Loft Insulation

Loft Insulation

Loft Insulation

  • Attics
  • Property Clinic


I have no access to my loft void. However, I need to insulate this space as I have noticed, as we enter into the winter, that it is becoming quite cold. In terms of undertaking the work by myself, I am a bit concerned for my safety. The house was built during the 1920s and I was wondering that if I knock through this space could I expect to find the joist type loft that you would find in modern buildings in order to support my weight and for the house insulation? I am also concerned that I might encounter asbestos. Is this a possibility?


Insulating an attic is the first and best way to preserve heat in a home but unless you are experienced at building work or at least DIY then you should not undertake insulation in an attic or loft space. Besides the dangers of falling there are several other issues which need to be considered.

The first thing is to gain access to the loft itself. There probably was an access hatch at some point that may have been sealed up by previous owners. You should get a competent joiner to create a loft hatch and have a sealed and insulated item fitted. There are a number of inexpensive units available from good builder’s providers for this. Choose the best and also consider a composite unit with a ladder inbuilt.

The next process would be to survey the attic to ensure there are no infestations such as rot, insects, rodents or indeed asbestos as you note. Contact a local building surveyor who will inspect and identify whatever is in the attic and will provide advice on how best to proceed. It is very unlikely but not inconceivable that asbestos might be in the roof of a 1920s house. If any fibrous material is noticed, do not tamper with it and get expert advice – see for information.

If there are bats roosting they are a protected species under the Wildlife Act 1976 and any work in the loft must be undertaken under the direction of the National Parks and Wildlife service, see It is also possible that a 1920s roof might be slated with man-made asbestos slates and laid without an inner lining or ‘sarking’ felt, so dangerous fibres may have fallen from the underside of these slates and should be watched out for.

Make sure the ventilation at the eaves is preserved. Another thing well worth considering is fitting a “vapour barrier” under the insulation. It consists of a flexible plastic sheet at least 300microns thick laid over the ceiling members and sealed at all junctions. It stops condensation forming in the insulation and helps roof timbers that otherwise might get damp under certain conditions.

You might also consider future access for maintenance of tanks etc because supports for walking will be hidden under the insulation. A very important consideration is electrical wiring. If it is old, get a registered electrician to test it.

Apart from all that, there is no reason why a fit or able person cannot install insulation with due care taken. Most manufacturers provide DIY advice about installing insulation and you should consider the thickest you can afford but at least 300mm thickness of quilt.

Grants are available through under the Better Homes scheme and SEAI have a list of approved insulation installers so this might be your best way to proceed.

Fergus Merriman is a chartered building surveyor and a member of the Society of Chartered Surveyors Ireland.

Back To Top