He then dropped down into non-League football signing a short-term contract with Aldershot Town in April 2005 until the end of the 2004–05 season. The following season, he moved to Grays Athletic, before joining Oxford United on loan in November 2006. Slabber moved to Stevenage Borough in January 2007, staying for five months before joining Havant & Waterlooville the following season. He returned to Grays Athletic in November 2008. Slabber signed for Conference South club Woking in December 2009. Slabber signed for Eastleigh in July 2010, before moving onto Chelmsford City in March 2012. Following a successful spell with the Essex club, Slabber joined Sutton United, where he scored 14 goals in 31 appearances during the 2013–14 season. This included two goals against Bromley, the club for which he and teammate Damian Scannell would sign for at the end of the season.