Learn how to insulate a loft, calculate the quantity of insulating material, lay loose-fill insulation.
One of the ways to make substantial savings on your home heating bills is to insulate the loft. Not only can you save money on your heating bills, you may be eligible for a grant to carry out the work.
The most common forms of loose-fill insulation are exfoliated vermiculite and mineral fibre. Loose-fill insulation material is supplied in bags, which will cover an area of approximately 1 m2. Modern loose-fill insulation material is very light so it's not recommended for loft spaces that are extremely draughty as it will get blown about in high winds, reducing its effectiveness.
When insulating a loft, remember that loose-fill materials can cause discomfort. Although extremely effective for insulation, when glass fibre, mineral fibre and rock fibre comes into contact with the skin it can cause an unpleasant irritation; therefore it is advisable to wear a long-sleeve shirt, long trousers (not shorts) and thick work gloves.
To avoid inhaling the dust from loose-fill insulation materials always wear a disposable dust mask.
Ensure there is adequate lighting in the loft to carry out the job.
Before laying the insulating material sweep the areas between the ceiling joists and remove the debris. Then seal all gaps around vents, pipes and wiring entering the loft using flexible mastic.
Laying Loose-Fill Insulation
Before laying loose-fill insulation, you need to create a barrier to maintain a gap of about 50mm (2in) from the eaves to allow air to circulate. This can be achieved by wedging pieces of plywood between the joists. Furthermore, if the depth of the ceiling joists is shallow it will be necessary to nail lengths of timber to the top of the joists to increase the depth to conform to current Building Regulations.
Wedge pieces of plywood between joists to maintain a gap of 50mm from the eaves for ventilation.
- Pour the loose-fill insulation directly from the bag into the space between the joists.
- Cut a piece of straight edged timber a little longer than the gap between the joists to use as a spreader and working backwards level the insulating material.
- Continue the process until all the gaps between the joists are filled. As with blanket insulation, do not lay loose-fill material under the cold water tank.
If the depth of the ceiling joists is too shallow for Building Regulations, nail lengths of timber to the top of the joists to increase the depth.
Use a piece of straight edged timber as a spreader and working backwards level the insulating material.