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.
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 straightforward DIY project.
Steps:
Measure up your ceiling area (basically the same as your floor area).
Select the correct R-rating for the area you live in. Do this before you calculate how many bales of insulation you need. Coverage area per bale varies with different types and grades of insulation.
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..
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.
Measure and cut your insulation to fit. 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 efficiency. 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.
Leave space between the insulation and roofing material. Ensure there is at least 25mm between the top of the insulation material and the underside of the roo fing 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 at Mitre 10 for advice on downlight ratings.
Work around plumbing or pipes. Cut a slit in the insulation and wrap it snugly around the pipes.
Work around wiring. Slip the insulation underneath the wiring if possible as wiring that is covered (especially in older homes) can overheat.
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.
What To Wear
Old roof cavities and underfloors 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.
