Installation Guide

1. To establish how much insulation will be needed, measure the dimensions of the loft (and the depth of the current insulation, if any), to determine how much insulation will be needed to bring it up to 270mm (the recommended depth for maximum efficiency). Generally a 200mm top up on what is in place is sufficient.

2. DIY insulation rolls are compression packed and supplied in small diameter rolls. Measure the size of your loft hatch to ensure the insulation roll will fit through.

3. Check that the loft is properly ventilated, either where the slope of the roof meets the ceiling, or from ventilation within the roof. If the roof does not have adequate ventilation this will need to be rectified to prevent condensation build up in the roof space, which may cause timbers to rot.

4. The loft temperature will be lower once the insulation is installed, so any pipes or water tanks within the loft should be lagged to prevent them freezing. Pipe insulation and water tank jackets are available from most Builders Merchants.

1. Ensure there is adequate lighting, clear the loft completely and identify any potential hazards such as electrical cables and loose boards.

2. Wear suitable clothing including gloves, goggles and a dust proof mask, as mineral wool can sometimes irritate the skin.

3. Use wide robust planks or boards to walk on to support your weight. These should be a minimum of a metre long and span at lease three joists.

Only stand on the joists if absolutely necessary, never stand in between joists as this will not support any substantial weight.

1. Start at the corner furthest away from the loft hatch. Tuck the end of the rolls into the eaves but don't completely block them - leave an air gap of at least 5cm to ensure there is sufficient airflow to prevent condensation.

2. If there is no existing insulation between the joists, start by laying 100mm between the joists.

3. If possible any electrical cables will need to be lifted above the insulation so that they do not overheat. Cables with high currents, such as those serving cookers, immersion heaters, shower units and socket outlets are particularly important to situate above the insulation. If this is not possible the edge of the insulation must be a minimum of 75mm from cabling along their entire length within the loft area.

4. Lay a further 170mm across this first layer of insulation at right angles to the joists. At this stage take extra care, working across the loft in a line. You will be covering the joists as you go, so be sure not to lose your footing when moving about.

5. You may need to cut the insulation to fit round pipes or route cables. Butt the ends together around the obstruction. This will avoid the risk of overheating and possible fires in the loft. Do not bend or pull wiring out of the way.

6. If you need to cut the insulation, use a clean sharp knife. Always take care when cutting to avoid any electrical wires or pipes.

7. If you have a cold water tank, don't put insulation under it. Instead fold the insulation up around the sides of the tank at the bottom and then wrap the tank jacket around the tank and over the top of the ends of the insulation to form a draught proof seal. If the cold water tank is located more than 300mm above the ceiling joists it must be completely encapsulated with insulation. If necessary install access maintenance boards from the loft hatch up to the cold water tank.

8. If there are hoses for extractor fans or recessed light fittings protruding into the loft space, trim the insulation around them, leaving a gap of 150mm all the way round.

9. Any flues or chimneys within the loft must have a minimum of 75mm gap all around. Trim the insulation as required.

10. Ensure no material is allowed to enter the cavity of any wall.

11. The loft hatch also needs to be insulated. Nail or staple some insulation onto the back of the loft hatch and add a draft excluder strip around each edge to create a seal.

Any storage boards already in place within the loft must be completely removed before the insulation can be installed. If boards are unable to be removed (i.e. would cause damage) push 100mm of insulation under boards to seal joist tunnels and lay a further 270mm of insulation on top of the boarded areas.

If boards are to be refitted in the same area, remove and install 100mm of insulation between all joists. Re-fit boards and add a further 170mm of insulation on top.

Placing items directly on top of the insulation will reduce the effectiveness of the material.

Once the insulation has been installed the loft can still be used as a storage area, maintaining the effectiveness of the insulation by fitting storage boards on top of raised joists above the insulation.