Installing Batt Insulation
Batts are pre-cut panels of insulation and are available in a variety of lengths, widths and R-values. Batt insulation is made to fit within most regular wall framing, which are usually spaced 430mm or 580mm centres.
How to Install Batts
Installation Tips
Before installing insulation Batts anywhere, make sure electricity is turned off to the house. Make sure there are no exposed wires and that the work area you are in is free from any dangers such as open holes or broken wood. If you are unsure of how to install insulation please contact us to find a Johns Manville approved installer. This information is meant to be a general guide on how to easily install Johns Manville fibreglass formaldehyde free insulation, it is not meant to be a definitive guide on best installation practice.
- Work out how many packs you need and move them into place unopened.
- Spread the packs around inside the ceiling before opening the packs.
- Never walk on plaster ceilings. Stand on ceiling joists only.
- Place kneeling board across at least two ceiling joists before kneeling.
- Open the packages by cutting lengthwise through the side panel. Be careful to avoid cutting the product. The insulation will quickly expand to its full volume when the bag is opened.
- Gently push batts into the cavity so that it sits all the way in, especially at the corner and edges. Then, fluff it to its full expansion by pulling it forward to fill the depth of the cavity. The fit should be snug.
- Do not fit insulation over the top of downlights and maintain a space of at least 200mm away.
- Allow friction to hold the batts in place.
- Lay batts between ceiling joists starting at the furthest point from the manhole.
- Butt the batts closely together to ensure there are no gaps left at joints.
- Cut insulation about an inch wider than the space using a sharp utility knife against a safe backstop, such as an unfinished floor or other smooth, flat surface. Always cut on the unfaced side of the batt.
- For shorter spaces, cut the insulation to fit properly. Don’t double it over or compress it. Compression changes the R-value of the insulation.
- If it takes more than one batt to fill the height of a wall cavity, make sure the two pieces are butted snugly together.
Installing Wall Insulation
If there is no sarking around the exterior of the walls then it is important that the batts are secured so they cannot fall into the cavity or come in contact with the outer brickwork, allowing moisture to pass from the exterior wall to the internal lining. Foil insulation or long lasting string/twine should be fixed across the exterior face of the frame before installing the batts from the inside. Where string/twine is used, 2 lengths of twine should be fixed between each set of studs from the top to the bottom, running parallel with the studs and evenly spaced. Butt the batts closely together between studs to ensure there are no gaps left at joints.
