In an uninsulated home, a quarter of the heat is lost via the roof.

Insulating your loft, attic, or flat roof can help you save money on your heating expenses by reducing heat loss. Loft insulation, if installed appropriately, should pay for itself many times over in its 40-year lifespan.

How to Choose Loft Insulation

If your attic is accessible and free of moisture or condensation, it should be simple to insulate – and in many situations, you can do it yourself.

Mineral wool insulation coils can be used if access is convenient and your loft joists are regular. The first layer is installed between the joists, which are the horizontal beams that make up the loft’s floor, and the second layer is installed at right angles to cover the joists and bring the insulation up to the desired depth.

When installing loft insulation, there are a few things to keep in mind

Space for storage

If you wish to use the loft or attic for storage, you should cover the joists with boards. Unfortunately, if you merely insulate between the joists before proceeding, the insulation will be insufficient.

You can raise the floor level to accommodate enough mineral wool beneath the new floor level to achieve suitable insulation. Installing timber battens across the joists or purchasing purpose-built plastic legs that fit on the joists and support the new floor are two options. To avoid condensation on the underside of the boards, leave a vented air gap between the insulation and the boards.

When fitting the boards on top, be careful not to squish the mineral wool, as this would impair its insulation value.

Green Homes Grant: Financial assistance from the government to aid with the cost of insulation.

The Green Homes Grant initiative in England assists homeowners and landlords in applying for money-saving and energy-saving vouchers. These can be used to cover the cost of everything from insulation to heat pumps to solar thermal installations. The vouchers can cover up to two-thirds of the cost of making your home more energy efficient, with a maximum value of £5,000 per household.

Lofts that are damp

Insulation prevents heat from escaping from living spaces, resulting in a cooler loft space, which may introduce or exacerbate existing damp or condensation issues. If you’re doing your own loft insulation, keep in mind that you might need to boost ventilation. Before installing insulation, seek professional guidance to determine if any damp issues can be resolved first.

A cosy loft

Installing insulation between and over the rafters — the sloping timbers that make up the roof – is an alternate option to insulate your loft. Rigid insulation boards, precisely cut to size, or foam insulation sprayed between the rafters are both options. Whatever method you choose, you will need to hire a professional to insulate your roof; this is not a do-it-yourself project.

Advantages of Loft Insulation:

  • Because the roof space will be warmer than it would be with regular loft insulation, you won’t have to worry as much about tanks and pipes freezing.
  • You don’t have to raise the floor for storage because it’s already boarded.

Disadvantages of Loft Insulation:

  • Rafter insulation is significantly more expensive than typical regular loft insulation.
  • You’ll also need to insulate any gable walls, party walls, or chimneys in the loft space, in addition to the roof. If you leave these exposed to the elements, the heat will travel through your new insulation, rendering it worthless.
  • Some firms will offer to repair your damaged or leaky roof by spraying foam insulation directly onto the roof’s underside without first repairing the problem. This is not something we recommend. Before installing any form of insulation, ensure sure the roof is dry and in good shape.

If you want to heat your loft, you’ll need to take a slightly different route and build an actual chamber in the roof.

A room in your roof

If you plan to utilise your loft as a living area, or if it currently is, you must insulate all of the walls and ceilings between a heated room and an unheated space.

  • Sloping ceilings can be insulated similarly to a warm roof, but with a layer of plasterboard on the interior.
  • In the same way as horizontal walls, vertical walls can be insulated.
  • Like a regular loft, flat ceilings can be insulated.

Ensure that all parts of the wall and ceiling around any dormer window are insulated, and that the window or any skylights are sealed with high-performance glazing. This isn’t a do-it-yourself project like the warm loft insulation. A professional installation will be required to ensure that the insulation is adequate and thorough, as well as that proper ventilation is given where necessary.

Ventilation

To keep your home fresh, dry, and healthy, air must move in and out. Any deliberate ventilation will not be blocked or sealed by a professional installer. Make sure you don’t cover any vents, grilles, or airbricks while completing any DIY insulation.

When installing loft insulation in Northern Ireland, building laws need appropriate ventilation. If there aren’t enough, this usually entails adding new vents. To discover out what you need to do for your home, contact your local building control office.

Loft spaces that are inaccessible

If you have a difficult time getting into your loft, you can have blown insulation placed by a professional who will use specialised equipment to blow appropriate insulation material into any problematic spaces. Mineral wool fibre, processed cellulose, or polyurethane foam may be used.

Roofs with a flat surface

A flat roof should be insulated from above if possible. A layer of rigid insulation board can be placed on top of the roof’s weatherproof layer or directly on top of the timber roof surface, followed by a new weatherproof layer. It’s preferable to do this when the roof covering needs to be replaced anyway. If you need to repair your flat roof anyway, you must now insulate it to meet building codes.

It is feasible to insulate a flat roof from below, but if done incorrectly, this can result in condensation problems. Flat roof insulation may save you the same amount of money on your heating bills as loft insulation. The amount of money saved depends on how much of the house has a flat roof.

Pipes, a water tank, and a hatch in the loft

Insulating your loft’s joists will keep your house warm, but it will make the roof area above colder. As a result, pipes and water tanks in the loft space may be more susceptible to freeze, necessitating insulation. If your water tank is a long way from the loft hatch, you’ll need something to walk on to get to it safely. Because of the cooler air in your insulated loft, cold draughts may enter via the loft hatch. Install an insulated loft hatch and draught-proofing strips around the hatch edges to avoid this.