Working In Attic With Blown In Insulation . Most of it contains up to over 50%. See install batt and roll insulation for details.; Blown Fiberglass Insulation Gary E. Spotts Insulation Inc. Telford from www.spottsinsulation.com Do not disturb the insulation. A trusted hvac professional can explain. Insulation falling through the attic access into your living space is not a good thing for the family, your pets or for guests.