The dangers of attic insulation have already been highlighted but the contractor remains in a vulnerable position in that, at the point in time when he certifies an installation, there may not be any insulation close to or covering the cables.
However, the likelihood is that the homeowner will shortly afterwards have insulation sprayed into the attic, and possibly between the floor boards to improve the thermal rating of the house. In doing this they are also creating a dangerous situation in that, if the insulation is expanded polystyrene, this will react with PVC/PVC cables, leading to a deterioration of the cable insulation which can in turn lead to a short circuit, or possibly a fire.
If, on the other hand, the insulation takes the form of the recycled paper based product which has recently come on the market, then the problem will arise from over heating of any cables carrying a heavy current such as cooker cables, shower cables, etc.
There is no easy answer to the problem but, as a minimum first step in order to protect themselves from future claims,contractors should advise their customers of the dangers of having these insulation materials fitted after the wiring has been completed. If no insulation is present when the job is being certified, this fact should be clearly noted in the comments box of the Cert so that it can be relied on afterwards as a defence if a claim arises.
Why not read the ECSSA Summer 07 Newsletter below?