It is important, from the point of view of energy conservation and to limit the risk of condensation in the loft, that airflow from the loft is minimised. To achieve this, the ceiling should remain well sealed.
If the householder installs products that penetrate the ceiling, the same precautions should be taken as above. The loft access trap can be a potential route for water vapour to escape into the loft space. It should be kept closed when access is not required.