Described herein is a treatment method or process and wood products thereof. In particular, a product formulation of a single phase solution combining a wood preservative (durable component) with a Flame Retardant component [FR] to produce a durable Flame Retardant [dFR] treated wood product. The durable component comprises a range of copper based and non-copper based wood preservatives, while the Flame Retardant [FR] component comprises alkali metal silicates and alkali metal aluminate compounds. The durable Flame Retardant [dFR] working solution undergoes chemical impregnation (treatment) followed by a heat (fixation) process step that locks the chemical into the wood making it non-leachable. The durable Flame Retardant [dFR] treated wood products are tested for their enhanced fire performance properties. When heated, wood undergoes thermal degradation and combustion producing gases, vapours, tars and chars. Using the 'cone calorimeter' burn test method (AS/NZS 3837), durable Flame Retardant [dFR] treated wood products show a significant reduction in the following parameters: heat release rate (peak & average HRR values), mass loss rate (M LR) and smoke generated values (Smoke Extinction Area - SEA) compared to untreated radiate pine. The main tests being； accelerated weathering and burn tests (AS/NZS3837) all carried out at BRANZ, New Zealand.
