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Insulating for Loft & Attic Spaces

When insulating your loft, you have to start by deciding what you actually require your roof space for, or indeed what you might use it for, because in the future this can determine how you would need to be insulating the roof space.

Below are a few examples of how to insulate your loft depending on its use:

Insulating with no use of loft space required

If you don’t use the loft space and do not foresee using it or are unable to use it for any other reason then the cheapest option would be fibreglass insulation and to insulate the floor of the loft currently at the time of writing, building regulations state that you need to install a minimum of 270mm overall thickness, this is generally a layer of 100mm between the joists and then a cross layer of 170mm over the top. This all depends on the depth of joists as if you have deeper joists than 100mm then you would insulate accordingly to meet the required level. We supply non itch fibreglass which is far easier to use and less dangerous than the old style fibreglass that would tend to give bad skin irritation. When installing fibreglass insulation in your loft space we would always recommend wearing appropriate safety face masks, gloves and goggles.

Insulating your loft for use as storage

When your loft space is going to be used as storage then you can again use fibreglass insulation in the floor this is more difficult and sometimes not practical as you would need to install loft legs and build a raised chipboard tongue and grooved flooring system across the top, this method sometimes can be impractical because of head height restrictions. There are alternative methods though when insulating your loft for storage, for example you could use a multi-foil insulation such as ‘Actis Triso Super Ten Plus‘ , ‘Thinsulex Silver’ or ‘Superfoil SF19’ these products are easy to install with just a few hand tools and minor skills involved. The multi-foil insulation is installed by stretching out across the pitch of the roof and stapling to the rafters overlapping and taping the joints so as to construct one giant sealed foil envelope, this method in conjunction with 100mm of glass wool insulation can achieve current regs in most instances. Another way of insulating could be installing rigid board insulation in between the rafters such as Ecotherm insulation or Kingspan rigid board insulation again along with the fibreglass between the loft floor can achieve current regs u values.

Insulating your loft for use as a habitable room

If you are converting your loft for use as a living area then you are required to meet current building regulations thermal ‘u’ value targets and this can be done in a number of ways using a large variety of types of insulation. It is advisable to have an architect or local building authority inspector involved in the process of product selection.

A few examples of how this is done can be Celotex / Kingspan Insulation rigid PIR or phenolic foam insulation installed between the rafters with either a layer of insulated laminated plasterboard below the rafters to remove the threat of cold bridging, alternatively a layer of Phenolic insulation or PIR rigid boards and then a separate layer of plasterboard to achieve the same as the pre-laminated boards. When installing rigid boards a 50mm air gap is required between the roof felt and the back of the insulation board to allow the roof to ventilate properly. Another method could be to insulate in between the roof timbers with PIR rigid foam insulation with a layer of multi foil insulation over the top and then a layer of plasterboard to finish, care should be taken to ensure that a 25mm air space is made either side of the foil insulation between both the rigid insulation and plasterboard as these types of layered foil insulation reflect the radiant heat and need airflow on both sides to do so.

For further information and the best prices on all insulation for your loft / attic space please do email us or call our national sales office and talk to one of our friendly sales team on (01793 791010)

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