Did you receive an RP9 form when you were put on temporary lay-off? If so, you need to complete part B of the form to request redundancy payment, but you lose your right to payment of any notice if you do this. If you complete part B, the employer has a week to get back to you to offer you 13 weeks unbroken work or agree to redundancy. If you do not complete part B of the form, then technically 'temporary' lay off could go on for a long time. If you have not received an RP9 form from the company, you should request one completed with the actual dates.
I'm unsure as to what the case is for the period you were employed as an apprentice electrician, but the redundancy payments act states that redundancy applies to "continuous & reckonable employment since the age of 16" so I would imagine you should be covered.