First Fix

This stage takes place prior to any plastering and usually at the same time as any central heating or plumbing work. First Fix can involve any of the following, depending on the type of work taking place:

• Taking up floorboards and chasing plaster out of walls to run cables
• Installing back boxes for sockets and light switches
• Protecting cables buried in walls with capping

Once the First Fix is complete, the plastering can take place and any walls and/or ceilings which have been damaged can be made good.

Second Fix

This stage should only begin once plastering is complete. If sockets, light switches and other accessories/fittings are installed before the plastering takes place it can result an in untidy finish.  Second Fix can involve any of the following, depending on the type of work taking place:

• Fitting all new sockets, switches, fittings and other accessories
• Fitting a new split-load, 3rd amendment consumer unit. Typically this will be a ten-way unit with two  RCDs protecting five circuits each. The circuits are split in this way so that if the power is lost on one side, due to a fault, the other side stays on and some power remains available.
• Inspection and testing of all circuits worked on.