A process is provided for treating wood products including lumber, plywood and other engineered wood products comprising the steps of applying an aqueous fire-retardant impregnate and applying a coating to the surface of the wood product. In one embodiment, said process confers fire-retardant properties to the wood products sufficient to pass the extended burn test of ASTM E-84. The present invention also provides fire retardant wood products.

Provided is a flame retardant and latent hardener composition including a blend of 30-100% (by weight based on total solids) of diammonium hydrogen phosphate, and dihydrogen phosphate, 0-50% (by weight based on total solids) of monoammonium. The flame-retardant/hardener composition is prepared as a solid blend or a liquid composition, the liquid composition being an aqueous composition including a liquid aqueous solution of the contents ranging from 25% w/w to 80% w/w. Methods for making flame retarded fiber boards using the composition as flame retarder and a hardener for the resin used in the production of the boards are also provided.

A process is provided for treating wood products including lumber, plywood and other engineered wood products comprising the steps of applying an aqueous fire-retardant impregnate and applying a coating to the surface of the wood product. In one embodiment, said process confers fire-retardant properties to the wood products sufficient to pass the extended burn test of ASTM E-84. The present invention also provides fire retardant wood products.

The present invention has to do with an efficient system for coating and curing engineered wood products (EWP) in general, and the edges of EWPs in particular. An efficient system for coating and curing coatings is provided.