Posted By Leigh Johnston i work for a construction company and we have a project about to start. the project involves removing floors as well as the roof on an old mill. we are intending to remove and replace each floor in turn to reduce the height that persons could fall. what i need to know is, do we have to provide safety nets below each floor bearing in mind that the distance between floors is 2.1m. i know there are other options but harnesses are not practical and scaffolding would take too long and would be too expensive. would a mobile tower situated below the immediate work area suffice? Any help would be greatly appreciated.

Posted By Denis Hands Whilst in may cases safety nets are a suitable form of fall-arrest, for them to be rigged effectively there must be suitable anchorage points, at regular intervals. Also, with only a 2.1m clearance between floors, it may be necessary to attach the nets to the supporting structure at intermediate points across the span, to prevent excessive sag. Attaching the nets in such a manner may prevent you from being able to lay new floors etc. If intermediate attachment is not practical, depending upon the distance that the nets would have to span, it might not be possible to tension the net sufficiently to prevent someone who has fallen into the net from impacting the floor below. The self-weight of the nets induces an initial sag that increases as span gets wider. Additionally, nets will sag even further when absorbing the energy of someone who has fallen into them. As an alternative, it might be worth considering the use of air-bags which are inflated below the area in which work is being carried out and provide a 'soft' landing for anyone who falls on to them. Of course safety nets and air bags are methods of fall-arrest which should only be used if you consider that it is not reasonably practicable to use a method of fall-prevention. However, I am aware that both safety nets and air bags are commonly used for the type of work that you describe. I agree with you that safety harness and lanyard would not be suitable because of only having the 2.1m clearance between floors. Good contacts are; safety nets - Higher Safety Ltd 01494 485500 air bags - Air Mat Safety Ltd 01252 360550 I hope this helps. If you need further information, please contact me by e-mail Denis

Posted By Richard Peters Another option may be the use of a safety platform erected in the room below. I know of two products, one called Safety Deck (sole suppliers of same name operating out of St Neots, Cambridgeshire) and the other very similar product produced and supplied by Speedy Hire. The major advantage of these systems is that the space below can still be used for access (the deck is modular and is supported on vertical tubes, not unlike propped formwork). Don't have any ideas of cost comparison, though.