Insulation Advice

Loft Insulation

Loft insulation has been around for more than 40 years and in that time a lot of properties and the householders within them have benefited from  its installation.
Insulating the loft can save around 30% of the heat loss from your home. As much as 20% can be saved off your fuel bills by having the loft insulated fully. This can save you between £70 - £270 a year on your heating bills. Most properties built before 1996 could benefit from an increased level of loft insulation.

Loft insulation helps to create an even temperature in your home – keeping your home warm in winter and cool in the summer.

There are several products the installers use:

  • Mineral wool (Quilt or blown)
  • sheeps wool
  • polyester fibre or expanded polystyrene
  • recycled paper, cellulose or fabric
  • hemp

In reality provided they are installed by a professional company then they will all do a similar job, keep your home warm and reduce your fuel bills.

Loft insulation has been on the increase in thickness since it was first introduced:

In the 1970s it increased from 25mm (1 inch) to 50mm (2”), in the 1980s it increased from 50mm to 100mm (4”), in the 1990s it then increased to 200mm
(8”). From 1998 the required standard as set by building regulations was 270mm or 10.5 inches, this is till the level that is fitted into existing homes

New building regulations is now recommending 300mm (12 inch) or more installed in modern new build sustainable homes.

How is it installed?

Loft insulation is laid between and over the ceiling joists in the loft. The material used is a very poor conductor of heat, so when warm air rises it is trapped underneath the layer of insulation and prevented from escaping through the roof.

The insulation is not laid underneath cold water tanks, this is so some heat can escape up under the tank to reduce the risk of the tank freezing in winter. The cold water tanks are also insulated, as is any associated pipe work in the roof space that would not be covered by the loft insulation itself.

Ventilation should be maintained in the loft, this should be done by not laying the insulation right up to the eaves. It may be necessary in some cases for additional ventilation to be installed if condensation is a problem. Ask the installer for their advice.

Think about what you need to store in your loft space, you will not be able to re-board a loft once it has 270mm of insulation, as this will sit around 180mm above joist level, and attempts to squash it down into a four inch gap can put pressure on your ceilings or make the insulation ineffective.

You can leave a small area of boards down in the loft and tell the installers not to insulate over that area, or increase the level of your existing joists by cross laying 6” x 2” timbers on top, or you could simply have a good clear out and not use the loft for storage any longer. Under current grants at least 66% of the loft area must be brought up the recommended standard.

Loft Insulation 1

Call us on 0800 975 0166 to find out about the grants you can get to have loft insulation installed professionally, in many cases it is cheaper than a DIY installation.

Loft Insulation 2

Other useful links:

Energy Saving Trust - Loft Insulation page

Green Building Store – Natural insulation products

Thermafleece - Sheep's wool insulation

Help and advice


T: (0800)
975 0166

01202 209410

Or write to us at:
4, Trinity, 161,
Old Christchurch Road,