INSTALLING INSULATION BATTS

These days, insulation Batts are the most cost effective method of reducing energy bills.

Suggested Tools & Equipment Required

A decent knife and board to cut on
Mobile lighting if the roof space is dark or enclosed
Gloves are useful as fibres can irritate the skin
Something to kneel on that spans a couple of joists
Eye protection if you are working overhead
A face mask if the area you are working in is not well ventilated

Preparation

Measure the distance between the studs before buying your batts. Mistakes here can be costly! To do this, measure from the centre of one ceiling joist to the next. If your spacing is 450mm then use 430mm wide batts, if your spacing is 600mm please use 580mm wide batts. We offer a few options for insulation batts. See below for details.

R4 Insulation Batts

These 580mm wide, R4 rated batts will cover 12.1sqm. Each bag contains 18 batts each with a thickness of 195mm. Super soft to handle, these fibreglass batts will reduce your energy bills & enhance your indoor comfort. Click here to purchase.

R1.5 Insulation Batts

We offer 2 options in the R1.5 spec:

  1. Knauf Earthwool batts x 580mm wide (bag) – This product will cover 28.3sqm. Each bag contains 42 batts with a thickness of 75mm. This product is made from recycled glass bottles and comes in a natural brown colour. Click here to purchase.
  2. Knauf Earthwool batts  x 430mm wide (bag) – This product will cover 20.9sqm. Each bag contains 42 batts with a thickness of 75mm. Super soft to handle, this product is made from recycled glass bottles and comes in a natural brown colour. Click here to purchase.

Insulating Standard Ceilings

  • Calculate how many packs you require to complete your project.
  • If you insulating an existing roof space, you will find that batt packs should fit through the average size manhole. (You should pass them unopened into the roof space.)
  • Once in the roof space, spread the packs around inside the ceiling before opening them.
  • Never walk on plaster ceilings. Stand on ceiling joists only.
  • Place your kneeling board across at least two ceiling joists.
  • Lay batts between ceiling joists starting at the furthest point from the manhole.
  • Position the batts closely together to ensure there are no gaps at any of the joints.
  • Cut the batts to the required size to fit around any obstructions such as vents, exhaust fans and flue pipes etc., please allowing a space of at least 100mm around such areas.
  • Ensure you extend your coverage to a minimum of 50mm onto the external wall top plate.
  • Don’t throw away your offcuts until the job is nearly complete as they can be used may be used to fill small or awkward spaces.
  • Take great care with any electrical wiring you come across. Where possible, place the batts underneath electrical wires or use a spacer to create an air gap between electrical wiring and insulation.
  • Do not put insulation over or around recessed light fittings. Refer to manufacturer's recommendations as to proximity tolerances.

Cathedral or Raked Ceilings

When it comes to cathedral ceilings, your batts should be installed prior to fixing the plasterboard or prior to laying the roof. To help support the Batts, you can use string or wire, running between the ceiling joists so they remain in place.

Walls

It is necessary to secure the batts so they cannot fall into the cavity or come in contact with the outer brickwork. If contact occurs, it will allow moisture to pass from the exterior wall to the internal lining. Best practice suggests that foil insulation should be fixed across the exterior face of the frame before installing the batts from the inside. Click here to buy foil insulation.

Position the batts closely together between studs to ensure there are no gaps left at any of the joints.

Fibre cement or weatherboard cladding

A breathable foil or building paper must be used so as not to cause moisture build up. Again, position the batts closely together between studs to ensure there are no gaps left at any joints.

Installation Advice

Your insulation will only work well if it is installed correctly. Please consider the following when carrying out the project as it will help you achieve the best possible performance from your insulation:

  • Never squash bulk insulation. It needs retain its normal depth.
  • With cathedral ceilings make sure there is sufficient space between the roof and the ceiling lining for installing the recommended insulation without compressing it.
  • Keep your insulation dry at all times. Performance will be significantly reduced if the insulation becomes wet.
  • Avoid gaps in the insulation. Comprehensive coverage is paramount so ensure your batts are firmly touching against each other, the ceilings joists and the wall frames. Even if only 5% of an area is left un-insulated, a lot more of the potential benefits will be lost.
  • Do not cover electrical cables and equipment with insulation. Keep insulation clear of wiring using an appropriate separator. Have them inspected by a licensed electrician to ensure the insulation has been installed safely.

To download this page in a printable PDF format, click here