I did my attic 2 winters ago, mainly to reduce the attic temp due to the AC blower unit is up in the attic, so during 90+ days, instead of the AC is on all the time and takes forever to cool the 2nd floor, it is on less and cool down the 2nd floor a bit quicker. I will probably need to replace the AC with a bigger unit soon. I got this stuff on ebay for around $150 shipped, it probably dropped my attic summer temp by 20-40degrees.