A beginner’s guide to insulating your loft

man insulating loft

If you plan to use your loft as a storage space, or you have grand plans to create a brand-new bedroom or a stylish work studio, you’ll need to ensure that your attic is insulated properly. Loft insulation is required to meet Building Regulations, and it will also contribute to cost saving by making your home more energy-efficient. If you’re planning to transform or revamp your attic, here’s a useful guide to insulating your loft.

Where to place loft insulation

If you’ve recently converted your attic, or you’re looking to create a habitable or functional space, you have three main options when it comes to positioning the insulation. These include:

  • Between the rafters: with this option, the insulation has to be placed very deep to comply with Building Regulations. There is a risk of discolouration, as moisture can collect between the rafters due to cold bridges.
  • Over the rafters: this is an option for new homes or homes that are undergoing roof renovation work. In this case, a single cover is used to blanket the rafters.
  • Underneath the rafters: this option prevents cold bridges, but it can cause issues if there is a lack of headroom.

In many cases, the best solution is to position the insulation between the rafters and to add an extra layer beneath the rafters.

Loft insulation materials

There are several types of materials that can be used for insulating lofts, including:

  • Polyurethanes: this material is suited to compact spaces. The cost is higher than alternatives such as mineral wool, but the results are generally much better.
  • Extruded polystyrene: extruded polystyrene is much denser than its expanded counterpart, and it is generally recommended for use beneath floors.
  • Boards, rolls, and slabs: rolls of wool-like materials are the cheapest option. Boards and slabs are generally made from polystyrene and polyurethanes and are usually suited to floors and sloped roofs.
  • Multi-foils: these thin, foil-like sheets are made from aluminium intertwined with foam padding. They take up very little space, and they’re perfectly suited to sloping roofs.
  • Natural insulation materials: natural materials have become more popular due to their eco-friendly properties. Examples include sheep’s wool, wood fibres, and hemp. These materials are often used to insulate timber-framed walls, as well as roof spaces.
  • Blown-in materials: it is possible to blow in insulation materials using a nozzle. This technique offers an alternative to dry fixing, and it can be beneficial for insulating roofs.

For the floor of the loft, mineral fibre quilts, which are positioned between joists, are a popular choice. If you’re required to insulate party walls, mineral fibre insulation can be used with timberwork to reduce noise and improve heat retention.

How to insulate your loft between the rafters

  • Nail down battens to the rafters to ensure that the boards are flush and maintain the gap above the insulation layer: the void should measure 50mm and should offer ventilation in line with Building Regulations. This step is only required for partially-filled rafters.
  • Measure the space between the rafters before you start cutting any boards
  • Cut your boards in line with your measurements
  • Place the insulation, ensuring it is flush with the bottom of the rafters: it should not fill the total depth
  • Use an expanding sealant to fill any gaps
  • Use clout nails or timber screws to secure boards with fully-filled rafters

When you’re insulating your loft, always take care to pack in the material tightly to prevent a cold bridge.

If you’re all set to insulate your loft, hopefully, you’ll find this guide handy if not get in touch today and let us help and advise you.

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