Fiberglass offers an r value of 2 2 to 2 7 per inch while rock wool has an r value of 3 0 to 3 3 per inch making it a slightly better insulator than fiberglass according to the u s.
Insulation attic fiberglass vs rockwool.
Select your attic insulation application.
One you will need to choose the material fiberglass mineral wool cotton or sheep s wool.
This makes rockwool a little better at insulating than fiberglass.
Mineral stone wool insulation batts are slightly better insulators than the off the shelf fiberglass batts sold at most lumberyards and home centers.
Fiberglass has an r value of between 2 2 to 2 7 compared to mineral wool weighing in at 3 0 to 3 3.
Mineral wool insulation for the same wall runs about 1 to 1 10 per square foot.
Use rockwool thermal stone wool insulation to insulate the attic of a new build extension or to increase the r value and top up the current attic insulation especially in an older home.
Fiberglass insulation costs 25 to 50 percent less than mineral wool.
It is also better at absorbing low frequency range noise than comparable fiberglass.
Made from stone rockwool can withstand temperatures up to 2150 f.
R value is a big deal in insulation so lets see how they stack up.
Fiberglass insulation for a 2 6 wall costs between 57 cents and 72 cents per square foot.
Mineral wool batts for 2 4 walls have an r value of 15 while a standard fiberglass batt made to fit in a 2 4 wall has an r value of 11 or 13.
This helps to delay the spread of fire in a situation where every second counts.
I recommend using roxul in acoustic panels and traps and use the fiberglass in wall and ceiling cavities where it is fully closed in.
Fiberglass insulation typically contains 20 to 30 percent recycled content.
Fiberglass has an r value of 2 2 2 7 per inch while rockwool has an index of 3 0 3 3 per inch.
The boiling point of a more common fiberglass insulation can average between 1 000 1 300ºf 537 7 704 4ºc.
General use of rockwool and fiberglass.
And two you will have to decide whether to use batts or rolls.
So that means for standard 2 4 wall mineral wool comes in r 15 batts while fiberglass comes in r 11 or r 13.
However fiberglass does not have the same fire resistance as rockwool and melts at 1 000 degrees fahrenheit.
Batts are pieces of blanket insulation that are pre cut to manageable sizes 15 24 inches wide by 48 or 93 inches long while rolls are strips of insulation similar to batts in width.
Whereas rockwool fibers are spun from liquid rock fiberglass is spun from liquid glass and glued together with a resin.