Rowan Timber is an authorised designer and distributor of the JJI range of engineered I Joists manufactured in Scotland by James Jones Ltd.

The JJI–Joist system is the only fully engineered system designed and manufactured in the UK by a UK owned company.

Through the use of the bespoke, dedicated software programmes, JJI-Joists can be specified and engineered to exacting standards for applications including floors and roofs of both domestic and commercial buildings.

JJI-Joists are an accepted building material within the construction industry with third party certification from both the British Board of Agrément and BM TRADA certification.