A properly insulated attic reduces energy costs by reducing the flow of air into and out of the top of a house. Well-insulated houses stay warmer in winter and require less output from heating systems. Blown insulation is well-suited to insulating attics, with their sloping roofs and hard-to-reach spaces. Blown insulation achieves different R-values (the ability to resist heat flow) by varying the thickness of the layer; thicker layers have higher R-values. And most manufacturers provide recommended R-values based on geographic region; colder regions require more insulation and higher R-values. Installing blown installation isn't difficult.
Things You'll Need
- Tape measure
- Insulation blower
- Flashing tubes
Make a walkway the length of the attic by laying 2-by-12s end to end across the ceiling joists. Place flashing tubes near any recessed light fixtures and heat-generating features, such as chimney flues and exhaust fans.
Block off any recessed light fixtures with metal flashing; leave at least 3 inches between the fixture and flashing. Install flashing around any heat-generating feature, again leaving at least 3 inches.
Measure the attic with a tape measure and multiply the attic's length by its width to determine square footage. Use the square footage to determine the amount of cellulose (insulation) needed.
Pour insulation into the blower. Have a helper keep the machine full to keep the insulation flow smooth and even. Climb into the attic and go to the far end; blow from the far end back to avoid contact with the insulation.
Hold the hose parallel and close to the floor with insulation falling 10 to 12 inches away. Blow right and left. Avoid blowing insulation in fixture blockers.
Measure the thickness depth with the tape measure. Add insulation as necessary.
Tips & Warnings
- Blow insulation early in the day; attics get hotter as the day progresses.
- Wear goggles, mask, gloves and protective clothing; insulation is an irritant.
- Photo Credit roof image by sanyal from Fotolia.com
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