DIY loft insulation

• Identify potential hazards such as electrical cables and loose boards, and clear the loft space
  
• Check that the loft is ventilated from spaces at the eaves or from ventilators in the roof itself. If not, then this has to be rectified before the loft is insulated
  
• Mineral wool fibres are a skin irritant so cover up well and wear gloves and a dust proof breathing mask, even when transporting the materials into the loft
  
• Never tear the insulating material – this gives off more fibres. Use a knife to cut it but be careful not to cut wires by accident. Make sure that you never use a knife with a metal handle
  
• Check you are able to fit rolls of insulation through your loft hatch
  
• Make sure you have a light up in the loft while you are working - if there isn't a permanent light, get an extension cable and a lamp. A single torch light will not be enough to allow you to see what you are doing
  
• Only stand on the joists, never between them, or you are likely to put your foot through the ceiling or even fall through it. Provide a series of boards to tread on; each one should span at least three joists to be secure

1. First of all, you need to work out how much insulation you need. Roughly measure the area you want to insulate, including the loft hatch. Also measure the size of the gap between the joists to determine the width of the quilt needed. Once you’ve done this, go out and buy some!

2. Start laying the insulation in the eaves at the corner furthest away from the loft hatch. Tuck the end of the roll into the eaves but don't completely block them – leave at least 5cm air gap to allow ventilation into the loft to prevent condensation. Alternatively, fit eaves ventilators to ensure enough airflow. Gently press the material down to stop air movement below the quilt.

3. Lay 100mm between the joists and then lay a further 150mm across this at a 90° angle. This cuts down on draughts but be careful – this will mean that the joists will no longer be visible so take caution when entering the loft.

4. Where pipe work or cables cross the joists, cut the quilt with a knife and butt the ends together under 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.

5. Don’t insulate under the cold water tank – lead the insulation up the side of the tank and wrap the tank jacket over the top of the quilt ends. If you have extractor fans or recessed lights fitted through the ceiling and protruding into the loft space, trim the quilt around this, leaving a gap of 15cm all round.

6. Don’t forget to insulate the loft hatch by fixing a glass-fibre blanket to it. Tap nails into each corner of the hatch and criss-cross string between them to keep the insulation in place. NOTE – if you have a drop down loft hatch then do not insulate the back as this as it may cause it to not latch securely.

Once you’ve finished, you must make sure all your pipes and tanks in the loft are also insulated to stop them freezing in the winter. Click here for instructions for pipe lagging. Ready made tank jackets are readily available from DIY shops.