instead melts when exposed to flame.

Regular polar fleece is not windproof[6] and does not absorb moisture (although this is often seen as a benefit, per above).[7][8][9] Fleece readily generates static electricity, which causes the accumulation of lint, dust, and pet hair. It is also susceptible to damage from high temperature washing, tumble drying or ironing. Lower-quality polar fleece material is also prone to pilling.

Looks like it would work as insulation, at least as well as pillow stuffing. It's hard to beat free and recycled. As long as you don't have rodent problems, that is. I'm sure they would consider this an upgrade from fiberglass or stonewool to move into.