which building material is the best insulator?

Answer 1

I assume you are asking insulation for a house ? , OK if tit is , a house structure will increase it's insulation by the thickens of the exterior walls , and the thickness of the ceiling insulation , first on the exterior walls , The out side cladding Bricks will be a better insulation than stucco or siding , now if you do a log house it's insulation properties are very high , on your frame house having a thicker wall that starts from 2x4 to 2x12 the air space combine with a thicker battens of fiberglass insulation of higher "R "rating of course increases your insulation , the same goes for your ceilings , and you can further insulate the basement floor by laying 2" 3" Styrofoam sheets under the concrete slab before is poured in . You have to be care-full with your vapor barriers , you can wrap a house so tight that the air inside becomes stale and you can develop more problems than if you let the house breath ,
Now in the warm climates of the south ,a house build of cinder blocks and stucco on the out side , can maintain a cooler effect in the inside so in a way it also acts as an insulator of heat .

Answer 2

I saw a show on TV comparing standard pink fiberglass to newspaper, hay, foam, etc. The hay performed very well! The problem with it is that if it gets wet (plumbing leak or water damage when putting out a fire) it has to be completely replaced, whereas the fiberglass can simply dry out.

Answer 3

insulation

Answer 4

have you try styrofoam ? :)