Home improvement shows make it look easy, but installing insulation yourself can be messy, tiring and, if you don't plan carefully, as expensive as hiring a professional.
As you plan your insulation project, keep in mind that it's also important to use vapor barriers and ventilation to maintain a healthy balance of air and moisture movement throughout your home.
The number one rule is to follow the manufacturer's instructions exactly. Skipping steps and taking shortcuts could mean significant reductions in R-value - and a waste of your money and effort. Allow yourself plenty of time and make sure you have enough materials to complete the job.
You can do it yourself if:
- You've identified the type and amount of insulation you currently have.
- You can purchase the additional insulation from a reputable retailer with a knowledgeable staff.
- You've successfully tackled other home improvement projects.
- The area is accessible and easy to maneuver in, and has few obstructions.
- No structural changes are involved.
- The existing insulation is dry and properly installed.
- Your roof is in good shape.
- You're including vapor barriers and ventilation in your plans.
A few more tips to keep in mind
- DO invest in "no-itch" products - they're much easier to handle and safer to work with.
- DO wear goggles, a dust mask or respirator, gloves, long sleeves and long pants when working with insulation. For the best protection, wear a hat, tuck your sleeves into your gloves, and tuck your pant legs into your socks.
- DO be very careful moving around in your attic. Watch out for overhead rafters, and walk only on ceiling joists. If you have room, lay a plywood panel across the ceiling joists to walk or kneel on.
- DO install batts and blankets at right angles to the first layer.
- DON'T disturb existing insulation - especially loose-fill. Moving it around can create gaps where air can leak through.
- DON'T put insulation over recessed light fixtures, ceiling fans or ventilation fans. If you're using loose-fill insulation, use sheet metal to create barriers around the openings. Keep all insulation at least three inches away from chimneys and gas flue pipes.
- DON'T cover attic vents, and leave at least one inch of air flow between the insulation and the roof.
- DON'T forget to insulate and weatherstrip the attic opening.
During cold weather, water vapor from the warm inside air travels through unsealed holes and cracks, and condenses on cooler surfaces, including exterior walls, the underside of the roof and within insulation. This condensation can rot wood framing, blister paint, ruin insulation and damage the roof. Vapor barriers installed between insulation and interior surfaces can help prevent this problem.
You can purchase batt or blanket insulation with an attached vapor barrier, usually made of coated kraft paper or foil-backed paper. When using unfaced batts or blankets, or loose-fill or foam insulation, you can add four- or six-mil thick polyethylene sheeting.
If you're installing insulation yourself, remember these guidelines when using a vapor barrier:
- DO place the vapor barrier towards the warm side of the insulated area - facing downward on the attic floor or to the interior side of the wall.
- DO add a polyethylene vapor barrier on the floor of a crawlspace to reduce condensation from ground moisture.
- DON'T add a second vapor barrier to additional layers of insulation - this can trap moisture inside the first layer. Use loose-fill or unfaced batts or blankets; if only faced batts are available, cut facing every few inches to allow air to pass through.
Never cover attic vents with insulation. If your home has no attic vents, be sure to add several before installing new or additional insulation - your contractor or retailer can advise you on what's best for your situation.
For the best indoor air quality - and even greater energy savings - you can invest in a heat recovery ventilator. This device will provide continuous circulation to ensure your home has healthy air.