Installing Ceiling Insulation

A well insulated home means increased comfort and decreased heating bills. And if you follow the safety and installation instructions, putting in your own insulation is actually a pretty straight forward DIY project.

Keeping Insulation Simple

Insulating your home – ceiling, walls or under?floor – is basically a process of ?filling the gaps between your house framing with an effective thermal barrier.

• You need the right insulation for the job – wall insulation for walls, ceiling insulation for ceilings, underfloor for floors.
• You need the right insulation for your area – colder areas need a higher “R” rating.
• You need to be accurate – insulation should be cut slightly oversize for a “friction” fit. Too small leaves gaps and too big compresses the insulation material, reducing its effectiveness.
• And you need to be safe. You’ll be working around electrical wiring and pipes, you’ll be working in awkward spaces and if you’re up in the roof space there’s always the danger of stepping between the framing and falling through the ceiling. Just follow the recommended safety procedures and safety-wear guidelines.

What To Wear

Old roof cavities and under?floors are dusty places at the best of times, and glass wool insulation can produce skin irritation so it pays to wear protective clothing.

Disposable overalls and taking a cool shower straight after the job is the ideal way to keep things comfortable.

Correct Clothing - Loose fitting, full cover clothing – long sleeves, long pants, or better still, overalls – will lessen the chances of skin irritation.
Dust Mask - A disposable cotton pad mask is generally suitable to help prevent discomfort. Increased protection is available with a more sophisticated mask such as a R1000 Respirator.
Safety Glasses - Safety glasses are also a good idea, particularly when installing underfloor insulation where you’re working underneath/looking up at the job.
Gloves - Rubber palmed gloves are recommended to help prevent skin irritation. Washing up gloves are fine.
Footwear - Sturdy footwear is also necessary to maintain safety. And because you’re going to be working around electrical wiring, rubber-soled footwear is a must.

Installing Ceiling Insulation

• Measure up your ceiling area (basically the same as your floor area).
• Select the correct insulation for the job (ceiling insulation) and the correct R-rating for the area you live before you calculate how many bales of insulation you need. Coverage area per bale varies with different types and grades of insulation.
• Before you start, set up your ladder, get up through the manhole/access with a couple of planks and a worklight and just have a look around. You’ll get a better idea of what the job involves (it is possible to install new insulation over old insulation, provided the old insulation is level) and you’ll be able to see if anything needs tidying up before you start. Check for exposed nails, damaged or exposed wiring and pests such as bees or wasps. Avoid working in the heat of the day as temperatures can get dangerously high in the roof cavity, and always treat all wiring as live.
• Once you’re ready to start the job, get everything set up – planks, work light, tools, a couple of bales of insulation, and get back up there with all your gear on – overalls, mask etc.
• Start in the area furthest away from the access and measure up the space between the framing. Use your cutting board and straight edge to cut 10 to 20mm oversize for a snug friction fit. You don’t want to leave gaps but forcing too-big insualtion between the framing reduces its effciency. Use your cutting board. DO NOT CUT AGAINST FRAMING and risk cutting through electrical wiring.

Use the push rod/broom handle to push the insulation carefully into areas you can’t reach.

When putting the insulation in place, ensure there is at least 25mm between the top of the insulation material and the underside of the roofing material or roofing paper. This prevents any moisture in the underlay from wicking into the insulation. It may be necessary to cut away a small section of the insulation to achieve this.

Never cover downlights with insulation. Downlights require the insulation to be cut around them to provide clearance so heat from the light is not trapped. Failure to do so can result in fire through overheating. The new, CARated, recessed downlights don’t require any clearance and incandescent lights need 50mm clearance but if you’re not 100% sure of the rating of your downlights, YOU MUST LEAVE MINIMUM CLEARANCE of 200mm. Talk to staff in the lighting department for advice on downlight ratings.

When working around plumbing or pipes, cut a slit in the insulation and wrap it snugly around the pipes.

When working around wiring, slip the insulation underneath the wiring if possible as wiring that is covered (especially in older homes) can overheat.

Don’t forget to measure and cut one last piece of insulation to fit over the access panel. Once you’ve cleared up and are ready to exit the roof space, just position it so it lowers into place as you close the access panel cover.